OCS Study MMS 93-0013 Solid Waste Pollution on Texas Beaches: A Post-MARPOL Annex V Study Volume I: Narrative Author Anthony F. Amos Prepared under M MS Contract 14-35-0001-30546 by The University of Texas at Austin Marine Science Institute Post Office Box 1267 Port Aransas, Texas 78373-1267 Published by U.S. Department of the Interior Minerals Management Service Gulf of Mexico OCS Region New Orleans July 1993 DISCLAIMER This report was prepared under contract between the Minerals Management Service (MMS) and the University of Texas at Austin. This report has been technically reviewed by the MMS and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the Service, nor does mention of trade names or commercial products constitute endorsement of recommendation for use. It is, however, exempt from review and compliance with MMS editorial standards. REPORT AVAILABILITY Extra copies of the report may be obtained from the Public Information Unit (Mail Stop 5034) at the following address: U.S. Department of the Interior Minerals Management Service Gulf of Mexico OCS Region Public Infon~ation Unit (MS#5034) 1201 Elmwood Park Boulevard New Orleans, Louisiana 70123-2394 Telephone Number: (504) 736-2519 CITATION Suggested citation: Amos, A.F. 1993. Solid Waste Pollution on Texas Beaches: A Post-MARPOL Annex V Study, Volume I: Narrative. OCS Study MMS 93-0013. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. 90 pp. ,. "' • ' CONTENTS LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....... vii LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi 1. INTRODUCTION ................................... ·-· ..... 1 t 1.1 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2. METHODS ..............................................3 2.1 Weekly Counts .........................................3 2.2 Bi-Daily Count of Five ................................... 11 2.3 Weekly Collections ..................................... 12 2.4 Monthly Container Study ................................. 13 3. RESULTS .............................................. 13 3.1 Debris and Litter by Quantity Counted . . . . . . . . . . . . . . . . . . . . . . . . . 14 3 .1.1 Human Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.1.2 Natural Debris ................................... 16 3 .1. 3 Fishing Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.1.4 Off shore Oil Ind ustry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3 .1. 5 Maritime Commerce .-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.-1.6 Galley Waste .................................... 25 3 .1. 7 Miscellaneous Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.1.8 Beachgoer Litter .................................. 25 3 .1. 9 Indicator Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.2 Evaluation of Count Results; Errors ........................... 31 3.2.1 Accuracy of Counts ................................ 32 3.2.2 Effect of Beach Cleaning on Counts ...................... 32 3.2.3 Distribution of Items Along the Survey Beach ................ 32 3.2.4 Import and Export of Debris on the Study Beach ............. . 42 3.3 Debris and Litter by Weight ............................... 42 3.4 Ranking of Debris and Litter by Quantity and Weight ................ 55 3.4.1 Macro-Litter and Debris (by Quantity) ..................... 55 3.4.2 Micro-Litter and Uncountable Debris (by Weight) ............. 59 3.5 Litter (Containers) by Quantity, Size, Material, and Country of Origin . . . . . 63 3.5.1 Number of Containers by Type ......................... 63 3.5.2 Sizes of Containers ................................. 71 3.5.2.1 Volumes ............................. ... . 71 3.5.2.2 Weights .................................. 71 3.5.3 Container Origins (by Country) .................... ... , . 74 3.5.4 The Turtle-Bite Problem ............................. 74 4. DISCUSSION ........................................... 82 4.1 Beach Debris Survey Methods .............................. 82 4.1.1 Objectives ...................................... 82 ' 4. 1.2 The Ideal Survey Conditions . . . . . . . . . . . . . . . . . . . . . . . . . -: . 83 4.1.3 The Real World ......... . ......................... 83 4 .1. 4 Choosing a Beach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 4.2 Comparison of Four Beach Debris Surveys ...................... 84 4.2.1 Island Beach State Park ..................... . ........ 84 4.2.2 Padre Island National Seashore .......................... 85 4.2.3 Mustang/San Jose Island (CMC) ......... . .............-.. 86 4.2.4 Mustang/San Jose Island (MMS) ......................... 87 4.3 Future Beach Debris Surveys ............................... 87 i 5. CONCLUSIONS .......................................... 88 6. REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 • Vl LIST OF FIGURES 1.1 Location Map of Study Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.1 Mustang Island, Texas: Details of Survey Site ..................... 4 2.2 Survey Vehicle and Equipment: (a) HP-75 Computer in Use and (b) HP-75 Computer and Electronic Odometer and Interface ................. 9 2.3 GARBGobs and BEACHobs Templates for the HP-75 Computer ......... 10 3.1 Counting Schedule vs Day of Week ........................... 14 3.2 People-related Activities: Counts of Automobiles, Camped Cars, Camped People, Dogs, and Horses . . . . . . . . . . . . . . . . . . . . . . . . 15 3.3 People-related Activities: Counts of People Observed on Beach Survey Area, 1979-1992 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.4 Natural Debris: Counts of Portuguese Man-o-war, Cabbageheads, Pen Shells, Driftwood, and Coconuts . . . . . . . . . . . . . . . . . . . . . . . . 18 3.5 Fishing Industry Litter: Counts of Floats, Light Sticks, Dead Fish, Fishing Line, Sacks, Gloves, Green Bottles, and Shrimpboats . . . . . . . . . 19 3.6 Offshore Oil Industry-related Items: Helicopters Observed on Beach Survey Area, 1979-1992 ............................... 20 3.7 Offshore Oil Industry-related Items: Counts of Pails, Hard Hats, Write-protect Rings, and Plastic Sheeting ................. . ... 22 3.8 Merchant Marine Litter: Counts of Cardboard Cai:tons, Lightbulbs, Fluorescent Tubes, Ropes, and Hawsers . . . . . . . . . . . . . . . . . . . . . . 23 3.9 Galley Waste: Counts of Milk Jugs, Egg Cartons, Plastic Bottles, Glass Bottles, Tin Cans, and Fruit .-...-................... .. 24 3.10 Miscellaneous Litter: Counts of Plastic Pieces, Styrofoam, Foam, Plastic Bags, and Metal Pieces . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3.11 Beachgoer Litter: Counts of Clothing, Shoes, Ppaper, Balloons, Toys, Beverage Cans, 6-Pack Rings, Cups and Lids ........................ 27 3.12 Indicator Items: Bi-daily Counts of Milk Jugs, Egg Cartons, Green Bottles, Chemical Drums, and Beverage Cans -Total Items .... ... . .. 29 3.13 Indicator Items: Combined Weekly and Bi-Daily Counts of Milk Jugs, Egg Cartons, Green Bottles, Chemical Drums, and Beverage Cans ­All Observations . . . . . . . . . . . . . . . . . . . . ._ . . . . . . . . . . . . . . . 30 3 .14 Evaluation of Data: Use of Electronic Odometer, Distances and Times of Surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 3.15 Distribution Along the Survey Beach: Count of People, Camped People, Automobiles, Camped Cars, Dogs, and People-related Activities . ...... 34 3.16 Distribution Along the Survey Beach: Count of Cabbagehead Jellyfish, Portuguese Man-o-war, Driftwood, Pen Shells, and Natural Debris . . . . . 35 3.17 Distribution Along the Survey Beach: Count of Plastic Bottles, Green Bottles, One-Gallon Milk Jugs, Egg Cartons, Gloves, and Beverage Cans ...... 36 3.18 Distribution Along the Survey Beach: Count of Miscellaneous Plastic Pieces, Styrofoam Pieces, and Plastic Bags ...... . ...... ... . . .. 37 LIST OF TABLES 2.1 Weekly Debris Count Codes (1987-Present) ....................... 5 2.2 Litter Items Counted During Bi-daily BEACHobs (1987-Present) . . . . . . . . . 11 2.3 Debris and Litter Categories Used for Garbage "Collections" . . . . . . . . . . . 12 3.1 Explanation of Statistical Data for Section 3 Figures . . . . . . . . . . . . . . . . 13 3.2 Summary of Beach Usage and Cleaning ........................ 31 3. 3 Location of Landmarks on the Survey Beach . . . . . . . . . . . . . . . . . . . . . 41 3.4 Macro-Litter and Natural Debris Ranked by Total Counted -All Observations . 56 3.5 Macro-Litter and Debris Ranked by Mean Number per Kilometer . . . . . . . . . 57 3.6 Macro-Litter and Debris Ranked by Frequency .................... 58 3. 7 Percentage of Plastic Among the Micro-Litter . . . . . . . . . . . . . . . . . . . . 59 3.8 Micro-Litter and Uncountable Debris Ranked by Total Weighed All Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 3.9 Micro-Litter and Uncountable Debris Ranked by Weight per Kilometer ..... 61 3.10 Micro-Litter and Uncountable Debris Ranked by Frequency .......... . . 62 3.11 Percentage by Weight of Plastic Among the Micro-Litter . . . . . . . . . . . . . . 63 3.12 San Jose Island Study: Total and Percentage of Each Category for Each Collection . . . . . . . . . . . . . . . . . . . . . . . . . 70 3.13 San Jose Island Study: Comparison of Total Weight and Volume ......... 71 4.1 Beach Debris Survey Examples .............................. 85 .} ACKNOWLEDGEMENTS Acknowledgements are due to those who helped collect and count the debris on the beach, especially Andrea Wickham, Chuck Rowe, and Pam Plotkin. Others who helped with the field work were Judy Roberson, Paul Tressa, and Cecelia Zankas. The pre-MARPOL work was supported in part by Texas A&M Sea Grant College Program, and by the author. Other data used in this report were provided by the author. The author would also like to thank the University of Texas at Austin, Marine Science Institute, for its support. This is UTMSI Technical Report Number TR/93-001. • • ·' .· 1. INTRODUCTION 1.1 Objectives Project MMS-Beach was designed to test the effectiveness of MARPOL Annex Vin reducing the quantity of man-made debris littering Gulf of Mexico barrier island gulf beaches, specifically those in Texas. Annex V of the International Convention for the Prevention of • Pollution from Ships, 1973 (MARPOL) became international law on 31 December 1988. The Annex prohibits the discharge of plastics into the ocean and limits the discharge of other solid waste pollutants within varying distances from the U.S. coastline. The U.S. Minerals Management Service (MMS) needs to know if users of the Gulf of Mexico are observing Annex V. Ifso, then this should manifest itself in a reduction in the quantity of certain types of litter found on Gulf beaches. These materials include those readily identifiable with various operations of interest to MMS, for example, items from the offshore oil and gas exploration and production industry. The objective of this study was to compare results of beach-debris surveys done two years after, with those done two years prior to Annex V entering into force. The methods of surveying the beach had been devised by the author and were to be repeated in the post-MARPOL Annex V period. 1.2 Background The investigator started looking at litter on Mustang Island (Texas) gulf beach (Figure 1.1) in 1978 when a survey was initiated to monitor the bird population with the advent of beachfront development. At first the references to litter and debris were anecdotal, in the form of notes and sporadic measurements. In 1983 an attempt was made to estimate the quantities of both man-made and natural debris using some 40 categories of debris types. Estimates were based on the investigator's knowledge of the common items after five years and over 500 observations to that date. An index system was devised based on a 0 to 5 scale of magnitude. This method is still employed on the survey (now with 2,100 observations) and is useful in gauging the seasonality of materials washing up on the beach, especially in some categories. This method does not yield quantitative data (although curves have been fitted to some common items after numbers were counted independently and graphed against the estimates). The counts were started in 1987 with some financial assistance from the Texas A&M University Sea Grant Program. In addition to the beach-bird surveys (BEACHobs), special garbage surveys (GARBGobs) covering the same 11. 8-km stretch of beach were done at an eight-day interval. Items large enough to be seen from a slowly moving vehicle are counted; about a hundred categories of litter and debris are logged. It was on the basis of this study, done in 1987 and 1988 before the enactment of MARPOL Annex V (in force 1 January 1989), that the investigator proposed to MMS to repeat this survey some two years after MARPOL Annex V. 1 98° w 29° O'N_m:::::::;::J::::::::c::::::;::c=~==:i~~:::::t::=::C~::=~~==~ 29° 0' N 28° 30' N 28° 0' N 27°30'N 27° O'N 26° 30' N 26° 0' N 25° 30 ' N 25° 0' N Figure 1.1. Location Map of Study Sites. 2 This report contrasts the "before" ~d "after" data to see if there is any indication that MARPOL has affected the littering of Texas beaches. 1 A direct link between Annex V and changes in litter on beaches cannot be forged. However, looking at the nature of the debris items before and after MARPOL may give clues to its successful implementation and adherence to by seagoing vessels. This survey is referred to as the "Weekly Counts". About 200 such counts were made, 175 of which are used in this report (the others were special counts done in conjunction with National Cleanups and other events). • To examine smaller items, another survey called "Weekly Collections" was made in 1987-88 and repeated in 1991-1992. All debris and litter items were collected from three sites in the same beach area at the same time that the counts were done. Sites were 10-m wide and stretched from the shoreline to the high-tide line. This study was designed to quantify the smaller litter items and the "uncountable" natural debris items such as seaweed and tar. After 1988 the arduous GARBGobs counts were continued sporadically through 1990. So as not to lose the continuity of data gathering, selected easily counted items were added to the BEACHobs bird counts and done on a bi-daily schedule. These are called the "Count of Five" for the five targeted items. Finally, to identify sources of marine debris in detail, we made monthly collections of all containers on San Jose Island to the north of Mustang Island. San Jose Island is inaccessible except by boat and there is no cleaning of its gulf beach. 2. METHODS 2.1 Weekly Counts An 11.8-km stretch of Mustang Island gulf beach (Figure 2.1) is surveyed by automobile at regular intervals to determine the debris and litter load by counting. At dawn, the vehicle is driven slowly down the beach from north to south, just shoreward of the last high-tide line. The criterion for choosing various items to count was their "countability" from a slowly moving vehicle and the actual experience with the method gained in the several years of observations prior to 1987. In general, items must be large enough to be seen from the truck. This eliminates what I call the "micro-trash" (e.g. small pieces of styrofoam, plastic beads, cigarette butts). Some 84 categories were counted during the GARBGobs surveys (Table 2.1). Two, often dominant, but uncountable items (Sargassum weed and tar) were also sampled along with the microtrash during the weekly garbage collections. Items are counted individually or in groups when numbers require block-counting. Generally, only litter and debris items seaward of the latest high tide line are counted to minimize recounting items that can remain on the beach from one survey to the next. People, and some "beachgoer" items such as beverage cans, are counted wherever they are on the beach. For debris counting, the early start is chosen because beach cleanup crews from the City of Port 11t was widely believed that Annex V would take several months, perhaps years, to make an effect on the dumping of plastics at sea and reduction of litter on the beaches. In this report, the "before" and "after" dividing line is taken as the date that MARPOL went into effect (31 December 1988). In Appendix Ba comparison is made with some of our data using l January 1990 as the dividing line. 3 LONGITUDE CW) 0 / / / 97 10 g 8 s 4 • 47 BAY 47 ".:~ , w .45 45 0 ::J f­ ~ I­ 44 44 < _J 43 43 2741'...._SS~Z!ll:======)EZl~s;m-=======-~!lll!mlll!Sll========:::t'-41 g 8 7 6 5 4 10 • Figure 2.1. Mustang Island, Texas: Details of Survey Site Table 2.1: Weekly Debris Count Codes (1987 -Present) Programming and Computer Indices Code . . . . . . . . . . . . . . . . . . . . . . . . Item Brief Explanation OBS# .............. Observation Nunber JULN .................... Julian Day Starting 12/01/78 STRT .................... Start Time ­TIME . . . . . . . . . Time of Observation (Min) In Minutes and 1I1Oths DIST . . . . . . . . . . . . Distance of Observation In Miles and 1/lOOOths TOTL . . . . . . . . . . . . Total Number of Items ­TYPE . . . . . . . . . Number of Types of Debris KILO . . . . . . . . Number of 30-Sec Km Marks From Electronic Odometer General Debris and Litter Categories Code . . . . . . . . . . . . . . . . . . . . . . . . Item HUMN . . . . . . . . . . People-Related Activities NATL . . . . . . . . . . . . . . . . . Natural Debris FSHG . . . . . . . . . . . . . . . . Fishing Industry OILI . . . . . . . . . . . . . . Offshore Oil Industry MRCH . . . . . . . . . . . . . . Merchant Marine GALY ......... -......... Galley Waste MISC . . . . . . . . . . . . . . Miscellaneous Stuff BCHG . . . . . . . . . . . . . . . . Beachgoer Litter People-Related Activities Code . . . . . . . . . . . . . . . . . . . . . . . . Item Brief Explanation CARS . . . . . . . . . . . . . . . . . . Automobiles Driving or Parked PEOP . . . . . . . . . . . . . . . . . . . . . . People Day Beachgoers (Also in Cars) DOGS . . . . . . . . . . . . . . . . . . . . . . . Dogs Loose, Feral or on Leash HORS . . . . . . . . . . . . . . . . . . . . . . Horses Nearby Stables CMPC . . . . . . . . . . . . . . . . . . Camped Cars Parked Overnight Camping CMPP . . . . . . . . . . . . . . . . . Camped People Overnight Campers CTOT . . . . . . . . . . . . . . . . . . . . . All Cars Total of CARS+ CMPC PTOT .................... All People Total of PEOP+CMPP Natural Debris Code . . . . . . . . . . . . . . . . . . . . . . . . Item Brief Explanation PMOW . . . . . . . . . . . Portuguese Man-o-war Physalia physalia CAB . . . . . . . . . . . . . Cabbagehead Jellyfish Stomolophus DBRD .................... Dead Bird DRFf . . . . . . . . . . . . . . . . . . . . Driftwood INJD . . . . . . . . . . . . . . . . . . . . Injured Bird DEAD . . . . . . . . . . . . . . . . . . . . Dead Bird PENS . . . . . . . . . . . . . . . . . . . . Pen Shells Atrina BEAN . . . . . . . . . . . . . . . . . . . . Sea Beans COCO . . . . . . . . . . . . . . . . . . . . . Coconuts Table 2.1 (Continued) Fishing Industry Code . . . . . . . . . . . . . . . . . . . . . . . . Item Brief Explanation FLOT . . . . . . . . . . . . . . . . . . . . . . Floats Fishing & Seismic Research NETS . . . . . . . . . . . . . . . . . . Fishing Nets Gill, Cast and Shrimp Nets LINE . . . . . . . . . . . . . . . . . . Fishing Line Monofilament Pieces STIK .................... Light Sticks Used in Longline Fishing TRAP ............. Crab and Other Traps Used by Fishermen • FISH . . . . . . . . . . . . . . . . . . . . . Dead Fish Shrimp By-catch, Surf Fishing, Fishkills CRAB . . . . . . . . . . . . . . . . . . . Dead Crabs Shrimp By-catch SACK . . . . . . . . . 