• • AN ASSESSMENT OF THE SPORTFISHERY ON ARTIFICIAL "LIBERTY SHIP" REEFS • OFF PORT ARANSAS, TEXAS SEP 1977 • A report to the Texas Coastal and Marine Council in fulfillment of Contract No. IAC(76-77}-2149 • Submitted by Russell D. Vetter Oswald A. Reels The University of Texas Marine Science Institute • Port Aransas Marine Laboratory Port Aransas., Texas 78373 • T~LIBRARY • OF I'HE UNIVERSITY OF TEXAS A..,., AUSTIN • Submitted September 1977 • • I. INTRODUCTION • The concept of using surplus World War II Liberty Ships for the construction of artificial reefs to increase the availability of sportfish off the Texas coast was originally suggested in 1974. It became a reality, under the guidance of • the Texas Coastal and Marine Council, when three ships were sunk off Port Aransas in the winter of 1976. Since that time, the• ~hips have rapidly become encrusted with algae, anemones, sea urchins, gorgonian coral and other attached marine life. These in turn have provided refuge and food source for a host of small• invertebrates and fishes. In June of 1977, one and a half years after ·sinking the first ship, the Texas Coastal and Marine Council commissioned• this study to evaluate the impact of the Liberty Ship reefs on sportfishing in the Port Aransas area. For a project such as the Liberty Ship reefs to be successful, there are two criteria: • the ships must increase the supply of desirable sportfish and fishermen must be willing to utilize the new resource. The present study is an attempt to evaluate both aspects of the • project. A user survey was conducted to determine the amount and type of recreational usage the Liberty Ships receive. • II. SURVEY OF RECREATIONAL USAGE OF THE. LIBERTY SHIP REEFS • Although many studies of this type have recorded usage on a per individual basis (Buchanan, 1973) this was not suitable for the present study due to the high turnover rates of visiting recreational fishermen. Instead, data were recorded on a per • • 2 boat basis and emphasis was placed on boats that occupied a • permanent boat slip throuqhout the study period. This same • technique is used by the National Marine Fisheries, Oceanic Gamefish Investigations and has proved highly successful. To meaningfully assess recreational usage of the Liberty Ships, fishing and recreational diving interests were separated into five user groups. Group 1 comprises party or "head" boats • that offer regularly scheduled fishing ·trips with payment on a per individual basis. Group 2 are private charter boats generally carrying 2-6 anglers on a group contract basis. • Group 3 are private recreational boats 28 feet or greater in length• Group 4 encompasses private recreational boats under 28 feet long. Group 5 consists of all recreational divers. • There are six party or "head" boats that routinely operate