50-Lb Woven Plastic Sacks Shrimper's Frozen Catch GBOT . . . . . . . . . . . . . . . . . . Green Bottles Mexican Bleach Bottles GLOV . . . . . . . . . . . . . . . . . . . . . . Gloves Rubber/Plastic; Shrimping Use 2STR . . . . . . . . . . . . Two-Stroke Oil Bottles Outboard Motors REEL . . . . . . . . . . . . . . . . . . . . . . . Reels Cable, Fishing Line SRMP . . . . . . . . . . . . . . . . . . . Shrimpboats Seen Offshore During Obs Offshore Oil Industry Code . . . . . . . . . . . . . . . . . . . . . . . . Item Brief Explanation PLAS . . . . . . . . . . . . . . . . Plastic Sheeting Large Heavy-Gage Pieces STRP ................ Plastic Strapping Used in Shipping Boxes RING ....... Mag Tape Write-Protect Rings Seismic Survey Use HARD . . . . . . . . . . . . . . . . . . . . . Hardhats Head-wear 55GL . . . . . . . . . . . 55-Gallon Metal Drums Oil and Chemicals CARB . . . . . . . . . . . . . . . 5-Gallon Carboys W /Spouts; Chemical Containers PAIL . . . . . . . ·. . . . . . . 5-Gallon Plastic Pails W /Lids; Oil/Chemical PALL . . . . . . . . . . . . . . . . . Wooden Pallets Used in Shipping WIRE . . . . . . . . . . . . . . . . Wire and Cable LUBE . . . . . . . . . . . . . . . . Tubes of Grease ­ Merchant Marine Code . . . . . . . . . . . . . . . . . . . . . . . . Item Brief Explanation BROO . . . . . . . . . . . . . . . . . . . . . Brooms , li'~sat &ea BULB ............ ~ ....... Lightbulbs Regular aad Mereury/Sedium FLOR . . . . . . . . . . . Flourescent Light Tubes -. DUNG .................... Dunnage Wooden Structure Used in Sh~ing , CRA T . . . . . . . . . . . . . . . . . Wooden Crates Produce and Shipping Crates CART . . . . . . . . . . . . . . Cardboard Cartons ­ Galley Waste Code . . . . . . . . . . . . . . . . . . . . . . . . Item Brief Explanation MILK . . . . . . . . . . . . One-Gallon Milk Jugs Incl. Drinking Water Jugs EGGC ................... Egg Cartons Styrofoam; Usually 1-Doz Size GARB . . . . . . . Garbage Bags Full of Garbage Need I say More OCAN ............. Other Than Beverage Spray/Food/Paint • PRUT . . . . . . . . . . . . . . . . . . . . . . . Fruit Citrus Fruits Table 2.1 (Continued) Galley Waste (continued) ... VEGS . . . . . . . . . . . . . . . . . . . . Vegetables GLAS . . . . . . . . . . . . . . . . . . Glass Bottles Miscellaneous Code . . . . . . . . . . . . . . . . . . . . . . . . Item PBOT . . . . . . . . . . . . . . . . . Plastic Bottles PMSC . . . . . . . . . Miscellaneous Plastic Pieces METL . . . . . . . . . Miscellaneous Metal Pieces STYR . . . . . . . . . . . . . . . . . . . . Styrofoam FOAM . . . . . . . . . . Foam (Except Styrofoam) PBAG . . . . . . . . . . . . . . . . . . . Plastic Bags APPL . . . . . . . . . . . . . . . Large Appliances Beachgoer Litter Code . . . . . . . . . . . . . . . . . . . . . . . . Item BEVG . . . . . . . . . . Aluminum Beverage Cans 6P AK . . . . . . .. . . . . . . . . . . Six Pack Rings LGHT . . . . . . . . .. · . . . . Disposable Lighters FIRE . . . . . . . . . . . . . . . . . Spent Fireworks CUPS . . . . . . . . . . . . Disposable Drink Cups LIDS . . . . . . . . . . . . . . . . . . . . Plastic Lids TABS . . . . . . . . . . . . . . . . . . . . Pull-Tabs CAPS . . . . . . . . . . . . . . . . . . . Bottle Caps DIAP . . . . . . • . . . . . . . . . . . . . . Diapers CLTH . . . . . . . · . . . . . . . Cloth and Clothing HAT . . . . . . . . . . Hats (Other than Hardhats) SHOE . . . . . . . . . . . . . . . . . . . . . . . Shoes P APR . . . . . . . . . . . . . . . . . Paper Products BAGS . . . . . . . . . . . . . . . . . . . Paper Bags NEWS . . . . . . . . . . . Newspapers; Magazines BALO . . . . . . . . . . . . . . . . . . . . . Balloons TOYS . . . . . . . . . . . . . . . . . . . . . . . Toys Onions, Melons, Greenstuff Liquor, Softdrink:, Household Brief Explanation All Types Other Than Styrofoam All Types Other Than Floats Packaging Mainly Polyethylene Refrigerators, Stoves, etc. Brief Explanation Softdrink:/Beer From Softdrink:/Beer Packs - - - - From Beverage Cans - Disposable --All Types - - - - - Aransas, Nueces County and those hired by the condominium owners usually start their jobs later in the day. Also, for much of the year, air temperatures and humidity on a South Texas beach make lengthy observations in a slowly moving vehicle very uncomfortable as the day progresses. Driving south provides the least amount of glare from the sun for most of the year. A Hewlett-Packard HP75C hand-held computer with 24-KByte memory is used to record the data on the beach (Figure 2.2). A program (GARBGobs) has been written in HP Basic to permit the entry of data, notes and other pertinent information. To conserve memory, each type of item counted is represented by a single ASCII character. In this way, some 240 (some of the 256 ASCII codes must be reserved for normal computer operation) separate "species" can be repre­sented in memory by a single byte. The keys are reconfigured and a special template used to allow single-keystroke entry of items observed (Figure 2.3). The numerical keys are left unconfigured so that items seen in groups can be entered by pressing the appropriate key followed by the number of items seen. To permit the entry of notes, pressing the "NOTES" key unconfigures the keyboard, reverting it to a regular QWERTY keyboard. At the end of each survey while still on the beach, the program displays the totals of every category of items counted to alert the operator of any obvious errors. Back in the laboratory, programs are used to dump the data to a Hewlett-Packard 150 PC for permanent archiving on disk. Three disk files are saved: the raw data with distance information imbedded, the notes with appropriate cod.es, and the totals file. Other programs print the data in a readable form for a hard-copy record, and in an abbreviated form for pasting in notebooks. Thus redundancy is maintained for storage of the final data. A NuMetrics distance processor and RS-232 interface is connected to the truck's transmission and provides continuous output of distance travelled while the survey is in progress. At 30-second intervals, the GARBGobs program interrogates the NuMetrics and automatically outputs distance (in meters) to the HP75. Whenever the vehicle is stopped to take notes or examine a particular item, distance is output to the computer. Thus the location of items as well as the grouping and numbers are acquired during the survey. Table 2.1 lists the categories and their ASCII codes, grouped under headings indicating their use by the program or probable source. Debris collections and counts are confined to the width of beach bounded at the time of observation by the shoreline and the high tide line. On the study beach, this can vary from near zero to 40 m or more. The width is measured using a surveyor's wheel for each survey and at each of the three sites. Local weather, sea and beach conditions at the time of the surveys are measured in an attempt to relate the observed incidence of debris and litter with those physical forces that can be responsible for its beaching. Sea temperature in the surf zone is measured with a deep-sea reversing thermometer and a salinity sample collected which is later analyzed using a laboratory salinometer. Other environmental data are obtained in real-time from a NOAA/ U.S. Weather Service Coastal Marine Automated Network (C-MAN) station located on Horace-Caldwell Pier, about three miles north of the study beach. Before each survey, a program is started on a laboratory PC computer to interrogate the C-MAN via a telephone modem each hour on the hour. Data obtained includes winds, air temperature, barometric pressure, sea temperature, and tides. • 8 (a) (b) Figure 2.2. Survey Vehicle and Equipment: (a) HP-75 Computer in Use and (b) HP-75 Computer and Electronic Odometer and Interface. 9 photo NOTES Mil•• other D D D D D D D D D D D D BEACHobB © 1978, a.f.amo• car• peop dog• heli deed injd oild ewig lscp hmbd MHWK/rdhd DATE/TIME/MEM !DtDiDlDtDiD~DDDDDDD SANO/agp WILL/appl BBP/kill PPL/8MOY RKN/•hor ATS/l•P NSP/dun SPL/bank LBC/barn WPL/wpip LBBG/mock ERROR DtDlDiDtD~DrDiD~D~D~DDD LGUL/gbt RBG/fgul HGUL./bgul AOYL/ctn FORS/btn CASP/hlrk LST/cflk STN/tre• BSK/rwaw MALL/bfby GTG/agoo D~DtDlDiD~DDD,D~DDDD GBH/bpel DCC/r• CE/duck . MILK/egrb EGGC/n•hY BBOT/lh•k CHEM/rwb BEVG/mfrg AKES/cww PINT/arob DlDiDlDiD~DlDDDDDDD photo NOTES •nd other D D D D D D D D D D D D 1~87,GARBGobs © a.f.amo• car• peop dQga hare deed injd broo rooe bean LUBE/atuk reel !D~D DD DD DD DD DD D o o·o·ErErErErErEro·o·o o oEro·o·o·Ei"E5EH~5"EJ"Ef'Do PMOW/armp CABB/dbrd DRFT/pall FISH/crab PENS/fir• PBOT/crat GLAS/appl HAWS/2atr CARB/balo BTRP/reel DDDDDDDDDDDDD 0 ~ Figure 2.3. GARBGobs and BEACHobs Templates for the HP-75 Computer . .... 2.2 Bi-Daily Count of Five In 1988, I started counting selected litter items during my bird survey of the same stretch of beach covered by the MMS-Beach survey. These surveys are done on alternate days. Five categories of litter were chosen because they were easy to see from the moving vehicle and were each representative of a particular source (Table 2.2). The first two items, MILK (one­gallon plastic milk and water jugs) and EGGC (plastic egg cartons) probably have the same source: the shrimp boats, longline fishing boats and other small craft that spend more than one day offshore and are locally based. CHEM (drums, carboys and pails) are usually empty when found on shore and bear labels that indicate their use by the offshore oil and gas exploration, drilling and production industry. The majority are 5-gallon in capacity, but each year several 55-gallon drums wash ashore here. GBOT (green bleach bottles) are plentiful at certain seasons; they are small-volume (1 liter or less) plastic bottles of the popular household bleach brands sold in Mexico. Their presence on the beach is an indication that the nearshore currents are coming from the south. BEVG (beverage cans) discarded by visitors to the beach are indicators of beachgoer activity, although some are seaborne from the recreational boating and fishing industry. Table ·2.2: Litter Items Counted During Bi-Daily BEACHobs (1987 -Present) # Code Item Counted Brief Explanation 89 MILK One-Gallon Mille Jugs Galley Waste From Shrimpers and Other Small, Local Fishing Vessels 100 EGGC Plastic Egg Cartons As Above 162 CHEM Drums, Pails, Carboys Containers of Chemicals Used by the Offshore Oil Industry · 151 GBOT Green Pla8tic Bottles Bleach Bottles From Mexico; Possibly Used by Shrimpers, But Indicator of Currents From the South 204 BEVG Beverage Cans Main Source is From Beachgoers The relationship between these items and the industry sources is one which the author has established by enquiry and deduction. It is not easy to obtain direct confirmation from industrial sources on the types of disposable materials used at sea peculiar to that industry. This is especially true of the shrimping and Mexican sources. Because of distrust of "authorities" and apprehension of possible legal action against them, the target industries are reluctant to reveal details of their provisionage. Some items are unmistakably related to particular industries. The pathways by which they leave the land where they are purchased and return to the beach via the sea are often not knowable. ' 11 2.3 Weekly Collections These collections are done every eight days to determine the association of man-made litter with naturally occurring seaborne debris, to examine the nature of the "micro-trash" that is not countable, and to compare the efficacy of the counting method. Three 10-m wide transects of the beach, measured from the last high tide line to the present shoreline are cleaned of all debris, which was collected and returned to the laboratory for analysis. The transects are located at 2, 6.5 and 10 km from the BEACHobs starting point and are cleaned simultaneously with the debris counts. A surveyor's wheel is used to mark out the transects and the beach scraped of all material down to the sand. Forty-one categories of debris were regularly found in these collections (Table 2.3). Table 2.3: Debris and Litter Categories Used for Garbage "Collections" (1987 -1988) A. The Vegetable Kingdom # Code Item Weighed Brief Explanation 16 MANG Mangrove Seed Germinating Seeds 17 ALGA Algae Green, Brown, Red 18 GRAS Seagrass Mostly Green Blades 20 ·sARG Sargassllll "New" and "Old" 21 HYAC \.later Hyacinth All Stages Dec~sition 25 BEA~ Sea Bean Seeds of Tropical Plants 22 WEG \.loody Vegetation Stems, Twigs, Roots 19 VEGI Other Vegetation (e.g. Morning Glory> B. The Animal Kingdom # Code Item \.leighed Brief Explanation 24 VELA Velella "By-the-wind-sailors" 26 PMO'J Portuguese Man-o-war Physalia physalia 27 CABG Caggagehead Jellyfish Stomolophus 28 MLSK Mollusks \lhole and Fragments 30 'DIOP Diopatra Polychaetes 31 SDOL Sand Dollar \lhole and Frtlgments 32 LEPT Leptogorgia. Sea Whips (Gorgonians) 33 PENS Sea Pens "Pipe Cleaners" 34 STAR Starfish Mostly Brittle-stars 35 ANEM Anemones 40 CRAB Crabs Generally Fragments 29 INVT Other Marine Inverts Many Not Identifiable 36 INSC Insects 39 FISH Fish 37 FETH Feathers c. Man-Made Items Code Item \.lei ghed Brief Explanation ~ 1 PLAS Plastic Plastic Bags, Pieces 3 STYR Styrofoam Pieces 5 TARB Tar Tarballs 6 CIGS Cigarette Cigarette Butts 7 PBOT Plastic Bottle Miscellaneous 8 GLAS Glass Pieces 9 CLTH Cloth Clothing, Fragments 10 BULB Light bulb Including Flourescent 11 PAPR Paper Cartons, Pieces 12 CUPS Cup Styrofoam, Paper 13 MILK Hilk Jug 1-Gallon, Plastic 14 EGG Egg Shell Fragments 15 ROPE Rope Polypropylene 23 VEGS Vegetables Onions, etc. ' 2 \JOO() \.lood Ounnage, Pieces Lunber 4 ALUM Alllllim.ITI Foil 38 ROCK Rocks Some Natural y 41 MISC Miscellaneous Unidentifiable "Stuff" 12 2.4 Monthly Container Study San Jose Island is inaccessible except by boat or airplane. The beach is not cleaned of debris and hence litter accumulates there until removed by tides or storms, or buried by drifting sand. All containers on a 250-m transect (marked by surveyor's wheel just north of the North Jetty of the Aransas Pass) along San Jose Island (Figure 1.1) are collected and brought back to the lab for examination. All containers, plastic, glass, metal, and cardboard are collected from the shoreline to the dune line. The material is examined for type, place of origin, color and volume in an attempt to see what percentage of marine litter comes from what countries and what identifiable source (merchant-marine, commercial fishing, etc.). 3. RESULTS The diagrams presented in this section show histograms of either counts or weights per kilometer of beach (depending on type of survey) plotted as a function of time. Each section is organized by groups representing probable sources of the debris as outlined in Table 3.1. In the left panel, histograms for each individual survey are shown;· in the right panel, all pre­MARPOL survey means (April 1987 through December 1989) are compared with post­MARPOL (Jan 1990 -Jul 1992) means. Each page contains several panels grouped by similarity of source or types of items observed. The grouping is based on that outlined in Table 2.1. Sampling frequency is shown at the base of the bottom-most panel on each page. A linear regression line is plotted to scale, but shifted to the mid-point of each vertical axis (because the line would otherwise be "lost" in the data bars). This is due to the extreme noise in the data, a feature of marine debris beaching frequency which makes interpretation of trends difficult. Basic statistics are listed between the left and right-hand panels. Table 3.1 gives an explanation of the data. Table 3 .1: Explanation of Statistical Data for Section 3 Figures Tot Total quantity or weight of material were it all to have collected and stayed in the same kilometer of beachfront nT% Percentage of times the item was present on the beach Max Highest count or weight per kilometer on any single survey Meanl Mean of all observations (n) Mean2 Mean, not including those observations when this item was missing SD Standard deviation of linear regression of all observations against time Note that vertical axes of the panels are annotated m scientific notation to accommOdate the wide range of values encountered while the statistical values are given in decimal notation. Because of the huge range of values encountered, these graphs are not plotted using the same scale so attention must be paid to the scale annotation in order to compare magnitudes. The right-hand panels show the simple means of all pre-and post-MARPOL observations. Note the contrast between the "slope" of the left-hand panel regression lines and the height difference of the histograms on the right. This is due to the difference in scale used on the two panels. The long-term means are usually one order of magnitude less than the scales needed to depict the full range of items counted or weighed on each survey, hence the slopes appear greater on the right. In both cases scaling is chosen to maximize the visibility of the smaller counts or weights yet maintain a readable scale. The Y -ordinate is selected based on the closest value of the maximum count or weight that is less than the following: 0.2, 0.25, 0.4, 0.5, 0.6, 0.75, 0.8, and 1.0 x lQY, where y is some power of 10. A program was written for this project to display the data in this fashion. 3.1 Debris and Litter by Quantity Counted The weekly counts are actually done at eight-day intervals to avoid conflicting with our bi-daily BEACHobs. This also permits sampling to be done on every day of the week rather than on the same day each week. A typical sequence of observations and their relationship to day-of-the-week is illustrated below (Figure 3 .1). Every seventh and eighth week, observations are made on Saturday and Sunday when the litter on the beach might be increased by the larger number of people using the beach on those days. Although this might appear to obscure the marine source of beach litter, it afforded the opportunity to observe the addition of beachgoer debris. Many volunteer beach cleanups and debris assessments must be done on weekends when sources of litter other than marine-borne may be present. CAY OF 085 MON TUE '+'ED THU FR I SAT SUN MON Figure 3.1. Counting Schedule vs Day of Week. 3.1.1 Human Activity Although human activity is increasing on the South Texas gulf beaches, at the same time the nature of that activity is changing in a way which may affect the beachgoer litter left on the beach. In the late 1970's and up until the mid-1980's, several condominiums were built on the dunes fronting the Mustang Island gulf beach. Prior to that time, the only access to the 11. 8-km stretch of beach was by automobile. The condominiums provided access to the beach at many points along the stretch while many people driving automobiles were reluctant to drive far on the sand and the main concentrations of people and beachgoer litter were at the 14 , two Access Roads. On the other hand, it took several years for the condominiums to become popular with visitors, but ultimately, while both people and automobile traffic have steadily increased, the ratio of people-to-cars has increased at a higher rate (i.e., there are fewer people visiting the beach by car than are coming there via the condominiums). People visiting by walking to the beach across the dunes from the condos are also less likely to bring as much litter-producing material with them as are those in automobiles. It is quite common to find evidence of litter left by people visiting by car the morning after their visit. It has been quite popular for people to camp on the beach, driving their cars or recreational vehicles to a spot near the dunes and staying for one, two, or occasionally more nights. This activity, which can also be litter-producing, seems to have declined in the past few years. Figure 3.2 shows some of the people-related activities noted during the weekly counts. Note the increase in people, decreases in automobile traffic and beach-camping and increase in horse traffic from a riding stable located just to the south of the study area. An even more dramatic picture of the increase in human activity on the beach is shown in Figure 3.3 taken from the investigator's 15-year study of Mustang Island gulf beach. 1a.o ,... a c 7.5 ~ 5.0 ~ . I! e K 2.s • ... ... • • a.a Figure 3.3. P~ple-related Activities: Counts of People Observed on Beach Survey Area, 1979-1992. 3.1.2 Natural Debris A casual observer of man-made litter on the beach would see that the anthropomorphic material is frequently mixed in with natural debris, most often with the pelagic weed Sargassum natans. A closer inspection shows that along with the weed there are many other vegetable and animal species present among the natural debris. Common among these are seagrasses, water hyacinth, mangrove seeds, driftwood, various gelatinous organisms (medusae and Portuguese Man-o-war), bundles of gorgonians, and mollusc shells. Tarballs are also frequent among the debris at the shoreline. The observer might not know when these various items come ashore but would get the general impression that spring and summer time are when most of the debris is beached. As a former casual observer of these beachings, I attempted in these studies to quantify both the natural and man-made debris to see if indeed there was a correlation between the beaching of the two, and to observe the seasonal and long-term patterns to both kinds of material. Some natural debris items selected for this count include driftwood, coconuts, medusae, and the large mollusc Atrina (pen shell). However, the most numerous natural debris items, especially Sargassum, are not countable in this fashion. Almost certainly, concentrations of all types of floating debris are mixed in with the Sargassum weed which collects in windrows and large patches offshore in the Gulf and often washes ashore together on the high tide. This uncountable natural and not-so-natural debris is evaluated by weight during the weekly collections study (section 3.3). For the following, refer to Figure 3.4. Portuguese Man-o-war (Physalia physalia, referred to as PMOW from here on) come ashore mainly in the spring and summer, and occasionally in winter. The cabbagehead jellyfish (Stomolophus) is a winter and spring item. Pen shells appear in fall and early winter, coconuts in summer, and driftwood year-round. Apart from their "countability", which is not easy at the best of times, the reasons for looking at these items rests in their probable origins. PMOW is associated with the tropical waters of the Caribbean and central Gulf of Mexico, cabbageheads are often abundant in the bays, pen shells are inhabitants of the shallow nearshore region where sunken and waterlogged litter items are often concentrated, and coconuts are borne into the sea by the rivers of Mexico or from tropical beaches there and in Central America. Driftwood presents a special problem. Some is the result of tree-cutting both in Mexico and the U.S., some is from erosion of river banks during flooding and storms, some is in the form of dunnage, and some is from the degradation of piers, docks, and abandoned or wrecked vessels. Hence it may be both natural and "man-made". In Figure 3.4 pre-and post-MARPOL information is given for contrast with the man-made debris, although (with the exception of dunnage which shows little trend) MARPOL has no bearing on beachings of these items. 3 .1. 3 Fishing Industry Figure 3.5 groups commonly found items that almost certainly come from the offshore fishing industry. Off the Texas coast this is restricted to shrimping and a much smaller longline fishing industry. Some items could overlap with other sources such as the seismic exploration and recreational fishing industry. The floats in the top panel are usually from fish nets or lines. The trend has been decreasing and the type of floats has changed in the past few years. Fewer of the metal and plastic deep-sea floats come ashore now; they are quite a rarity where they were once commonplace. This may reflect less effort by foreign fleets in the Gulf of Mexico as EEZ regulations came into law. The cold chemical light sticks are used by longliners to attract fish to the baits and are purchased in bulk. They are used only once. These have declined in the post-MARPOL era. Dead f"ish are often recognizable (by species composition) as being the by-catch from the shrimping industry. Some are left by local wade fishermen who consider them "trash". An increase in beached fish has been observed. Monofilament f"ishing line has its origin mostly from recreational fishing. It has decreased. Fifty-pound woven plastic produce sacks are apparently used by brine boats in the shrimping fleet to bag shrimp for processing at sea; post-MARPOL, they have increased on the survey Count of POATUGESE MAN o·wAR n-m Tot-6120 1 nn:-66.5 Max-1399 . 7 Mean1-34 . 97 Mean2-51 .00 i~ . ~llllllilllllll11111 ! I i :···•)I so-126 . 96 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL Count of CABBAGEHEAD JELLYFISH n-175 Tot• 1103 .6 nU:= 61. 7 Max= 136.0 Mean1= 6 . 30 Mean2• 10 . 21 SO= 17. 50 i~~lrllln?L·I·;, .....iw[ ·. i ·I l11~11~11f~:~ i 0.0 0.0 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL Count of PEN SHELLS n• 175 Tot= 499.5 nU:• 65. 7 Max• 62.8 Mean1• 2 .85 LJ 6.0 : l Mean2• 4 . 34 so-9.42 0.0 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL Count of DRIFTWOOD n-175 2.0 Tot-2821 .6 n• 100 nn:-97.7 Max-353.4 Mean1-16 . 12 Mean2• 16 .50 1111:.: i so-38."1"1 0.0 PRE/POST-MARPOL n-175 ~to.o_ Tot• 12. "1 nn-22 . 2 Max• 3 .2 Mean1• 7 . 11 Mean2• .31 so-. 27 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL l~·~•iiiiil!llflillllllllilill -~:~i ...... •lllllllllllllmll11•1•111 I 111 SAMPLING FREQUENCY Figure 3.4. Natural Debris: Counts of Portuguese Man-o-war, Cabbageheads, Pens Shells, Driftwood, and Coconuts. 18 5.0 -;::; Tot-73 7 nn ;-73 1 Max-3 2 Mean1-42 Mean2-57 so-.56 11~n PRE/POST-MARPOL n-175 Tot= 235.2 nTX= 65. 7 II f5 Max= 36.8 Mean1= 1.34 Mean2= 2 . 04 so-3 .60 ~i:~i ­ PRE/POST-MARPOL n• 175 Wll100_ Tot• 113.2 nTX= 77 .1 Max• 12.6 Mean1• .64 Mean2= .83 -:::: so-1.47 0 .0 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL Count of FISHING LINE n-175 n-75 5.0 Tot-59.3 nn:-64.!S Max-4 .6 Meani-. 33 Mean2-.!52 l~:~•illlli\111111111 11111 1:~ i .... so-.60 0.0 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL Count of PRODUCE SACKS n-175 n• 100 Tot-U3.4 nu:-84.5 Max-5 .8 Meant-.64 Mean2-•76 so-.78 l~:~•Ilill1!11iil1illl ~lllllllff! 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL Count of GLOVES n• 175 Tot• 266. 7 ~2 -0 nTX• 86.B Max• 18.9 - Meanfa 1.52 Mean2a 1. 75 i~:~• il\lflitlfllllll!llll,11111 -:·:i so-2 . 29 o.o o.o 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL 11111111111111111111 lllllmllllll I 111 ....UllB SAMPLING FREQUENCY Figure 3.5. Fishing Industry Litter: Counts of Floats, Light Sticks, Dead Fish, Fishing Line, Sacks, Gloves, Green Bottles, and Shrimpboats. Count of GREEN BOTTLES (MEXICAN) iHltlllilJillili.: ,iJ1..1 1t I!~~~):;:~:1987 1988 1989 1990 1991 1992 11 2 . 5 ~ ~HPRE/POST-MARPOL Count of SHRIMPBOATS !}ll11 11111l1lll1l.ll.llll,,l.l!.l l•••­'·•••.1, r :,•••••••·••••••••······ 1 ,••••,•••• J••••••••-.••••-••••• I0 . 0 .....l....... ___.....__....,._..............__ ....L....I.........._.....t.....__............,,................:::__::::::__:::: ,__::::, __::__<:.....u__: __,"":-­:::: .............._....._............. 1987 1988 1989 1990 1991 1992 n­175 Tot= 12 . 2 nTX= 19 . 9 Max• 1 . -4 Mean1 • 6 . 99 Mean2= . 37 SD = . 19 11 1 J~ !ll· !ff!o .o PRE/POST-MARPOL llllllllllllllllllUll llllHUlllllll I 111 SAMPLING FREQUENCY Ill 111111111111111111 Figure 3.5. (cont.) Fishing Industry Litter: Floats, Light Sticks, Dead Fish, Fishing Line, Sacks, Green Bottles and Shrimpboats. Count of HELICOPTERS n• 788 2.5 U> ;t Tot• 1310 2.0 c I nn:• 38.3 ~ 1.5 Max• .9 ~ 1.0 Meant• . 14 E Mean2• 5 . 39 0 .5 )JI. ....... !n1 :~JL1M.1Ml.wll~LM~llJJ DI so-.10 0.0 0.0 • 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 YEARLY MEANS . ··-••:•·-·-··•1•1111111 SAMPLING FREQUENCY . Figure 3.6. Offshore Oil Industry-related Items: Helicopters Observed on Beach Survey Area, 1979-1992. beach. Rubber or plastic gloves are used on shrimp boats; they have remained at the same level before and after MARPOL. Green bottles from Mexico are ribbed plastic bottles, usually 750 ml or 1 liter size, of two or three popular brands (" Clarasol", "Cloralex ") of household bleach. They appear on the beaches in a disproportionate number compared to other Mexican domestic items. It is believed that they are used by the shrimping fleet, perhaps to prevent a bacterial shrimp infection known as black or brown spot (Cipriani, et al. 1980). Counted weekly, they show a post-MARPOL decline (but see section 3. 1.2). Finally, the shrimpboats themselves are counted. These are the boats visible from the beach as the surveys are done. They are seldom numerous in this area, and their numbers have declined, particularly the so-called "Bay Boats" shrimping close to shore for white shrimp. 3.1.4 Offshore Oil Industry Several platforms and other structures dot the marine landscape visible from the survey beach. Exploration and drilling activities are commonplace sights from the beach. Jack­up rigs, work boats, "mud" boats and helicopters are indicators of the service industry's activities. There has been a decline in the offshore oil industry in recent years. As evidence for this decline, Figure 3.6 shows the trend since 1979 in the number of helicopters counted from the survey beach. Figure 3.7 includes four items typical of this industry. Five-gallon (usually) plastic pails that contain chemicals and oils are used offshore in drilling and maintenance of platforms and rigs; there has been a notable reduction in these items since MARPOL. Protective hardhats are commonly washed ashore, often bearing decals ofcompany names identifying their source. A slight increase in hardhats has been recorded post-MARPOLe One item which has essentially disappeared from the beaches are the pl~tic write-protect rii!gs used by seismic research vessels to protect data recorded on magnetic tape from being over­written. There has also been a drop in the number of pieces of heavy-duty plastic sheefriing on the beach since MARPOL. This material is used to cover palletloads of supplies and equipment; its source is primarily offshore oil activity, but could· also have other industrial sources. 3.1.5 Maritime Commerce The merchant marine industry contributes to the marine debris on the study beach, but the distinction between items typical of this industry and those of the offshore oil and fishing industries is often blurred. All use certain types of supplies and containers that ultimately become beach litter, but certain items may be typical of that particular industry. Perhaps unique to freighters and tankers plying the Gulf is the use of one-liter cardboard cartons of long-life milk (milk which has been irradiated or heat-treated and requires no refrigeration). Also most of the foreign (with the exception of Mexico) litter on the beach has its source on merchant marine vessels which are often foreign-flagged and take on supplies in European, Middle Eastern, South American or Asian ports. In Figure 3.8, post-MARPOL reductions were recorded in cardboard cartons, lightbulbs and fluorescent tubes, while ropes and hawsers show a slight increase. Count of 5-GAL PLASTIC PAILS n­175 !,~ • ~lltllllll1ttlll .i ,/ , · 1~,~~; i ii I~[!~~=::·;:1987 1988 1989 1990 1991 1992 n­75 11111 I'll !~ ~ !0 . 0 PAE/POST-MARPOL Count of HARO-HATS 1987 1988 1989 1990 1991 1992 n• 175 Tot2 6 . 8 nU:= 22 . 2 Max • . 6 Mean1z 3 . 92 Mean2• . 17 so­9.25 11 5 . 0 ~ (\J;H 0 . 0 PRE/POST-MAAPOL Count of WRITE-PROTECT RINGS : ~: ~ lllt11111llili]llilll;lllllllllllilll,lllll1l l11 111 1 1987 1988 1989 1990 1991 1992 n• 175 Tot• 17.4 nTX• 24 . 5 Max• 3 . 0 Mean1• 9.98 Me11n22 •.40 so­. 29 IJ2 . 5 --;~ i 0.0 PRE/POST-MARPOL Count of PLASTIC SHEETING 1987 1988 1989 1990 1991 1992 n• 175 Tot• .406.6 nTX• 91 •.4 Max• 21.3 Me11n1• 2.32 Me11n2­2.!5.4 so­3.13 LJ5.0 -;H 0.0 PRE/POST-MARPOL •111m11a11m1111a1•111 1 111 SAMPLING FREQUENCY ..... Figure 3. 7. Offshore Oil Industry-related Items: Counts of Pails, Hard Hats, Write-proteCt Rings, and Plastic Sheeting. 1987 1988 1989 1990 1991 1992 n­175 Tot­139 . 1 nn:­85 .7 Max­4 . 4 Mean1­.79 Mean2­.92 so­. 81 n-75IIli'll!ff!0.0 PRE/POST-MARPOL Count of LIGHTBULBS !~ . ~l•lllllllllllllllliilllilllllllllllllo .o 1987 1988 1989 1990 1991 1992 n­175 Tot= 225 . 6 nT%= 81 . 7 Max= 12 . 5 Mean1• 1.28 Mean2• 1.57 so­1.81 2 . 0 1.5 ~ ::: PRE/POST-MARPOL Count of FLUORESCENT TUBES n· 175 !~:~•lllllflll;lillllllllllfI §~~E~:1987 1988 1989 1990 1991 1992 11 4 . 0 -:::: 0.0 PRE/POST-MARPOL -; 3.0 ~ ~ 2.0 ~ 1.0 Count of ROPE AND HAWSERS ,. 0 .·O .Wa.il&IUiii 1987 1988 1989 1990 . 1991 1992 n­175 Tot­981. 7 nn:­Max­37 .6 Mean1­!5.61 Mean2­!5.8<4 so­6.6<4 10.0 n• 7 0114'::: :0.0 PRE/POST-MARPOL Coun~ of TUBES OF GREASE 2.5~~~""""~~~~~~~~~~~~ ~ 2.0 0 ~ 1.5 1.0 E ~ 0.5• 1987 1988 1989 1990 1991 1992 n­175 Tot­23 . 6 nT"­<4<4 . 5 Max­2 . i Mean1­. 13 Mean2­.30 so­.2<4 2 . 0 -~ i:~ ~ PRE/POST-MARPOL •11111111111•1111•1•111 I 111 SAMPLING FREQUENCY ··-· Figure 3.8. Merchant Marine Litter: Counts of Cardboard Cartons, Lightbulbs, Flourescent Tubes, Ropes, and Hawsers. 24 3.1.6 Galley Waste The litter generated in ship, boat, and platform kitchens is commonly found on the survey beach. It is comprised of usually empty bottles and food cans, cleaning and toiletry products, coffee grounds, vegetable peelings, and food-packaging materials. Some items such as the numerous one-gallon domestic milk/water jugs almost certainly come from the shrimping fleet. Others could come from any of the other sources where food is prepared and people are accommodated offshore. In Figure 3.9, post-MARPOL declines have occurred in all of the items in the diagram (milk jugs, egg cartons, plastic and glass bottles, cans and fruit). 3 .1. 7 Miscellaneous Items The source of the miscellaneous items shown in Figure 3.10 cannot be easily identified; yet they form the most numerous types of litter on the beach, especially the plastics. The only item to have increased since MARPOL is the miscellaneous plastic pieces, a catch-all category consisting of broken hard-plastic peices. This does not include styrofoam or plastic-bag peices or lids, but plastic cutlery, combs, toothbrushes, fragments of bottles and lids are included. Styrofoam pieces have become noticeably less numerous on the beach, as have plastic bags. However, a typical problem with evaluating many of these items is that there is a great spike in the plastic bag "crop" in the fall of 1988, and the standard deviation is three times the mean. 3.1.8 Beacbgoer Litter The final group'·of materials has been designated beachgoer litter, meaning that its probable source is from visitors to the beach who leave their litter discarded there. Again, it is not possible to say with certainty that all of this material is left by beachgoers. Some could come from recreational boats fishing offshore, or could wash out of the bays. The most typical of this type of litter is aluminum beverage cans; in Texas these are mostly beer cans, but also include soft drink cans. Numbers of these cans have remained nearly constant, · but the associated plastic six-pack ring which presents an entanglement danger to marine life has declined. Paper products, plastic toys, and balloons have increased while drink cups, clothing, and shoes have declined (Figure 3.11). 3 .1. 9 Indicator Items After the first year of GARBGobs was completed in April 1987, it seemed desirable to try and assess certain key items of debris more frequently. Figure 3.12 shows the trends in the five items over 501 observations (334 for beverage cans which were not included in the counts until mid-1989). The result is a post-MARPOL decline in all of these categories with the exception of the Mexican green bottles. Because these items were counted on both GARBGobs and the BEACHobs count of five, we combined the two data sets to produce Figure 3.13. Now with an almost continuous set of data (n=667) from 1987 to 1992, the trends remain very similar; reductions in all items with a very slight increase in the green bottles. There is !i· ~ llli11ii1;!ilii;~NEOUi~,1llilii 1987 1988 1989 1990 1991 1992 PC n­175 Tot­3339 . 7 nn;­97 . 7 Max­243 . 6 Mean1­19 .09 Mean2­19 .53 so­31 . 21 11 2. 5 -~n PRE/POST-MARPOL Count of STYROFOAM PIECES !~ :~lllifllii111liiii11iltliifli111 1987 1988 1989 1990 1991 1992 n­175 Tot• 12723.5 nlll:= 99 . 9 Max= 993.4 Mean1= 72 . 70 Mean2= 73 . 54 SD= 123 . 59 nz 175 Tot= 174.3 nl:ll:• 95.1 Max• 5 .6 Mean1• . 99 Mean2• 1.17 so­1.15 11 10 . 0 5 ~ ~ i PRE/POST-MARPOL 2 . 0 01.5 (0 ..... ~:: i 0.0 PRE/POST-MARPOL Count of PLASTIC BAGS Ij:~•lllllillllll1llll 1987 1988 1989 1990 1991 1992 n• 175 Tot• 6101 . 4 nn:­98. 8 Max• 1179.8 Means• 34. 86 Mean2• 35 . 26 so­92. 4'7 - Count of MISCELLANEOUS METAL PIEC ii•~•1111fi1111111ltr11111rl~11 ~1~:~·~ 1987 1988 1989 1990 1991 1992 I ·-•OO r·o --~:~;PRE/POST-MARPOL 1111111m11u111111111n1mma11 1 111 SAMPLING FREQUENCY ...... Figure 3.10. Miscellaneous Litter: Counts of Plastic Pieces, Styrofoam, Foam, Plastic Bags, and Metal Pieces. Count of CLOTH AND CLOTHING H~tlllll!.1.LI l.~.J..L, I 1987 1988 1989 1990 1991 1992 n­175 Tot-53 .7 nu­70 . 2 Max­3 . 8 Mean1­. 30 Mean2­.43 so­. 46 1987 1988 1989 1990 1991 1992 L.J!OO -~~!0 . 0 PRE/POST-MARPOL 1987 1988 1989 1990 1991 1992 4 . 0 3 . 0 ? ~ :: ~ 0 . 0 PRE/POST-MARPOL Count of BALLOONS 11 6 . 0;:; ::: i 0 . 0 PBE/POST-MARPOL Count of TOYS '­1987 1988 1989 1990 1991 1992 n­1~5 Tot­32.2 nn:­416 . 2 Max­2 . 3 Mean1­.18 Mean2­.39 so­. 35 • 2 . 5 _ .... ni PRE/POST-MARPOL 111111111ma11111111a1m111 1 111 ••mm• SAMPLING FREQUENCY Figure 3.11. Beachgoer Litter: Counts of Clothing, Shoes, Paper, Balloons, Toys, Beverage Cans, 6-Pack Rings, Cups, and Lids. Count of ALUMINUM BEVERAGE CANS 1754 · 0 j·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·i ··········· ,,, ... : :.... :-,···· ~/:::::·:··::·....... 1 ~:t­7 03 . 0 ~;0 •. o: •·._.·._.•.·.:(_ .···:··:_:_.:•... _•l_.nf 1.•.i.i. 1 .•.•-·•:..i:1 .~.• . i......i. •···· il·!_.••.·.t.••w­·.t.l•.•l. _..)_:. ·_·•. ·.i.-1i._..••__.ii.i_:•..:·· --·· •.·····-········.·····,·•.••.•••_:_• .•. ' .:i_ ·:.1•• ••.. -._·······-··-· r -· ··········._· .. ·.·.·_•._..·. ··.·.•.•····.···················· ·······~·· •••·.···········•·r·•·•.•·•.••••••..:·...· ·~·;.. I _•·.····._ ..••••·.·····J_• _•.· ····•..•...•I.. .. . • :::~i-:: 4~01 ~ _ ._:_J:B %i' : ~ :::_)1: : ·.•: • .·.· ••.::.• · M 5 e 0 a-n2­4 . 12 4 . 0 4 /: f ' ~!!!! !: -­1987 1988 1989 1990 1991 1992 111 5 . 0 5 ~HPRE/POST-MARPOL Count of SIX-PACK RINGS n­175 !~ ~lll\ll 11llllllllllil lli11111t;111~11iii.lit I~[~~~i:l:~: 1987 1988 1989 1990 1991 1992 n = 75 11 1.. !· l:~ · ':il · n: 0.0 PRE/POST-MARPOL Count of DISPOSABLE DRINK CUPS l]lllll.1. .1 I; 1..1 ~ .1.. I~~~~;;~:~·i:1987 1988 1989 1990 1991 1992 I ·-•OO f10 0 _ : 0 . 0 PRE/POST-MARPOL Count of LIDS (PLASTIC) l~:~•llltlllilfltllll0.0 1987 1988 1989 1990 1991 1992 n­175 Tot• 912.9 nn:­95 . 4 Max• 40 . 4 Mean1• !5.21 Me11n2­!5 . 46 so­7.04 . ~10. 0 _ :::; 0.0 PRE/POST-MARPOL m11111111111m1111••11i 1 111 SAMPLING FREQUENCY ..... Figure 3.11. (cont.) Beachgoer Litter: Counts of Clothing, Shoes, Paper, Balloons, Toys, Beverage Cans, 6-Pack Rings, Cups, and Lids. 0 ~ E .>£ '.. E .>I. '.. e .>I. '.. MILK 1991 1992 1987 1988 1989 1990 1991 1992 n­175 Tot­491.9 nT~­90 . 2 Max­50 . 4 Meant• 2 . 81 Mean2­3 . 11 so­4.89 n­175 Tot= 404 . 2 nTX• 89. 7 Max• 15 . 7 Meant• 2 . 30 Mezm2• 2.57 so­2 . 73 Tot• 335 . 6 nn:­80.5 Max• 27 .8 Meant• 1.91 Mean2• 2 . 38 so­3.54 1111 4.0 -::~ 0 . 0 PRE/POST-MARPOL 4.0 0 ~ ~ i PRE/POST-MARPOL 2 . 5 -2.0 ~ ;:n 0.0 PRE/POST-MARPOL 0 10 . 0 ( 7.5 ~ .?$ 5.0 ~ 2.5 ....... ... 1987 1988 1989 1990 1991 1992 n• 175 Tot• 67 . 2 nn:­Max• 6.9 Mean1• .38 Me11n2­.64 so­.75 n• 75 11\tl~:~ !0.0 PRE/POST-MAAPOL ~ 3.0 .?$ 2.0 e .>I. 1.0 ~ 0.0 JillilllllmillfillllbilllWBIEEiliillllillifillllll&iLllUUJ 1987 1988 1989 1990 1991 1992 Tot• 703 . 0 nn:­99 . 4 Max• 34.7 Mean1• -4 . 01 Hean2­-4 . 04 so­4.12 111 5.0 -~:H PRE/POST-MARPOL Count of TOTAL NUMBER OF ITEMS !j:~-Jllll,illllllll 1987 1988 1989 1990 . 1991 1992 n• t75 Tot• 46488.9 nn:­99 . 4 Max• 1573.~ Mean1• 265.65 Mean2• 267 . t7 so­2-40.37 •lllllllllllllmlllllRl•lll I 111 • ·-· SAMPLING FREQUENCY Figure 3.12. Indicator Items: Bi-Daily Counts of Milk Jugs, Egg Cartons, Green Bottles, Chemical Drums, and Beverage Cans -Total Items. n• 667 Tot• 1400 . 3 nn;-91 .9 Max-50 .4 Mean1-2 .09 Mean2· 2 . 28 l~ ~ liilii1liiiiiil1i1li1ii11 so-3 . 76 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL Count of EGG CARTONS n• 667 2 .5 Tot= 785.4 nn:= 82 .4 Max• 15.7 Hean1• 1.17 Hean2• 1.42 IH ~ so-1.82 0.0 PRE/POST-MARPOL 2 .0 0 ;:: i 111 0.0 PRE/POST-MARPOL n• 166 1111111~:~ ! 0 .0 PRE/POST-MARPOL 5.0 1n ­ PRE/POST-MARPOL •lllllllllllmllll•l-1 • -­ Ill•--I SAMPLING FREQUENCY Figure 3.13. Indicator Items: Combined Weekly and Bi-Daily Counts of Milk Jugs, Egg Cartons, Green Bottles, Chemical Drums, and Beverage Cans -All Observations. 30 consistency of occurrence of the indicator items on the beach (beverage cans, 97 % ; milk jugs, 92%, egg cartons, 82%, green bottles, 80%, and 5-gallon pails of chemicals, 59%). Reductions of 50% in numbers per kilometer of beach have been realized in the post-MARPOL era. Note, however, a similar reduction in beverage cans, the source of which is mostly from areas not covered by MARPOL. 3.2 Evaluation of Count Results; Errors Several factors govern the effectiveness of these counts in determining trends in the quantity of debris on the beach. When attempting to isolate those items discarded at sea and affected by MARPOL, the factors multiply. This study, although started long before MARPOL went into effect, targeted items to count that were indicators of origin rather than type ofitem (where one might use a multitude of item categories). Natural items were added as another indicator of origin; certain algae and animals typical of either gulf or bay waters appear in quantity on the beach along with associated litter. The start point of the 11.8-km survey beach is 10 km south of the Aransas Pass entrance to Corpus Christi Bay and 100 km north of the Mansfield Channel (Figure 1.1). Debris, both natural and man-made, is not always evenly distributed along the 11. 8-km of beach. Frequently, debris thins out in quantity going south (the direction in which the survey progresses). The nature of human usage of the beach is changing. More people now visit the beach, especially from the condominiums which are mostly located south of the survey's kilometer 6. When this beach was chosen as a site suitable for surveying, it was sparsely used because of the relatively long distance between the two access roads (the primary access then being by vehicle). As more people used the beach, the city and county effort to clean it of debris intensifiedc Table 3.2 briefly summarizes the usage of the beach. Table 3.2: Summary of Beach Usage and Cleaning Kilometer Jurisdiction Usage 0-0.75 Port Aransas Free parking*; near access road; beach cleaned regularly by city; beach camping. 0.15-4.15 •. Nueces County Parking fee*; one cond~; beach cleaned irregularly; beach camping. 4.75-7.0 Nueces County Concentration of condos; beach cleaned intensively**· 7.0-8.0 Nueces County No condos; beach cleaned regularly. 8.0-10.5 Nueces County Several condos; beach cleaned intensively**. 10.5-12.0 Nueces County No condos; beach cleaned regularly; near access road; beach camping permitted. *Parking regulations and fees have changed several times. **Intensive cleaning using beach-rake equipment starting in 1992. To record the items counted and human usage as a function of distance along the survey beach, the electronic odometer is used to "map" their location. Some problems with the odometer prevented this from being used for all observations. Following the first year (April 1987-May 1988) most surveys were terminated at the 6-km point. Upon resumption of surveys in 1992 for this project, the full distance was covered, except when the debris load was so heavy that it would have taken an inordinately long time to complete. Figure 3.14 shows the frequency of the odometer usage and the total distance covered on all weekly counts. Indicator items counted bi-daily always cover the full 11. 8-km length of the survey beach. 3 .2.1 Accuracy of Counts It is difficult to assess the accuracy of the counts. The author has made the great majority of all observations with the exception of several in 1992 which were done by trained assistants. Counts are more prone to be in error when litter items may be obscured by natural debris, particularly Sargassum. Items which can be counted with minimum error such as milk jugs, bottles and other containers, and those subject to greater errors such as styrofoam pieces and natural debris, are marked in Table 2.1. Errors are on the side of under-counting rather than over-counting. Re-counting is not avoided during the surveys. More accurate counts are made on days when _there is less material to count. In addition, the tendency is to count smaller items on those days of little debris which might get ignored on days when the load is high. 3.2.2 Effect of Beach Cleaning on Counts While beach cleaning is not the only agent of debris removal from the beach, it is the main factor on the survey beach. Other agents include littoral drift, transport by high tides to the dunes, and burial by sand. Another form of beach cleaning over which there is no control is that done by beachgoers who pick up litter and deposit it in the trash receptacles. This is a common activity of people who spend the winter in the condoml.niums. While it is a laudable citizen effort, it does not help the garbage counters. 3.2.3 Distribution of Items Along the Survey Beach Table 3.3 lists the condominiums and other landmarks along the survey beach in distance from the survey' s starting point at Gulf Beach Access Road #1. The numbers in the left column refer to numbered locations in the figures to follow (Figures 3.15 through 3.20). In these diagrams, the counts have been averaged· into 250-m bins so that the distribution of people, natural debris and various litter along the survey beach could be examined. Densities of each bin are in numbers per kilometer to be consistent with the other data presented in this report. Averaging in each bin was done by year, season, and all years from 1987 to 1992. In this section we present the distribution of several different items averaged over the whole study period only. Appendices C and D include seasonal and annual plots for the same categories. In the diagrams, kilometer marks are shown from left-to-right as a function of distance south of 32 ~ E :il ........ c E 1987 1988 1989 . 1990 1991 -1992 n­ 179 ~ o.o DISTANCE OF OBS (KM) 111~1~1 1990 1991 ' 1992 . 1987 1988 1989 1990 1991 1992 n-n = 175 175 -11111111111•11 ••11..lll I 111 . I • ••_.•• SAMPLING FREQUENCY Figure 3 .14. Evaluation of Data: Use of Electronic Odometer, Distances and Times of Surveys. 10.0~: I I 0 : : : : ~~:~~!= = p = = rt 0 1 2 3 4 5 6 7 8 9 10 11 12 n~w;]:f IAUT~OBILES ! (nw·i23l ! i i __I,,~ I .. o:o~r'M~i+~ 0 1 2 3 4 5 6 7 8 9 10 11 12 Count of DOGS (n • 123) 2.0l: : : J~ 1.5 1 1 1 . ..... : : : . ~ 1.0 ~ l l ~:::all.LL.. ! m... "Rri= mm L .lii!...idiiib • .h 0 1 2 3 4 5 6 7 8 9 10 11 12 I D D DD D D Da D D n aD D 1 2 3 "'!5 6 7 B 9 10 11 ~ 14.!5 16 MEAN (ALL YEARS 1987 -1992) Figure 3.15. Distribution Along the Survey Beach: Count of People, Camped People, Automobiles, Camped Cars, Dogs, and People-related Activities. 34 • 5.0 ? 4.0 0 ..... 3.0 ~ 2.0 e ~ 1.0.. Count of CABBAGEHEAO JELLYFISH o.o-e1~~~~~~~~~~~~wa~a1iiaa~~~wu~W""1~~LZU~~~iiil-I 0 1 2 3 4 5 6 7 8 9 10 11 12 Count of DRIFTWOOD (n -12S)!5.0 ;1 41.0 0 :; 3.0 2.0 Ii ~ 1.0.. 0.0 0 1 2 3 4 5 6 7 8 9 10 11 12 count of ~ 41.0L3.0 . ~ 2.0 e ~ 1.0 .. 0.0 . Q 0 1 PEN SHELLS (n • 123) * .. • ·ii l ;­i . mj .• . . i.v 2 3 4 5 6 7 8 9 10 = 11 12 2.5 Iii 2.0 0 ~ 1.5 1.0 e ~ o.~.. o.o Count 0 1 of NATURAL DEBRIS (n • 123) 2 3 4 5 6 7 8 9 10 11 12 I 1 a a aa a a a a a a o aa 2 3 <4 6 a 1 a a 10 u a 14.6 MEAN (ALL YEARS, 1987 -1992) a 18 Figure 3.16. Distribution Along the Survey Beach: Count of Cabbagehead Jellyfish, Portuguese Man-o-war, Driftwood, Pen Shells, and Natural Debris. 2.5 ;;:; 2.0 0 TO 1.5 ~ 1.0 e ~ 0.5.. e 2.0 :.t. ........ 0.0~~~~~~ 0 1 2 3 4 5 6 7 8 9 10 12 11 12 n~ 0 1 2 3 4 5 6 7 8 9 10 I 11 12 1'•:::funt of 'EGG .CART~S ! 'f = 123) . ~u~ 0 1 2 3 4 5 6 7 8 9 10 . I c 11 12 n~ 0 1 2 3 4 5 6 7 8 9 10 I 11 12 I o o oo a a o a o o u oo 1 2 ::i "'!5 s 1 e e 10 11 ~ 14.!5 MEAN ALL YEARS 1987 -1992) o 16 Figure 3.17. Distribution Along the Survey Beach: Count of Plastic Bottles, Green Bottles, One-Gallon Milk Jugs, Egg Cartons, Gloves, and Beverage Cans. 36 I a a aa a a aa a a D aa a 1 2 3 ... 15 8 7 8 SI 10 11 Sii 14.15 18 MEAN (ALL YEARS, 1987 -1992) Figure 3.18. Distribution Along the Survey Beach: Count of Miscellaneous Plastic Pieces, Styrofoam Pieces, and Plastic Bags. 0 1 2 3 4 5 6 7 8 9 10 11 12 I a a aa a a a a a a o aa a 1 2 3 4' !5 6 7 B 9 10 U S 14.!5 16 MEAN (ALL YEARS, 1987 -1992) Figure 3.19. Distribution Along the Survey Beach: Count ofNatural Debris, Plastic Material, Beachgoer Stuff, and People-related Activities. 0 1 2 3 4 5 6 7 8 9 10 11 12 Count Of GALLEY WASTE (n • 123) 2.0 ... ~ 1.!5 ... .. E o.o I D D DD a D Da a a o aa a 1 2 3 .. 15 15 7 BB 10 U ~ 14.15 115 MEAN ALL YEARS 1987 -1992 Figure 3.20. Distribution Along the Survey Beach: Counts Indicative of Particular Sources--Fishing Industry, Offshore Oil Industry, Merchant Marine, Galley Waste, Miscellaneous Stuff, and Beachgoer Stuff. Access Road #1. At the bottom of each group of panels the numbered boxes and vertical lines refer to the location of condominiums and other landmarks listed in Table 3.3. The solid vertical line at km-6 at Gulf Shores Condominium is the dividing line between the actively­cleaned beach to the south and the sporadically-cleaned beach to the north. It is also the terminating point for several GARBGobs, especially in late 1988 and in 1989. Figure 3.15 shows the usage of the beach by people. It clearly illustrates the dominance of the access roads and the condominiums in attracting people to the beach. Natural debris has no such affinity (Figure 3.16), being nearly evenly distributed along the beach. A selection of litter items (Figure 3.17) does show some trends in their geographic distribution. Plastic bottles, green bottles, and milk bottles clearly show a reduction in numbers within the more intensely­cleaned City of Port Aransas area next to Access Road #1 and south of kilometer 6 to Access Road #2. Beverage cans show a distribution mirroring the popular areas of the beach. The three plastic items which are the most numerous items on the beach (miscellaneous plastic pieces, pieces of styrofoam, and plastic bags) show a more even distribution (Figure 3.18). These smaller pieces of plastic are not as efficient! y cleaned by beach crews as are the more obvious items. The larger plastic bags do show a trend in the southern half of the beach. Figure 3.19 compares the combined categories of natural debris, all plastics, those items including plastic and other materials typical of beachgoer items, and the combined activities of people (cars, dogs, etc). The quantity of natural materials shows no trend along the entire beach. Plastics and beachgoer stuff decline in the regularly cleaned half of the beach. People are concentrated around the condos and access roads. Itshould be noted that the scales chosen for these diagrams are consistent for any one item so that the variations are directly comparable. Those presented in the main body of the text are overall means which are lower than say those in Appendix C for selected time periods during the study. Finally, items indicative of particular sources are compared in Figure 3.20. All of these show a lessening in numbers going from north to south, especially from the condominiums and south. This distribution reflects beach-cleaning in that area. It must also be pointed out that while n =123 for these observations they include several observations which stopped at kilometer 6. This also affects the overall mean from that point south. 40 # Distance IDescription Miles Km I I I Table 3.3: Location of Landmarks on the Survey Beach 0 0.0000 1 0.4993 2 1.7370 3 2.5010 4 3.6849 5 3.8047 6 3.9628 7 4.2347 8 5.0125 ­ 9 5.1752 10 5.4213 11 5.7699 12 6.1076 13 6.1342 14 6.3778 15 6.5016 16 7.4466 0.000 0.791 2.754 3.966 5.844 6.033 6.284 6.715 7.949 8.207 8.597 9.150 9.685 9.728 10.114 10.310 11.809 Beach Access Road #1 Port Aransas City Limit Casadel Condominiums Residence La Mirage Condominiums Gulf Shores Condominiums Mustang Towers Condominiums Port Royal Condominiums Sea Gull Condominiums Sandpiper Condominiums Lost Colony Townhomes Walkway to Residence First Private House Second Private House Admiral's Row Mayan Princess Condominiums Beach Access Road #2 3.2.4 Import and Export of Debris on the Study Beach Do the counts done at weekly intervals reveal how much material is washing ashore from the gulf? The ideal condition for the study would be to immediate! y clean the beach following each cou~t so that the next one would assess only material newly washed up in the interval. This cannot be done so we make the assumption that this does happen either by man's action or nature's intervention. During the bi-daily count of five, certain large items are recognizable from count-to-count. On an 8-day observation schedule this is seldom the case. To examine this "import and export" of debris on the beach, Figures 3.21 and 3.22 were constructed. Figure 3.21 shows selected common litter items counted during GARBGobs with import (accumulation) as positive values (# per km) and export (removal) as negative values. In all cases accumulations seldom last for more than two surv,eys and most times a big influx of material "disappears" by the following survey. Unfortunately, the occasional huge import of materials (see plastic bags, for example) reduces the more normal ebb and flow of material to insignificance as illustrated in these diagrams. Nonetheless it would appear that the counts are reasonably representative of new materials coming ashore although it is impossible to put error bars on these data. A similar picture is revealed on a bi-daily surveying schedule as shown in the import and export of the five indicator items counted (Figure 3.22). In each of these figures the net accumulation is given at the right. In all cases except green bottles there is a net accumulation. 3.3 Debris and Litter by Weight Weekly collections ofdebris at three sites on the survey beach (Figure 3.23) are used to evaluate the quantity and frequency of items of litter too small to be counted and natural debris which cannot be counted. Figures 3.24 through 3.27 show the results of the weekly collections of litter and debris by weight per km. The diagrams follow the same form as those described in the introduction to section 3. There are 41 categories of items commonly found during the collections. These are tabulated in Table 2.3. Th~ detailed breakdown of animal species was done to enhance the knowledge of the make-up of floating material as part of a sea­turtle study (Plotkin and Amos, 1989) and was not directly part of this survey. The data are included here for comparison. Figure 3.24 shows the pre-and post-MARPOL distribution--of the vegetable material and includes plastic pieces as the most abundant form of litter collected and PMOW. The most important vegetable material and most abundant of all jetsam is the alga Sargassum, commonly referred to simply as the "weed". From year-to-year the frequency of occurrence and quantity 42 N < 0 ..... .3 ru < 0 ..... ~ (Tl ( 0 ..... x .... c 0 .... 3 e ' .ll .. ;; c 0 .... 3 .ll '.. E ;; ( 0 .... ~ e x. ,. ' 1987 1988 1989 1990 1991 1992 n• 174 Tot• 7.5 2.5 2.0 1.5 1. 0 0.5 o.o -0 . 5 -1.0 -1.5 -2 . 0 -2 . 5 1987 1988 1989 1990 1992 1987 1988 1989 1990 1991 1992 Import/Export of GREEN BOTTLES (MEXICAN) 1987 1988 1989 1990 1991 1992 Tot• 5.4 n• 174 Tot• . 2 lllllll Wllllll 111111111 111111111111111111111 11111111111111111111111111111111 I I II I 111 I lllllllll lllllllllllllllllllllUlllllllllll 111111111111111 SAMPLING FREQUENCY Figure 3.21. Import and Export of Debris: Common Litter Items Counted During GARBGobs. :Ji '.. E e .. :Ji ' E ' ~ ... ( ­ 0 ~ E '.. :Ji ONE-GALLON MILK JUGS 1987 1988 1989 1990 1991 1992 n­501 Tot­. 1 n­501 Tot­1. 8 Import/Export of GREEN BOTTLES 1987 1988 1989 1990 1991 1992 n• 501 Tot• -3.9 Import/Export of CHEMICAL DRUMS. PAILS 10 . 0~~~~~~~~~~~~~~~~~~~~~~~~ 7.5 5 . 0 2.5 o.o~~~~~~Ki.i!!l~B+.~~*-&.~~~~~~~~~~~ff -2.5 -5.0 -7.5 -10.0..&;i;i;i;l~~~~i;i;i;i;i;i;ill~i;i;i;i;i;i;ill~~~~~~~~~~~~~~~~ 1989 1990 1991 1992 BEVERAGE CANS 1987 1988 1989 1990 1991 1992 n• 501 Tot• 5.3 n• 334 Tot• .3 5.0 4.0 3 . 0 2.0 1.0 0.0 -1.0 -2.0 -3.0 -4.0 n­501 Tot• .5 -_.,... I -­• ·­I • •SAMPLING FREQUENCY Figure 3.22. Import and Export of Debris: Five Indicator Items Counted on Bi-Daily Survey. 44 97o 15'W 97° 10 ·w 97° 5'W 97° 0. w 27° 55'N~~~~~~~~i:=:::i:=:=~;:::c=:=~~~27° 55 'N .~~~~~~~ 97o 15'W 97° 10 ·w 97° 5'W 97° 0. w Figure 3.23. Location of Weekly Collection Sites on Mustang Island showing relation to Beach and Garbage (B & G) Survey transect. 1) UT Marine Science Institute 2) Port Aransas 3) Aransas Pass n-119 n-59 6.0 Tot-473 _9 0 0 nT%-39 4 4 .0 ... ~ Max-201 .6 Mean1-3 98 2.0 ~ Mean2-10 08 so-23.29 Ul 0 .0 PRE/POST~MARPOL n-119 2.0 ­ (T) Tot= 86677 . 2 nTX= 78.9 1.5 ~ ? ~ Max~ 8151. 5 1.0 E Meanl• 728.38 0.5 Mean2= 922 .09 SD= 1448 . 07 0.0 PRE/POST-MARPOL n• 119 2 . 0;; Tot• 1187 . 6 nn:~ 81.5 Max• 150.5 Mean1• 9.99 Mean2• 12 . 24 LJ~:~ ; so-22 .68 PRE/POST-MARPOL n-119 2.0 ­ Tot• 8739 .5 1.5 ~ nn-60.5 .... Max• 3757 .1 Mean1• 73.44 Mean2• 121.38 lJl:: i N so-400.91 0.0 PRE/POST-MAAPOL n-119 n• 69 Tot• 614.2 nn-18.4 Max• 363.6 Mean1-5 . 16 Mean2-27 . 92 1ij111111111111E r1 so-34 .25 PRE/POST-MARPOL n• 119 Tot• 1693. 4 ~2.0~ nn-94.1 Max• 190.8 ­Mean1• 14 .23 Mean2• 15. 12 11111:·: i so-28.56 o.o PRE/POST-MARPOL Figure 3.24. Results of Weekly Collections by Weight per Kilometer: Algae, Sargassum, Seagrass, Water Hyacinth, Portuguese Man-o-war, Plastic, Woody Vegetation, and Other Vegetation. 46 n-119 Ll 6 . D;:; Tot-3664 . 6 nn::-57.9 4.0 ~ Max-846 .5 -:: ~ Mean 1-30 . 79 2 .0 ~ Mean2-53 . 11 ' ~ so-107 .04 0 .0 PRE/POST-MARPOL -69 2.0 ;:; 1.5 ~ 1. 0 ~ Ul: : ~ • PRE/POST-MARPOL 11111111111111111 111m111111u1111u10 SAMPLING FREQUENCY Figure 3.24. (cont.) Results of Weekly Collections by Weight per Kilometer: Algae, Sargassum, Seagrass, Water Hyacinth, Portuguese Man-o-war, Plastic, Woody Vegetation, and Other Vegetation. 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL n• 119 Tot• 240.3 &.J2.S nn;-47 .o Max• 64.5 Mean1• 2 .01 Mean2-4.29 i·~:~•iiil,iiiitllllllllll -r~i SO• B. 65 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL n• 119 5.0-;; Tot• 24 .7 I 4.0 ~ nlll:• 6 . 7 Max• 7 .4 Mean1• . 20 Mean2• 3 . 09 ;:: ~ i·~:~iliiiiiiilll!llllllilltlllll lJSO• .96 0.0 o.o 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL 11111111 ElllllJI 11111111111m11111n11 SAMPLING FREQUENCY Figure 3.25. Results of Weekly Collections by Weight per Kilometer: Animals Collected. 48 1987 1988 1989 1990 1991 1992 n-119 Tot• 35.6 nTX• -43 .6 Max• 7 .6 Mean1-. 29 Mean2-.68 so-. 97 n• 119 Tot• 3.1 nTX• 18.4 Max• 1.2 Mean1• 2 .65 Mean2• .14 SO• .13 111111111111111 SAMPLING FREQUENCY PRE/POST-MARPOL LJ4.0 ~ -~:~; PRE/POST-MARPOL 4.0(\j I 3.0 ~ : : i • o.o PRE/POST-MARPOL Figure 3.25. (cont) Results of Weekly Collections by Weight per Kilometer: Animals Collected. 49 n-119 Tot• 38.B nn:-32 . 7 Ma x­Mean1• . 32 Mean2• . 99 i~ . ~ lliiflllil11li11~1iiiiii I~iE~iiii~iil I so-.97 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL n-119 2.0 ­ 0 Tot= 74.2 1 .5 ~ nn= 16.9 Maxz 52. 7 Mean1• .62 Mean22 3. 71 ; : i "'; SO= 4 . 97 0 .0 PRE/POST-MARPOL n• 119 69 8.0 ~ Tote 64.0 nn:• 94 .0 Max• 35.2 Meant• .53 i~ :~&•F~ATH~Rs···· ,_J*r1:.. 1 Me11n2• .64 so-3 . 23 Ull~:~ t 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL 1111111111111u11 nu11nn•111n111 SAMPLING FREQUENCY Figure 3.25. (cont.) Results of Weekly Collections by Weight per Kilometer: Animals Collected. 50 n-119 10 . 0r\j Tot-7 2 I nn:-6 7 Max-1 2 Mean1-6 . 10 Mean2-90 so-. 25 111~:~ ~ PRE/POST-MARPOL n-119 10 . 0;:; Tot= 58.6 .' nTX= 36.1 7 .5 ~ ~ Max• 17 .5 Mean1= . 49 Mean2= 1.36 SO= 1.97 : : ~ PRE/POST-MARPOL n= 119 2 . 5;; Tot• 12.0 nTX= 5 .0 Max• 6 .6 Mezm1• . 10 Mean2• 2 . 01 IJn; .' so- .64 0 .0 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL n• 119 2.0;; Tot• 13 .7 I ( 1.5 ~ nTX- !51.2 Max- i.7 Means-• u Mean2-. 22 ~ ~:~iill!fii:ililllllllll ::: i so-.2!5 • 0.0 0.0 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL n-119 2.0 ­Tot• 102. 7 nn:- 1 .s 1.5 ~ Max-'43.0 Meant-.86 Mean2-11.41 so-'4 .94 Lll::: ; 0 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL n• 119 2.0 ­Tot• 107 .8 0 1.5 ~ nTX• '46.2 Max• 23.9 Mean1• .90 Mean2• 1.96 i~:~ illiliiii~iil1iillllllll!1Illll ::: i so-2. 79 o.o o.o 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL 1111111111111111 lllmlllllllllllD SAMPLING FREQUENCY Figure 3.26. Results of Weekly Collections by Weight per Kilometer: Man-made Litter. 51 n-119 Tot-1693 4 ~20~ nT~-94 .1 Max-190. 8 Meant-14 23 Mean2-15 12 BJI:: ~ so-28 .56 0 .0 PRE/POST-MARPOL n-119 2 .0 Tot= 132.1 1.5 ~ nn:= 82.3 Max• 15.5 Mean1• 1.11 Mean2• 1.34 ::: i 0 SO= 2.41 0.0 PRE/POST-MARPOL n• 119 2.0 ­ Tot• 144.9 nn:= 21.8 Max• 32.8 Mean1• 1. 21 ::: j 0 Mean2• 5 . 57 so-4.29 0.0 PRE/POST-MARPOL n-119 2.0 ­ Tot-91.2 nn:-8 .4 1.5 ~ Max• !53.!5 Mean1• •76 Mean2• 9.12 ::: i 0 so-!5.07 0.0 PRE/POST-MARPOL n• 119 5.0 ­ Tot• 369.1 nT!I:• 61 . 3 ::: i Max• 91 .2 Mean1• 3.10 Mean2• 5.05 i·~:~•iiillilllillllll!lllllll Ul~-~ ~ so-11 . 48 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL n• 119 2.0_ 0 Tot• 138.1 1.5 ~ nT!I:• 36.9 ~ Max• 29.4 Mean1• 1.16 Mean2• 3.13 ::: i so-4.26 0.0 PRE/POST-MARPOL - 11111111 IUllUll 111111111111111• SAMPLING FREQUENCY Figure 3.26. (cont.) Results of Weekly Collections by Weight per Kilometer: Man-made Litter. 52 n-119 4.0 ­ Tot-2835 .5 nu:-90 . 7 3 .0 8 )( Max-588.6 Mean1-23 . 82 Mean2-26 .25 ::i so-83 . 75 0 .0 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL n-119 n-69 2 .5 Tot= 18259 . 8 2 . 0 :::, nT%= 70 .5 Max• 5995 .4 Mean1= 153.44 : :~ : Mean2a 217 . 37 i~·~litiillilliill·•:··············· '111111 ······ ·Ul n:; ···• 1 so-632.11 : ? ~~ 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL n• 119 10.00 Tot• 698.0 8.0 ~ nT%• 67 .2 - Max• 144.2 Mean1 • 5.86 : :~ ~ Mean2• 8.72 2.0 i~:~11c;:5t·. •••· ·•·····•••·· ·•11J..)l 11 .i••. so-14 . 90 Ul •1 ? 0.0 0.0 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL n-119 Tot-365.0 L.J4.0­ nn-31.0 Max-99.3 Mean1-3.06 Me11n2-9.86 i·~:~iiliiililiiilillil ll!ltllll -:.:; so-11.85 0.0 . 0.0 1987 1988 1989 1990 1991 1992 PRE/POST-MARPOL ....... •1111111111 SAMPLING FREQUENCY Figure 3.27. Results of Weekly Collections by Weight per Kilometer: Unknown Origin. 54 of weed on the beach varies considerably. Sometimes it is so thick that beach authorities mechanically remove it by grading the beach. There is an association at sea between weed and "trash" in the windrows and patches and, consequently, should be an association when the material is washed ashore. Sargassum was abundant in 1991 and 1992 but less-so in 1987-1988. At the same time the plastic decreased, contrary to expectations, but the PMOW increased. Seagrasses, which are only found in the bays, also decreased, but the terrestrial plant water hyacinth, which has its origin in rivers increased dramatically. Woody vegetation, also riverborne, and other vegetation, which may also come from rivers similarly increased. Figure 3.25 illustrates the variation in the animals collected of which PMOW, cabbagehead, and sea pens are the most important. All increased post-MARPOL reflecting the general increase in natural debris in this period. Of the man-made litter collected (Figure 3.26), some items like light bulbs and milk jug are found singly in the survey areas and do not really count statistically in the analysis. Of the smaller items counted, the pre-and post-MARPOL. quantities show variability, but the two major items, plastic pieces and styrof oam, have decreased. Items whose origin is not clear are illustrated in Figure 3.27. Pelagic tar has decreased on the beach. This has· been noticeable not only by the measurements and estimates made by the author, but also by the beach-going public at large. A huge influx of driftwood in 1991 accounts for the post-MARPOL increase. This occurred along much of the Texas coast. 3 .4 Ranking of Debris and Litter by Quantity and Weight This section shows the relative importance of various items of debris and litter ranked by quantity and weight and frequency of occurrence on the Mustang Island survey beach. The section is divided into two parts; the "macro-litter" and natural debris as counted during GARBGobs, and the "micro-litter" and uncountable natural debris as weighed during the weekly collections. 3.4.1 Macro-Litter and Debris (by Quantity) Each of the tables includes the "Top 50" out of the 73 categories of items which were deemed rankable. In this section, cars, people, dogs, and horses were included for comparison of numbers with other prominent "visitors" to the beach. Table 3.4 ranks the items by total counted. Also shown are the frequency of occurrence and the maximum number counted (per/km) on any one survey. A grand total of 394,429 items was counted during the 175 observations used in this analysis. Styrofoam pieces top the list with 102,520. In the top ten (excluding people), three natural debris items (PMOW, driftwood and cabbageheadjellyfish) occur and the rest are plastic items. It should be noted that most driftwood on this beach is the result of man's activities in_clearing land or discarding lumber pieces. Ranked by the mean number of items per kilometer of beach (Table 3.5), the order changes little. Table 3.5 also lists the ranking pre-and post-MARPOL. The order changes little, but the post-MARPOL density is less for most of the litter but greater for driftwood and people visiting the beach. The number of observations was 75 pre-MARPOL and 100 post-MARPOL. Table 3.4: Macro-Litter and Natural Debris Ranked by Total Counted -All Observations Description of Item Total Freq 1 Styrofoam pieces 102,520 99.4 2 Portuguese man-o-war 50,515 69.0 3 Plastic bags 49,031 99.4 4 Miscellaneous plastic piece 31,503 98.3 Driftwood 25,819 98.3 6 Plastic bottles 17,831 98.9 7 People 15,160 98.3 8 Cabbagehead jellyfish 10,659 62.1 9 Rope and hawsers 8,406 96.6 Lids (plastic) 7,818 96.0 11 Disposable drink cups 7,208 99.4 12 Glass bottles 7,184 93.7 13 Aluminum beverage cans 6,399 100.0 14 Pen shells 4,237 66.1 Plastic sheeting 4,059 92.0 16 Paper products 4,013 96.6 17 One-gallon milk jugs 3,879 90.8 18 Automobiles 3,717 97.7 19 Egg cartons 3,505 90.2 Green bottles (mexican) 2,869 81.0 21 Gloves 2,399 87.4 22 Cans (not beverage cans) 2,358 88.5 23 Six-pack rings 2,279 86.2 24 Lightbulbs 1,768 82.2 Light sticks 1,702 66.1 26 Foam (not styrofoam) 1,539 85.6 27 Shoes 1,229 80.5 28 Cardboard cartons 1,203 86.2 29 Fruit 1,197 82.8 Camped people 1,137 66.7 31 Plastic strapping 1,090 56.3 32 Dead fish 1,074 77.6 33 Produce sacks 1,016 85.l 34 Dead crabs 888 66.1 Camped cars 797 72.4 36 Balloons 722 68.4 37 Outboard motor oil 682 55.2 38 Fishing and seismic floats 601 73.6 39 Sea beans 540 10.9 5-Gal plastic pails 524 60.3 41 Fluorescent tubes 519 56.3 42 Vegetables 499 62.1 43 Cloth and clothing 487 70.7 44 Spent fireworks 485 12.1 Fishing line 481 64.9 46 Miscellaneous metal pieces 407 73.0 47 Coconuts 353 37.9 48 Horses 340 21.3 49 Dogs 323 65.S so Disposabie lighters 320 62.1 Total 394,429 100.0 Max #/Km 993.42 1,399.75 1 179.88 243.69 353.48 140.73 79.81 136.02 37.66 40.49 104. 77 39.78 34.76 62.85 21.31 34.22 50.46 23.38 15.72 27.83 18.94 11.91 26.12 12.55 36.85 5.67 10.36 4.45 7.94 20.85 8.60 12. 68 . 5.84 11.47 12.91 7.08 10.85 3.29 21.54 6.97 5.19 4.28 3.80 27.15 4.69 2.48 3.65 2.36• 1.67 2.34 Table 3.5: Macro-Litter and Debris Ranked by Mean Number Per Kilometer All Obs Pre-MARPOL Post-MARPOL 1 2 3 4 Item Styrofoam pieces Portuguese man-o-war Plastic bagsMisc. Plastic pcs.Driftwood Mean/km 73.12 35.17 35.07 19.19 16.22 Item -Styrofoam pieces Plastic bagsPortuguese man-o-war Miscellaneous plastic pcs. Driftwood Mean/km86.08 51.64 51.35 16.30 15.43 Item Styrofoam pieces Portuguese man-o-war PlasUc bagsMiscellaneous plastic pcs~ Driftwood mean/km63.54 23.20 22.80 21.34 16.79 6 Plastic bottles 12.32 Plastic bottles 12.00 Plastic bottles 12.56 V\ .....J 7 8 9 11 12 13 14 16 17 18 19 21 22 23 24 26 27 28 29 PeopleCabbagehead jellyfish Rope and hawsers Lids (plastic) Glass bottles Disposable drink cups Aluninun beverage cans Pen shells One-gallon milk jugsPaper products Plastic sheetingEgg cartons Automobiles Green bottles (mexican)Cans (not beverage cans) Six-pack rings Gloves Light sticks LightbulbsFoam (not styrofoam) Ca~ peoplePlastic strappingShoes 8.44 6.34 5.64 5.25 5.08 5.03 4.04 2.87 2.83 2.39 2.34 2.32 2.20 1.93 1.67 1.62 1.53 1.35 1.30 1.00 0.00 0.83 0.81 Cabbagehead jellyfishDisposable drink cups Lids (plastic)PeopleRope and hawsers Glass bottles Pen shells Plastic sheeting Aluninun beverage cans One-gallon milk jugs Egg cartons Six-pack rings Lf ghf sticks Automobiles Cans (not beverage cans) Gloves G.reen bottles (mexican)Paper products Lf ghtbulbsFoam (not styrofoam) Cardboard cartons Shoes Dead crabs 7.84 7.04' 6.89 6.80 6.36 5.91 5.42 4.43 4.22 3.33 2.99 2.51 2.19 2.08 1.93 1.79 1.73 1.n 1.47 1.08 1.00 0.97 0.91 PeopleCabbagehead jellyfishRope and hawsers Glass bottles Lf ds (pl as tic)Aluninun beverage cans Disposable drink cups Paper products One-gallon milk jugs Automobiles Green bottles (mexican)Egg cartons Cans (not beverage cans) Gloves Lf ghtbulbsCaq:>ed people Pen shells Six-pack rings Foam (not styrofoam)Plastic strappingPlastic sheetingCaq:>ed cars Dead fish 9.65 5.23 5.11 4.46 4.03 3.91 3.55 2.89 2.46 2.28 2.08 1.83 1.48 1.35 1.17 1.03 0.99 0.97 0.94 0.93 0.79 0.78 0.74 Cardboard cartons 0.80 Fruit 0.85 Fruit 0.74 31 32 33 Fruit Produce sacks Dead fish 0.79 0.65 0.65 Plastic strappingCaq>ed people Produce sacks 0.69 0.63 0.54 Produce sacks Lf ght sticks Shoes 0.74 0.73 0.69 34 Ca~ cars 0.00 Dead fish 0.53 Cardboard cartons 0.65 Dead crabs 0.54 Bal loons 0.51 outboard motor oil 0.59 36 37 38 39 41 42 43 44 t.6 47 48 49 Bal loons Outboard motor oil · Fishing and seismic floats 5-Gal plastic pailsFluorescent tubes Fishing line VegetablesSea beans Cloth and clothingSpent fireworks Miscellaneous metal pieces Coconuts Disposable lighters ·· Dogs Toys 0.53 0.48 0.42 0.39 0.37 0.34 0.34 0.32 0.31 0.28 0.27 0.25 0.22 o.oo 0.19 S·Gal plastic pails F i sh ing l i ne Fishing/seismic floats Cloth and clothingVegetablesFluorescent tubes Misc. Metal piecesCamped cars outboard motor oil Disposable lightersWr.fte-protect rings Tubes of grease ToysReels (cable; line)Dogs a.so 0.46 0.43 0.39 0.39 0.38 0.37 0.35 0.34 0.30 0.21 0.17 0.16 0.16 0.15 Sea beans Bal loons Spent fireworks Fishing and seismic floats Fluorescent tubes Coconuts VegetablesS·Gal plastic pailsDead crabs F i sh ing l i ne Cloth and clothingDogs Dead bird ToysMiscellaneous metal pieces 0.54 0.54 0.44 0.42 0.37 0.34 0.31 0.30 0.26 0.25 0.25 0.24 0.23 0.20 0.19 Table 3.6: Macro-Litter and Debris Ranked by Frequency All Obs Pre-MARPOL Post-MARPOL Item 1 Al1.111in1.111 beverage cans 2 Plastf c bags 3 Styrofoam pieces 4 Disposable drink cups Plastic bottles 6 People 7 Miscellaneous plastic pcs.8 Driftwood 9 Automobiles Freq100.0 99.4 99.4 99.4 98.9 98.3 98.3 98.3 97.7 Item Al1.111in1.111 beverage cans Styrofoam pieces Plastic sheetingDisposable ·drink cups Plastic bottles Paper products Plastic bagsMiscellaneous plastic pcs.Driftwood Freq100.0 100.0 100.0 100.0 100.0 '98.6 98.6 98.6 98.6 Item Al1.111in1.111 beverage cans Plastic bagsPeople Styrofoam pieces Disposable drink cups Automobiles Miscellaneous plastic pcs. Plastic bottles Driftwood Freq100.0 100.0 99.0 99.0 99.0 98.0 98.0 98.0 98.0 U\ 00 Paper products 11 Rope and hawsers 12 Lids (plastic)13 Glass bottles 14 Plastic sheetingOne-gallon milk jugs 16 Egg cartons 17 Cans (not beverage cans) 18 Gloves 19 Six-pack rings Cardboard cartons 21 Foam (not styrofoam) 22 Produce sacks 23 Fruit 96.6 96.6 96.0 93.7 92.0 90.8 90.2 88.5 87.4 86.2 86.2 85.6 85.1 82.8 PeopleAutomobiles Lfds (plastic)Egg cartons Rope and hawsers Glass bottles One-gallon milk jugs Gloves Cans (not beverage cans) Cardboard cartons Six-pack rfngs Foam (not styrofoam) LightbulbsFruit 97.3 97.3 97.3 95.9 95.9 94.6 94.6 93.2 93.2 93.2 90.5 89.2 87.8 86.5 Rope and hawsers Lids (plastic)Paper products Glass bottles One-gallon milk jugs Egg cartons Produce sacks Plastic sheetingCans (not beverage cans) Gloves Six-pack rings Foam (not styrofoam) Cardboard cartons Fruit 97.0 95.0 95.0 93.0 88.0 86.0 86.0 86.0 85.0 83.0 83.0 83.0 81.0 80.0 24 LightbulbsGreen bottles (mexican) 26 Shoes 27 Dead fish 28 Fishing and seismic floats 29 Miscellaneous metal pieces Ca~ cars 82.2 81.0 80.5 77.6 73.6 73.0n.4 Green bottles (mexican)Miscellaneous metal pieces Produce sacks Pen shells Shoes Cloth and clothingDead fish 85.1 85.1 83.8 83.8 82.4 82.4 81.1 Shoes Green bottles (mexican)LightbulbsPlastic strappingDead fish Ca~ cars Balloons 79.0 78.0 78.0 76.0 75.0 73.0 73.0 31 Cloth and clothing32 Portuguese man-o-war . 33 Balloons 34 Ca~ peopleLight sticks 36 Pen shells 37 Dead crabs 38 Dogs39 Fishing lfne Vegetables41 Cabbagehead jellyfish 42 Disposable lighters43 5-Gal plastic pails44 Plastic strappingFluorescent tubes 46 outboard motor oil 47 Toys48 Tubes of grease 49 Fishing nets Dead bird 70.7 69.0 68.4 66.7 66.1 66.1 66.1 65.5 64.9 62.1 62.1 62.1 60.3 56.3 56.3 55.2 46.6 44.8 42.5 38.5 Dead crabs Ff shfng lfne Fishing and seismic floats Caq>ed cars Lf ght sticks Portuguese man-o-war Cafl1)ed peopl•Vegetables5-Gal plastic pailsDisposable lightersFluorescent tubes Bal loons Cabbagehead jellyfish DogsTubes of grease Reels (cable;ffshing line)ToysWrite-protect rings outboard motor of l Fishing nets 79.7 n.o n.o 71.6 71.6 71.6 70.3 67.6 66.2 64.9 63.5 62.2 62.2 56.8 52.7 51.4 45.9 44.6 44.6 40.5 DogsFishing and seismic floats Portuguese man-o-war Ca~ peopleMiscellaneous metal pieces outboard motor oil Lf ght sticks Cloth and clothingCabbagehead jellyfishDisposable lightersVegetables 5-Gal plastic pailsFishing line Dead crabs Pen shells Dead bird Coconuts Fluorescent tubes ToysFishing nets 72.0 71.0 67.0 64.0 64.0 63.0 62.0 62.0 62.0 60.0 58.0 56.0 56.0 56.0 53.0 53.0 52.0 51.0 47.0 44.0 Table 3.6 ranks the data by frequency of occurrence (expressed as a percentage) on the beach. The ranking order changes considerably as all but driftwood in the natural debris category drop out of the top-30 reflecting the seasonality of these beachings compared to the more constant input of man-made litter. Note that pre-MARPOL, several items were encountered on every survey but post-MARPOL only beverage cans are 100% present and these ~ are almost always left by beachgoers. Not only has the density of litter decreased but so has its frequency since MARPOL. Some litter items (e.g. plastic bags) have increased in frequency. The percentage of plastics in the total of man-made items has changed very little as illustrated in Table 3.7. 3.4.2 Micro-Litter and Uncountable Debris (by Weight) Table 3.8 ranks the micro-litter and other debris by total weight in the 118 observations made both before and after MARPOL. Of the eleven man-made items commonly found, only plastic (pieces) appears in the top-10. Over 50 kg of plastic fragments were collected. Compare this to .the 2,600 kg of Sargassum weighed (or in exceptionally heavy weed days, a measured section was weighed and the total weight then estimated by blocking). Comparing the extrapolated weights per kilometer ranked in Table 3.9, plastic pieces dropped from fourth pre-MARPOL to eighth post-MARPOL. 1991-1992 saw heavy beachings of Sargassum, driftwood, and terrestrial vegetation, yet the overall concentration of plastic pieces was down from the 1987-1988 period of the pre-MARPOL measurements. Table 3.7: Percentage of Plastic Among the Micro-Litter All Obs Pre-MARPOL Post-MARPOL n=175 n=75 n=lOO Total # % Total # % Total # % Plastic items 245,662 87.1 124,031 87.4 121,233 86.6 Other items 32,830 12.9 17,748 12.5 18,732 13.4 Natural items 94,298 53,835 40,463 Table 3.8: Micro-Litter and Uncountable Debris Ranked By Total Weighed -All Observations 1 2 Description of Item Sargassum Wood Total(kg) v 2600. 32 w 547.80 Freq 79.7 71.2 Max(kg) 244.545 179.863 3 Water hyacinth •./ 262.19 61.0 112. 715 4 Mollusks A 155.27 87.3 39.432 Woody vegetation v' 109.94 58.5 25.395 6 7 Tar Plastic M )(. 85.07 so.so 91.5 94.9 17.659 5.724 ~ 8 9 11 12 13 14 16 17 18 19 Other vegetation Cabbagehead Seagrass Rocks Portuguese man-o-war Algae Sand dollar Rope Miscellaneous Leptogorgia Sea bean Plastic bottle " 47.61 A. 41.49 v 35.63 M 20.94 A 18.43 "' 14.22 (\ 12.73 " 11.08 ~ 10.95 A 7.21 v 5.05 ~ 4.35 39.0 19.S 82.2 67.8 18.6 39.8 65.3 61.9 31.4 47.5 33.1 22.0 34.591 17.600 4.517 4.326 10.908 6.048 0.919 2.736 2.979 1.936 1. 557 . 0.986 \~ . ~ o,\p (),J 0,s ~·~ t~~ ~3% ~J\-;S q,1,­~ '(.A ~ /;!> ~ ~ :t-3.-:ss lf.)lo 1..-1 l. 3_"(.,3 ~ ~. e< ')(. A 4.14 3.97 3.87 37.3 83.1 38.1 0.882 0.465 0.879 ~e.~s ~~ ~C~, ' "I­>'­A 3.23 3.08 2.74 2.23 46.6 7.6 8.5 16.9 o. 718 1.292 1.607 1.583 ~ \M-iN ?A-~,~ (()~.,t) l i-\,,-0 27 28 29 Feathers · Paper Velella Other invertebrates r'.\ ~ A A 1.92 1. 76 1.37 1.17 84.7 36.4 5.9 33.1 1.058 0.527 1.146 0.180 y... \f..>~ 91. n~ S1n-~ \3-4-4' 31 crabs A 1.07 44.1 0.229 32 Vegetables v 0.99 16.1 0.252 33 Anemones A 0.74 6.8 0.224 34 36 Egg Cigarette Starfish A ~ A 0.64 0.41 0.36 7.6 51. 7 6.8 0.354 0.051 0.249 37 Cup y.. 0.36 5.1 0.199 38 39 41 Light bulb Mangrove seed Sea pens Insects '/. 0.22 v 0.21 ft 0. 20 A o.o9 6.8 11.9 12.7 18.6 ·O. 037 0.070 0.087 0.036 5e~?J.~ ~~.~ Table 3.9: Micro-Litter and Unoountable Debris Ranked By Weight per Kilometer All Obs Pre-MARPOL Post-MARPOL 1 Item Sargassum kg/km 734.55 Item Sargassum kg/km 322.24 Item Sargassum kg/km 1,027.34 2 Wood 154.74 Wood 33.83 Wood 240.61 3 Water hyacinth 74.06 Tar 26.08 Water hyacinth 120.53 4 Mollusks Woody vegetation 43.86 31.06 Seagrass Plastic. 17.37 17.11 Mollusks Woody vegetation 64.78 52.56 6 Tar 24.03 Mollusks 14.40 Tar 22.58 7 Plastic 14.35 Water hyacinth 8.63 Other vegetation 18.97 8 9 Other vegetation Cabbagehead Seagrass 13.45 11.72 10.07 Other vegetation Miscellaneous Cabbagehead 5.68 3.61 3.36 Cabbagehead Plastic Rocks 17.66 12.40 8.35 11 Rocks 5.92 Rocks 2.49 Portuguese man-o-war 7.33 12 13 Portuguese man-o-war Algae 5.21 4.02 Leptogorgia Portuguese man-o-war 2.47 2.21 Algae Seagrass 5.87 4.88 14 Sand dollar 3.60 Sand dollar 1.81 Sand dollar 4.86 16 Rope Miscellaneous 3.13 3.09 Plastic bottle Aluminium 1.48 1.48 Rope Miscellaneous 4.43 2.73 0\ I>-" 17 18 19 21 22 23 24 26 Leptogorgia Sea bean Plastic bottle Glass Styrofoam Diopatra Aluminium Cloth Milk jug Fish 2.04 1.43 1.23 1.17 1.12 1.09 0.91 0.87 o. 77 0.63 Styrofoam Algae Milk jug Rope Glass Fish Diopatra Woody vegetation Other invertebrates Anemones 1.42 1.40 1.38 1.29 1.19 1.14 1.06 o. 77 0.46 0.42 Sea bean Leptogorgia Cloth Glass Oiopatra Plastic bottle Styrofoam Feathers Paper Velella 2.37 1. 73 1.34 1.16 1.12 1.05 0.91 0.75 0.62 0.56 27 Feathers 0.54 crabs 0.37 Aluminium 0.51 28 29 Paper Velella a.so 0.39 Paper Feathers 0.32 0.25 Milk jug Vegetables 0.34 0.34 Other invertebrates 0.33 Cloth 0.21 Fish 0.26 31 32 33 34 36 37 crabs Vegetables Anemones Egg Cigarette Starfish Cup 0.30 0.28 0.21 0.18 0.12 0.10 0.10 Cup Vegetables Egg Velella Cigarette Sea bean Mangrove seed 0.21 0.20 0.16 0.15 0.11 0.10 0.06 Crabs Other invertebrates Egg Starfish Cigarette Sea pens Light bulb 0.25 0.24 0.19 0.15 0.12 0.07 0.07 38 ~9 Light bulb Mangrove seed 0.06 0.06 Light bulb Sea pens o.os 0.04 Anemones Mangrove seed 0.06 0.06 41 Sea pens Insects 0.06 0.03 Starfish Insects 0.03 0.03 Insects Cup 0.03 0.03 Table 3.10~crcf~Liffer and Uncoiiiitable Debris Ranked By Frequency All Obs Pre-MARPOL Post-MARPOL 1 Item Plastic Freq 94.9 Item Plastic Freq 98.0 Item Tar Freq 92.8 2 Tar 91.5 Tar 89.8 Plastic 92.8 3 4 Mollusks Feathers 87.3 84.7 Seagrass Wood 83.7 81.6 Rocks Mollusks 91.3 91.3 6 7 8 9 Styrofoam Seagrass Sargassum Wood Rocks 83.1 82.2 79.7 71.2 67.8 Styrofoam Feathers Mollusks Sargas~um Cigarette 81.6 81.6 81.6 79.6 53.1 Feathers Styrofoam Woody vegetation Seagrass Sargassum 87.0 84.1 81.2 81.2 79.7 Sand dollar 65.3 Other vegetation 51.0 Sand dollar 78.3 0\ N 11 12 13 14 16 17 18 19 21 Rope Water hyacinth Woody vegetation Cigarette Leptogorgia Aluminium Crabs Algae Other vegetation Diopatra Glass 61.9 6.1.0 58.5 51. 7 47.5 46.6 44.1 39.8 39.0 38.1 37.3 Water hyacinth Rope Leptogorgia Sand dollar Aluminium Other invertebrates Diopatra Rocks Algae Glass Crabs 51.0 49.0 49.0 46.9 40.8 40.8 36.7 34.7 28.6 26.5 26.5 Rope Water hyacinth Wood Crabs Aluminium Cigarette Sea bean Algae Leptogorgia Paper Glass 71.0 68.1 63.8 56.5 50.7 50.7 49.3 47.8 46.4 44.9 44.9 22 23 Paper Other invertebrates 36.4 33.1 Woody vegetatio~ Vegetables 26.5 24.5 Diopatra Miscellaneous 39.1 37.7 24 Sea bean Miscellaneous 33.1 31.4 Paper Plastic bottle 24.5 24.5 Other vegetation Other invertebrates 30.4 27.5 26 27 28 29 Plastic bottle Cabbagehead Insects Portuguese man-o-war Fish 22.0 19.5 18.6 18.6 16.9 Mangrove seed Miscellaneous Portuguese man-o-war . Milk jug Fish 24.5 22.4 16.3 12.2 10.2 Cabbagehead Insects Fish Plastic bottle Portuguese man-o-war 27.5 26.1 21. 7 20.3 20.3 31 Vegetables 16.1 Anemones 10.2 Sea pens 14.5 32 33 34 Sea pens Mangrove Milk jug seed 12.7 11.9 8.5 Sea pens Velella Sea bean 10.2 10.2 10.2 Vegetables Cloth Starfish 10.1 10.1 8.7 36 37 Egg Cloth Light bulb 7.6 7.6 6.8 Egg Cup Insects 8.2 8.2 8.2 Egg Light bulb Milk jug 7.2 7.2 5.8 3'8 Starfish 6.8 Cabbagehead 8.2 Anemones 4.3 39 Anemones 6.8 Light bulb 6.1 Cup 2.9 Velella 5.9 Cloth 4.1 Velella 2.9 41 Cup 5.1 Starfish 4.1 Mangrove seed 2.9 .• How did the frequency of beaching of micro-litter compare with the larger material? Table 3.10 shows that plastic pieces were consistently the most frequently found material among the beach-wrack followed closely by pelagic tar. Styrofoam pieces were the fifth most commonly occurring of the 41 items identified in the weekly collections of beach debris. Plastic pieces were found less frequently after MARPOL but styrofoam was more frequent. These few percentage points however are probably not significant. In Table 3~11, the percentage of plastic micro-litter to the other man-made material is almost exactly the same as with the larger items counted during GARBGobs. Table 3.11: Percentage By Weight of Plastic Among the Micro-Litter All Obs Pre-MARPOL Post-MARPOL n=118 n=49 n=69 Total kg % Total kg % Total kg % Plastic Items 86.12 84.7 38.58 87.6 47.54 83.8 Other Items 13.18 15.3 4.79 12.4 7.69 16.2 Natural items 3987.81 662.09 3289.85 3.5 Litter (Containers) By Quantity, Size, Material, and Country of Origin A 250-m stretch of San Jose Island was chosen just north of the north jetty of the Aransas Pass Channel as a site to collect containers on the beach. Other litter items were ignored. The study was conducted monthly from June 1991 through August 1992. Access to the beach was by boat. All ~ntainers (plastic bottles, jugs and pails, beverage cans, glass bottles and cardboard cartons) found on the beach from shoreline to dune line were collected, bagged and brought back by boat to the laboratory. There they were examined and classified for material, volume, weight, color and country of origin. The material classification is as follows: plastic, beverage (aluminum), glass, other can ("tin" food cans, etc.) and cardboard. 3.5.1 Number of Containers by Type As expected, the first month's collection netted the largest total of containers (648). San Jose Island is not cleaned and litter collects there until some event (storm, high tide, wind, [litter study]) removes or redistributes them. The histograms in Figure 3.29 show the relative proportions of each container type for each month. In general plastic dominates but beverage cans form a signifieant proportion of the containers. That proportion is less during the winter indicating that the source is most likely from recreational boats or visitors to this beach. Visitors must come via the "Jetty Boat" from Port Aransas and generally do not carry much equipment with them. Table 3.12 lists the numbers collected and the percentages of each material type for each collection. Figures 3.28 through 3.33 show the monthly totals for each container type by material. Plastic container numbers (Figure 3.29) dropped dramatically after the initial collection in June 1991 but from September 1991 through January 1992, monthly accumulations increasedJo nearly SAN JOSE CONTAINER STUDY ALL CONTAINERS COLLECTED 100-.-~~~~~~~~~~~~~~~~~~~~~~~~--, en soo ~ w 500 1-­ LL 400 0 0::: 300 0\ .+::-. w en z 100 0 ~200 ::J ········-·-·-·-···············-·-·-·-············-·-·-····-········ ... ·-·-·-·-······..·······-·-·-·-············-·-·-·--···-·-·-·-···············-····-··················-·-····-··"········-·-·-·-············..····-·-·-···············-······· ···················! JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG JUNE 1991 -AUGUST 1992 I • PLASTIC • BEVERAGE • GLASS • OTHER CAN • CARDBOARD Figure 3.28. San Jose Container Study: Relative Proportions of Each Container Type for Each Month. ~ SAN JOSE CONTAINER STUDY PLASTIC CONTAINERS COLLECTED 400--r-~~~~~~~~~~~~~~~~~~~~~~~~---, en ~300 w 1­ - LL 0 200 0:: w en ~ :J 100 z 0 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG JUNE 1991 -AUGUST 1992 Figure 3.29. San Jose Container Study: Number of Items Collected -Plastic. SAN JOSE CONTAINER STUDY BEVERAGE CANS COLLECTED CJ) ~ w 1­ - LL 0 O'\ O'\ 0::: w (() ::2: ::> z JUNE 1991 -AUGUST 1992 0\ .....J SAN JOSE CONTAINER STUDY GLASS CONTAINERS COLLECTED so-.-~~~~~~~~~~~~~~~~~~~~~~~~----, Cf) 40 :;? w I-­ LL 30 0 ~ w 20 (() :;? :::::> z 10 0 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG JUNE 1991 -AUGUST 1992 Figure 3.31. San Jose Container Study: Number of Items Collected -Glass. SAN JOSE CONTAINER STUDY OTHER CANS COLLECTED Cf) ~ w 1-­ LL 0 0-.. 00 ~ w en ~ ::J z JUNE 1991 -AUGUST 1992 .~ SAN JOSE CONTAINER STUDY CARDBOARD CARTONS COLLECTED 16 14 Cf) ~ 12 w t: 10 LL 0 8 0\ I"° 0::: w 6 CD 2: 4 :::> z 2 0 . JUN · JUL AUG SEP OCT NOV DEC JAN FEB MAR . APR MAY JUN JUL AUG JUNE 1991 -AUGUST 1992 Figure 3. 33. San Jose Container Study: Number of Items Collected -Cardboard Cartons. the same level as found in June 1991. For the rest of 1992 until the study ended in August, accumulations remained low. Beverage cans (Figure 3.30) were numerous in the summer of 1991, but decreased steadily remaining low until the start of summer 1992. The last two months of the study, beverage cans increased again. 3.5.2 Sizes of Containers 3.5.2.1 Volumes Containers on San Jose Island beach were found in a bewildering variety of volumes. The exception is the beverage can, nearly all of which come in one size, the standard American 12 oz. can. Volumes used were those stated on the label, stamped on the container itself, or in some cases, estimated. English units were converted into liters. To quantify the most numerous type of container, plastic, we classified them in three classes: larger than 3 liters, between one and three liters and less than one liter. Figure 3. 34 is a bar diagram showing the three volume classes plotted by month. Bottles less than one liter dominate most months, but one-gallon milk jugs which account for most of the containers larger than 3 liters, are a significant volume of the total from September through December 1991 and March and April 1992. The total volume occupied by the plastic containers was 3.36m3 and by all other containers was 0.49m3• 3.5.2.2 Weights Most assessments oflitter on beaches, including the nation-wide volunteer beach cleanups, have compared the weight of material collected from one cleanup to the next (Figure 3.35). In this study we measured both the weight and volume of the containers. Table 3.13 compares the total weight and volume of containers collected by type. Table 3.13: San Jose Island Container Study: Comparison of Total Weight and Volume Description Weight(kg) Volume(liter) Plastic 239.39 3355.81 Beverage cans 49.21 306.68 Glass 68.13 96.29 Other cans 14.12 59.37 Cardboard 6.59 27.25 Total 4 377.75 3845.40 SAN JOSE ISLAND CONTAINER STUDY SIZE OF PLASTIC ITEMS 250~~~~~~~~~~~~~~~~~~~~~~~~~-, Cl) ~200 w I­ ~ 150 ··1f•···-······-·····················-···········-········-·······-·-·-··--·-····-····-·····---····-······-·····-·-···--·····························-··························· ............................. . . ........) ffi 100 ...j[.. -----.. ·······--· ··-·..··-·····-··-···-···--······"'····-··--······················· . .······ .····· · ··················· ················• N co .. ~ 50 :) z JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG JUNE 1991 -AUGUST 1992 I• LARGER THAN 3 LITERS • BETWEEN 1 AND 3 LITERS • SMALLER THAN 1 LITER I Figure 3.34. San Jose Container Study: Volume Cl~sses Plotted by Month. SAN JOSE ISLAND CONTAINER STUDY TOTAL WEIGHT OF COLLECTION 120-.-----~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ (/) E 100 ro '­ 0> 0 == 80 ~ '-"" J­I so .......) VJ C.9 - w <( l-20 0 l­ 0 JUNE 1991-AUGUST1992 Figure 3.35. San Jose Container Study: Total Weight by Month. 3.5.3 Container Origins (by Country) Products made and sold in the USA dominate in number the containers found on San Jose Island beach. Figures 3.36 through 3.40 show the breakdown by container type and "geographical" origin (USA, Mexico, foreign, unknown). Appendix H lists each container and its country of origin when identified. Over half of all the plastic containers (Figure 3.36) originate in the USA, but in some months, Mexican bottles equal or even exceed the US total. Except for June 1991, plastic bottles identified as foreign make up less than 20% of the total. The unknown (unidentified) category are probably of non-US origin. Beverage cans (Figure 3.37) are almost exclusively from the USA or imported and sold here. Far fewer glass, metal can and cardboard containers originated in Mexico so they were classified with the foreign material for the rest of the figures. The majority of glass containers (Figure 3.38) are of US origin but more than half of the other cans (food cans other than beverage, Figure 3.39) are foreign. Most of the cardboard containers are from the USA. (Figure 3.40). 3.5.4 The Turtle-Bite Problem Many of the plastic and cardboard containers collected on San Jose Island had holes or cuts in them resulting from sea turtle bites. The author has long noticed this phenomenon on litter observed on Mustang Island and the present project afforded a chance to determine the magnitude of the problem. Nearly 60% of stranded loggerhead turtles examined (Plotkin and Amos, 1989) had plastic pieces in their gut. Figure 3.41 shows the number of plastic containers with turtle bites. Figure 3.42 expresses the data as a percentage of the total number of bottles. The mean-Jor San Jose study was 12.5 bottles with bites or 8.7% of the total. It is believed that juvenile turtles during their pelagic stage feed on the windrows and patches of weed and litter and attempt to eat plastic either because it looks like a food item or has animals growing on it (Amos, in prep). 74 .. p -.) V\ SAN JOSE ISLAND CONTAINER STUDY ITEMS BY COUNTRY -PLASTIC 350 -.-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-. en 300 :? 1-w 250 - LL 200 0 c:::: 150 w en 100 :? :::> 50 -· z 0 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG JUNE 1991 -AUGUST 1992 I • USA • MEXICO • FOREIGN • UNKNOWN I Figure 3. 36. San Jose Container Study: Number of Items by Country -Plastic. SAN JOSE ISLAND CONTAINER STUDY ITEMS BY COUNTRY -BEVERAGE CANS 200 en ~ w 150 I-­LL 0 100 0::: -......) O'. I w a:l ::;;? 50 :::> z 0 I•USA • FORIEGN • UNKNOWN I Figure 3.37. San Jose Container Study: Number of Items by Country -Beverage Cans. ., ,. ~ SAN JOSE CONTAINER STUDY ITEMS BY COUNTRY -GLASS 50 - en ~40 w I­ - LL 30 0 '-.) I 0::: '-.) w 20 cc ~ :::> 10 z 0 JUN . JUL AUG SEP . OCT NOV DEC JAN FEB MAR APR MAY JUNE 1991 -AUGUST 1992 I • USA • FOREIGN • UNKNOWN I Figure 3.38. San Jose Container Study: Number of Items by Country -Glass. SAN JOSE ISLAND CONTAINER STUDY Cl) ~ w -I­ LL 0 Ck:: -...J 00 I w en ~ :::> z ITEMS ·sy COUNTRY -OTHER CANS 40 30 20 10 0 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG JUNE 199 1 -AUGUST 1992 •:t:rt:::: UNKNOWN I l.USA FOREIGN :::::::::::::::::::• •.. Figure 3.39. San Jose Container Study: Number of Items by Country -Other Cans. " • l . SAN JOSE ISLAND CONTAINER STUDY ITEMS BY COUNTRY -CARDBOARD CARTONS 16 Cf) 14 :? w 12 I­ -10 LL Oa 0:: ·...J '-0 Ws en ~4 ::) Z2 0 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG JUNE 1991 -AUGUST 1992 I.USA • FOREIGN I Figure 3.40. San Jose Container Study: Number of Items·by Country -Cardboard Cartons. SAN JOSE ISLAND CONTAINER STUDY PLASTIC ITEMS WITH TURTLE BITES 400~~~~~~~~~~~~~~~~~~~~~~~~~~ en ~ w 300 J._._ J!lll....... -·-·-·-···············-·-·-·-············-·-·-·-·-············-·-·-·-···············-·-;~~-·······1111·-·-·-·-············-·-·-·-···············-·-·-·-············-·-····-··················-·-·-······"··········-·-··· ····················· -·-······· · ··· ······ · · I­ LL 0 200 -l·-····--1118811········-························-·-·-·-············-·eJllll.·-···········i118111-··-···············-·-·-·-·······11811111·-·-·-·-············-·-·-·-··················-·-·-············-····-····-············-·-·-·····················-·-·-···············-····-···············-······ 00 et: 0 w CJ ~ 100 --·-·-·--········-·-···-········ ··-··-······ ·· ··-·-·-········ ·-···········--·-·-·······-·-·-·-·-·-1111111··-·-·-·-··················-·-·-············-·-····-·-····· ····· -·-·-·-···············-·-·-·-·········································· ···l ::l z 0 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG JUNE 1991 -AUGUST 1992 ' I•WITH BITES • TOTAL ITEMS I Figure 3.41. San Jose Container Study: Plastic Items with Turtle Bites. . • . ' 00 ........ ) • . ' . ­ SAN JOSE ISLAND CONTAINER STUDY PERCENTAGE OF ITEMS WITH TURTLE BITES 25~~~~~~~~~~~~~~~--"--~~~~~~~~~~ 20 -i·-·-·-·-············-·-·-·-···············,;;;;;;;;;;;,············-·-·-·-·-· ··········-·-·-·-···············-·-·-·-·······-···-·-·-·-·-···-··-···-·-·-·-···· ··········-····-·-· ........·-·-·-············· ····-·-·-·-·················-············· ·······-·-······· .... . w (9 c::( 15 -!····-·-·-············-····-·-·············· 1­ z w () 1 0 -+·-·-·-·-············-· 0::: w a_ 0 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG JUNE 1991 -AUGUST 1992 Figure 3.42. San Jose Container Study: Percentage of Items with Turtle Bites. 4. DISCUSSION Annex V of MARPOL which prohibits the discarding of plastics at sea went into effect on 31 December 1988. Materials dumped at sea, including plastics, often find their way to beaches. Texas beaches in particular receive a heavy load of man-made debris due to their geographic location, the circulation patterns in the Gulf of Mexico and the volume of merchant marine, fishing, and recreational activities and the offshore oil industry in the gulf. Plastic and other litter on beaches have an adverse effect on tourism, pose a health threat to beachgoers, and cause serious problems with marine wildlife which can become entangled in or ingest the litter. It has been widely hoped that enactment of Annex V would reduce the litter on beaches. Therefore, a survey of a beach known to receive large quantities of debris from off shore, if done before and after the enactment of MARPOL Annex V, should indicate the degree of compliance with the law. In the follwing discussion I will briefly review survey methods, compare three other current surveys with the MMS-Beach survey, and make some observations on how future surveys might be conducted. 4.1 Beach Debris Survey Methods Government agencies need to rely on beach debris surveys as one method of assessing the degree of compliance with or enforcement of MARPOL Annex V. A standard method of conducting beach debris surveys is needed if results from different locations done by different investigators are to be comparable. Dixon and Cooke, 1977 reported one of the first surveys to examine man-made items washed ashore on beaches. They began their surveys in 1973. Ribic et al. (1992), in their Marine Debris Survey Manual consider both shipboard and beach surveys. While both are applicable in the study of marine debris, for the present discussion, only the beach survey methods are considered. Amos (1993) compared four methods currently .in use, including his own survey techniques. I will summarise the results of those comparisons here with reference to the Gulf of Mexico and specifically, Texas. Some of the following has been paraphrased or excerpted from Amos (1993). 4.1.1 Objectives Ribic et al. (1992) state that "different survey designs are necessary to address two objectives", baseline and trend-assessment. I list five possible objectives for doing beach­debris surveys; 1 Trend assessment: Is the quantity of marine debris on beaches decreasing or increasing? 2 Identification of sources: Who is responsible for the debris on the beach? 3 Environmental conditions controlling marine debris on beaches: What controls the beaching of marine debris? 82 4 Assess the effect of marine debris on a beach: Does the debris present a threat to human visitors, a detriment to the economy of a community? 5 Effect of marine debris on wildlife: How detrimental is marine debris to animals whose habitat includes nearshore waters and beaches? Although I believe all these objectives should be considered in any comprehensive study, it is objectives one and two I will discuss here. 4 .1. 2 The Ideal Survey Conditions Let us assume that for trend assessment, the basic survey method is to remove all debris from a given beach transect for examination later. For perfect results, all material would be removed by the surveyors and only the surveyors, and all new material beached after one survey remained there until the next. Errors would be limited to counting accuracy and the ability to identify materials. Pilot surveys could then be done to determine the optimum surveying interval and distance to survey. As Ribic et al. (1992) point out, a suitable statistical scheme should be decided to aid in analyzing the data. It would not matter where the debris originated if the objective of the survey was solely to establish a baseline and subsequently to investigate trends. ·For source association, however, the ideal would be that indicator items unique to each offshore source could be clearly identified as such. The counting method used as part of the present MMS Beach survey also-has the same ideals, including removal following each survey. The removal does not have to be done by the surveyors. Counting and identification skills play a larger role in the accuracy of the results. Unfortunately, such ideal conditions do not oecur. 4.1.3 The Real World In the real world, several peculiarities of the distribution of beached debris make accurate surveys most difficult to obtain. I list some below. 1 Longitudinal and latitudinal debris distribution: debris is distributed non-linearly both along the shoreline and across the beach width at any instant in time. Temporally, it is beached at frequencies ranging from tidal to daily, weekly, seasonally, and inter­annually. 2 Debris dispersal and concentration: Once on the beach, debris is dispersed by winds and tides, or concentrated by accumulation at dune lines. The same items may be repeatedly dispersed and re-beached. 3 Debris burial: Burial of debris takes place in the foreshore, swash zone, backbeach, and dunes. Burial and exposure may be frequent occurrences. 4 Debris removal: Many municipalities, resort beaches and counties have beach­cleaning programs. These often sporadic efforts greatly effect results of beach debris surveys on such beaches. Debris sources: All beach debris does not come from offshore. Yet many items are used by beach users, offshore industries, and land-based sources. Separating these is one of the most difficult aspects of beach debris studies. 4.1.4 Choosing a Beach From the above it would seem that some of the variables could be eliminated by using a remote, uncleaned beach to survey. The following criteria must be considered in selecting a remote survey beach: !--Availability of a 4-Wheel Drive or all-terrain vehicle. 2--Proximity of a building for a counting/staging area. 3--Availability of a boat or other conveyance to get to the beach. 4--Proximity of headquarters of surveying group. 5--Availability ?fa place to dispose of the collected material. Using Texas as an example, I find just eleven suitable beaches covering just 50 of the 350 miles of Gulf coastline. Not all of these are ideal. The beaches are described in detail in Amos (1993). 4.2 Comparison of Four. Beach Debris Surveys To examine the options used in completed or on-going surveys for beach debris, I summarize the suitability of four recent efforts, including the MMS Beach surveys (Table 4.1). 4.2.1 Island Beach State Park This survey is being done monthly by volunteers from the Alliance for a Living Ocean (ALO). The Center for Marine Conservation (CMC) organized this survey and analyzes the data under a grant from EPA. The survey is based on a statistical design (Ribic, 1990) and is conducted on the Island Beach State Park facing the Atlantic Ocean. The section of the beach used for the survey has greatly restricted use under Park regulations and is not cleaned. At 28-day intervals, a 500 meter transect is surveyed by collecting all debris found there. Two adjacent 500-m transects were examined for littoral drifted items but this scheme was later abandoned. Starting in May 1991, 26 surveys have now been completed (E. Gotshall, pers. comm.), of which 23 are analyzed. The mean weight in kg.km-1 of all items per survey {n=23) is 16.6 (7.0); maximum, 54 (21.8); minimum, 4.6 (1.4); Standard Deviation, 8.29 (3.49). Numbers in parenthesis are quantities of all plastics. Compare this with the San Jose Island values {n= 15) of mean, 100.6 (63.8); maximum, 420.8 (252.4); minimum, 21.3 (11.4); SD, 99.3 (66.1). 84 ~ Table 4.1: Beach Debris Survey Examples (modified from Amos, 1993) location objectives dist (km) freq 1 Island Beach, NJ trends, littoral drift 1.50 Monthly 2 Padre Island National Seashore, TX trends, target sources littoral drift 0.05 (4 sites) Daily 3 Mustang Island, TX San Jose Island, TX (Coastal Cleanup) clean beaches, trends, education up to 3.75 1.00 2/Year 4 Mustang Island, TX Mustang Island, TX Mustang Island, TX San Jose Island, TX trends, sources micro debris sources, trends sources 11.80 0.01 (3 sites) 11.80 0.25 Weekly Weekly Alternate days Monthly Note the large differences in the transect distances used in these surveys. The mean weight of plastic on the Texas beach is about an order of magnitude greater than that on the New Jersey beach. Because of this, and because the method requires volunteer workers, I conclude that this survey method would not be suitable for use in Texas. The work would be particularly arduous if the littoral drift study was included in a Texas survey, as it was when I observed the New Jersey effort in 1991. 4.2.2 Padre Island National Seashore The National Park system has had a Marine Debris Monitoring Program since 1988 (Cole et al., 1990). Surveys are conducted at eight National Parks and Seashores on all U.S. coasts. Surveys are conducted quarterly. The Padre Island National Seashore in Texas is recognized in this program to be a special case due to the volume of materials beached there. While PAIS still does the quarterly surveys they have embarked on an ambitious daily survey that is now nearing its one-year completion date. It is this survey I will summarize here. Four 50-m transects of beach are surveyed daily, two within the Closed Beach, and two outside in an area where automobiles are permitted but where the beach is not cleaned. Doing the survey daily was a revelation to the PINS group (J. Miller, pers. comm.). They soon discovered that the quantity of the 'resource' was highly variable within this sampling period. The team made careful efforts to quantify littoral drift and burial of man-made debris, especially -near the dunes. As a result of this, they now feel that the returns from looking at the debris which is in the main dunes produces limited results of questionable value to their overall goals. More in keeping with their objectives was the discovery that debris positively identifiable with the shrimping industry not surprisingly came ashore when the Gulf shrimpboats were working nearshore (i.e. their boats were visible from the beach). At first volunteers were used but now they use only PAIS personnel to carry out the program. Such intensive surveys require a large operating budget. 4.2.3 Mustang/San Jose Islands (CMC) The most extensive of all the beach debris surveys and cleanups is the International Coastal Cleanup organized by CMC. Now in its sixth year, the data base is huge, with thousands of entries from data cards filled out by volunteers entering up to 81 categories of debris items (CMC, 1992). CMC does not claim that their survey design is based on rigorus statistical foundation (O'Hara, 1990), but the data base is large enough that it needs to be scrutinized to determine if reliable trends can be realized. Some independent analysis has been done on specific beaches cleaned by volunteers (Lindstedt, 1991). I have done several comparisons of debris on the beach immediately before and after the cleanups on Mustang Island and one detailed analysis of items recorded versus what was actually collected on San Jose Island (Amos, 1993). Can the CMC data with its thousands of volunteers and large coverage of the Nation's beaches be used as a measure of trends and or identification of debris sources? Did the volunteers get everything off the beach and are the data cards accurate when compared to what was actually collected? Volunteers did a good job in removing large items of litter from the beach. They were less successful in removing fragments of styrofoam and plastic pieces. Sections of the beach were missed entirely because it is not possible to assign volunteer groups to the entire beach, especially the more remote ones. In recording items, the volunteers were again quite accurate with large, easily identifiable objects. However, some errors were surprisingly large for familiar · items (esp. beverage cans). They fared less well on both counting and identifying smaller, more nebulous items. In the result of the one experiment, the overall error was 50% undercounting. There were errors in recording how many collection bags were filled. Of the 127 bags we collected for analysis, 111 were listed on the data sheets. Widely-published headlines, e.g. "1400 Tons of Trash Collected from Nation's Beaches" are based on th~ bag count and a mean recorded on the cards and an estimated mean weight per bag. Our experiment gave a mean weight of 13.5 lb per bag (n=127, SD=17.2). Eleven percent of this weight was due to sand, not counting that difficult to remove from bottles and cans. An additional weight, equivalent to 3.1 lb per bag, was accounted for by large, unbagged items. Using numbers from CMC, (1992) and our mean bag weight, we calculate that there were 10.9 bags per data card turned in to CMC. This is twice the number obtained in our experiment (5.8 bags/card). The above is the result of only one experiment and is not meant to detract from the immense utility and public service that the International Cleanup provides. Some of the trends in the CMC data mirror those found in the MMS beach study presented here. If the CMC Cleanups are to be used for trend assessment and source identification then more control experiments like the one done by Amos (1993) should be done at spot locations around the country by trained observers. The CMC data base may be compared to another, once maligned data set collected by volunteers, the Audubon Christmas Bird Count (Drennan, 1981). Trends in bird populations 86 are being analyzed using the CBC data. 4.2.4 Mustang/San Jose Islands (MMS) The four kinds of surveys have been described in detail in the present report. An important finding from the counts is that the quantity of debris beached varies by several ' standard deviations from the mean, as a function of both time and location along the beach transect. Advantages of debris counting over collecting are; 1) a much longer transect can be used; 2) debris data can be entered directly into a computer on-site; 3) longitudinal debris distribution can be mapped in real time; 4) A single observer can conduct the surveys; 5) a count could include only easily recognizable and countable target items thus reducing the time and effort required. Disadvantages using this method are; 1) items may be re-counted in subsequent surveys (not a disadvantage if the objective is to quantify the debris standing stock); 2) a certain skill and consistency in counting technique is required; 3) items may be missed if the swath counted is wide or if they are obscured by natural debris. A long-term project like the MMS beach survey may be compromised ·if the beach usage and cleaning efforts change during the course of the survey. The difference between the San Jose Island container study and other debris collection surveys is that only certain items were collected. While this made the field work easier, the work back at the laboratory was more detailed. Every item was examined, classified, weighed, · and described in detail as the focus of the study was to identify sources. If materials discarded at sea by vessels under MARPOL's regulations were the only litter found on the beach, then it might be said that any reduction noted was due to compliance with Annex V. Unfortunately Mustang and San Jose Island beaches receive additional litter from beachgoers and from the rivers, bays and estuaries (although some of these waterways also come under the MARPOL regulations). Mustang Island beaches are cleaned by local authorities making assessment of debris and litter input difficult. Part of the study beach has been cleaned more vigorously recently but the effort is still seasonal and unpredictable. Litter washed ashore is also subject to redistribution by storms, winds, high tides and sand burial. Despite these variables, the study has shown some significant changes in the quantity of litter on the study beach since MARPOL went in to effect. Several of the most commonly found types of litter have been declining since 1989. The lesson from the above surveys is that trying to assess 11everything11 which is stranded on a beach requires immense effort, fortitude and time, especially with limited personnel to do the assessing. 4.3 Future Beach Debris Surveys Drawing on the lessons learned from the present study and other beach debris surveys, I list here some criteria for future surveys to study beach debris. For trend assessment and source identification, surveys must be done frequently, on a remote beach, cover a length of beach sufficient to avoid extrapolation errors, use trained personnel, and perhaps target only a .. few indicator items. The study period should cover at least one year and preferrably longer. Duration: Multi-year, or one-year for source identification. Frequency: Weekly or less (monthly for source identification on remote beach). Length: At least 1-kilometer. , Width: Limit to area between shoreline and high tide line. #Surveys: In Texas, three or four to cover the-coastline and the current regimes. Location: Remote, uncleaned beach with access by boat and availability of vehicle on-site. Remote, uncleaned beach with access by 4-wheel drive vehicle. Selected beach with easy access, could be cleaned but need cooperation of beach personnel. Proximity of research or marine regulatory agency facility. Basic methods: Use trained personnel. Collect debris and clear site after each survey. Select target items to avoid logging every piece of plastic. Counts of target items . okay for longer transects. Use controls and estimate errors. Collect ancilliary environmental data. Special surveys: Surveys of longer beach transects using existing beach-cleaning personnel (they should be trained) to collect and researchers to examine. Surveys which target specific items or sources. Ancilliary data: Reliable data on quantities and types of supplies that the various maritime industries use at sea. Canvass industry at)d professional organizations. Port, shipping and fishing industry statistics. Weather and oceanographic data. 5. CONCLUSIONS The number of people visiting the beach has increased as _has the attendant activity and potential for litter input. Beverage cans, the most common of beachgoer litter on the beach, have remained steady; but plastic six-pack rings, cups and lids and cloth have all decreased. Paper products, balloons and toys have increased. Two items of natural debris (Sargassum weed and driftwood), important because of their association with floating litter at sea, have increased. Tarballs have decreased and this trend has been of sufficient magnitude to have been noticed by the public at large. Of the items associated with the fishing industry (mainly shrimping in the study area), several have declined including milk jugs and egg cartons, typical shrimp-boat galley waste. In contrast Mexican bleach bottles and produce sacks have increased. Items associated with the offshore oil industry have decreased: in the case of the large plastic sheeting and write-protect rings, dramatically so. The 5-gallon plastic pail with labels showing various chemicals used by the offshore industry has also declined significantly. Items from the maritime 88 commerce business are more difficult to identify but typically are galley-waste peculiar to that industry with many bearing foreign labels. The one-liter cardboard milk carton, sold almost exclusively by ship's chandlers, has declined. Galley waste, in general, has declined with the exception of plastic bottles. The source of such bottles is not exclusively galley waste. The origins of the most numerous forms of litter on the beach, styrofoam pieces, plastic bags, and miscellaneous plastic pieces are not known and are probably from multiple sources. Styrofoam and plastic bags have noticeably declined while the miscellaneous material has increased. When assessed by weight rather than count, both styrofoam and (miscellaneous) plastic show declines. The overall conclusion from this study is that after MARPOL the quantity of litter from marine sources on the study beach has been reduced. It cannot be determined statistically from the data that this is due to compliance with MARPOL Annex V regulations. The author believes from the circumstantial evidence that MARPOL is beginning to have a beneficial effect on the beaches of Texas. 6. REFERENCES Amos, A.F. 1989. The Annual Cycle of Temperature, Salinity and Tides at the South Texas Gulf Shoreline: A Multi-year Study. American Geophysical Union, Chapman Conference on Physics of the Gulf of Mexico, June 4-7, St. Petersburg, Florida. Amos, A.F. 1993. Technical Assistance for the development of beach debris data collection methods. Final report to U.S. Environmental Protection Agency under Cooperative Agreement No. X-006623-01-0. U.T. Tech. Rep. TR/93-002. Amos, A.F. (in prep) Turtle Bites: Evidence for -Sea Turtles Ingesting Plastic, Paper, Cardboard, and Metal Foil. Marine Turtle Newsletter. Cipriani, G.R., R.S. Wheeler, and R.K. Sizemore. 1980. Characterization of Brown Spot Disease of Gulf Coast Shrimp. J. Invert. Pathol. 36:255-263. CMC (Center for Marine Conservations). 1992. 1991 International Coastal Cleanup Results. Center for Marine Conservation, Washington, D.C. 470 pp. Cole, C.A., W.P. Gregg, D.V. Rickhards, and D.A. Manski. 1992. Annual Report of National Park Marine Debris Monitoring Program. NOAA Technical Report NPS/NRWV/NRTR-92/10. 56 pp. Dixon, T.R., and A.J. Cooke. 1977. Discarded Containers on a Kent Beach. Marine Pollution Bulletin. 8: 105-l 09. Drennan, S.R. 1981. The Christmas Bird Count: an overlooked and underused sample. Stud. Avian Biol. 6: 24-29. Lindstedt, D. 1991. Marine Debris at Fourchon Beach: A Pilot Project. Final Report on EPA Grant X006590-01, Louisiana Geological Survey, School of Geoscience, Louisiana State University. O'Hara, K.J., 1990. National Marine Debris Data Base: Findings on Beach Debris Reported by Citizens. In Shomura, R. S. and M. L. Godfrey (eds.). Proceedings of the Second International Conference on Marine Debris, 2-7 April 1989, Honolulu, Hawaii. U.S . • Dept. of Commerce, NOAA Technical Memorandum NMFS-TM-NMFS-SWFSC-154. Pp. 379-391. .. Plotkin, P.K. and A.F. Amos. 1989. Effects of Anthropogenic Debris on Sea Turtles. In: Proceedings, Second International Conference on Marine Debris. NOAA Technical Memorandum NOAA-TM-NMFS-SWFSC-154(1):736-743. Ribic, C.A., and S. W. Johnson. 1990. Guidelines for the design of beach debris surveys. • In Shomura, R.S. and M.L. Godfrey (eds.). Proceedings of the Second International Conference on Marine Debris; 2-7 April 1989, Honolulu, HI, U.S. Dept. of Commerce, NOAA Technical Memorandum NMFS-TM-NMFS-SWFSC-154. p. 392­ 402. Ribic, C.A., T.R. Dixon, and I. Vining. 1992. Marine Debris Survey Manual. U.S. Department of Commerce, NOAA Technical Report NMFS 108. 92 p. ' ; 90 Form Approved REPORT DOCUMENTATION PAGE OMB No. 0704-0788 Public reporting burden for this collection of 1nformat1on •S '.:'st1mated to average 1 hour per respor.se. including the time for reviewing instructions. searching existing data sources. gatheflng and matntil1n1ng the data needed. and completing and reviewing the collection of 1nform,n 1on. Send comment> regarding this burden estimate or any o ther aspect of this collection of informat ion. including suggestions for reducing this Durden. to Washington HeadquMters Services. Directorate for Information Operations and Reports. 1215 Jefferson Davis 111ghw ay. Suite 1204. Arlington. VA 2.2202-4302. and to the Office of Management and Budget. Paperwork Reduction Project (0704-0188). Washington. DC 20503. 1. AGENCY USE ONLY (Leave blank) 12. REPORT DA TE 3. REPORT TYPE AND DATES COVERED July 1993 FINAL 1 4. TITLE AND SUBTITLE Solid Waste Pollution on Texas Beaches: A Post-MARPOL Annex V Study; Volume I: Narrative ' 6. AUTHOR{S) Anthony F. Amos 7. PERFORMING ORGANIZATION NAME(S) AND AODRESS(ES) The University of Texas at Austin Marine Science Institute P. O. Box 1267 Port Aransas, Texas 78373-1267 9. SPONSORING I MONITORING AGENCY NAME(S) ANO ADDRESS( ES) U.S. Department of the Interior Minerals Management Service Gulf of Mexico OCS Region 11. SUPPLEMENTARY NOTES This is Volume I of a two-volume r ·eport. 12a. DISTRIBUTION I AVAILABILITY STATEMENT 13. ABSTRACT (Maximum 200 words) 5. FUNDING NUMBERS c 14-35-0001-30546 8. PERFORMING ORGANIZATION REPORT NUMBER TR/93-001 10. SPONSORING I MONITORING AGENCY REPORT NUMBER OCS Study MMS 93-0013 12b. DISTRIBUTION CODE The International Convention for the Prevention of Pollution from Ships (MARPOL) adopted Annex V, prohibiting the discharge of plastics into the ocean, on December 31, 1988. To see if compliance with MARPOL Annex V reduced the quantity of marine debris on a Gulf of Mexico _beach, surveys were conducted from January 1991 to June 1992. These data were then compared with the results of surveys done in 1987 and 1988. Three types of surveys were done along a 12-Jan stretch of a Mustang Island, Texas, beach and another on the adjacent San Jose Island. Two main methods were employed: counting large items in situ, and collecting small and certain targeted items for later classification and analysis. Counts were done at 2-day, weekly, and monthly periods, and collec­tions made weekly and monthly. Results show reductions in the quantity of marine debris in the post-MARPOL period. Several items identifiable with the offshore oil, commercial fishing, and merchant marine industries were reduced in quantity. Circumstantially, this might imply the early success of Annex v, • but the direct link was not established. A brief review of beach-debris methods other than the author's is included in the discussion. 14. SUBJECT TERMS MARPOL Annex V, Marine Debris, Gulf of Mexico, Pollution, Beaches, Plastics, Maritime Industries 15. Nt1MBER OF PAGES xii + 90 16. PRICE CODE 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT OF REPORT OF THIS PAGE OF ABSTRACT UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED UL NSN 7540-01 ·280-5500 Standard ;:orm 2913 ( ~ev 2-89 ) J ... •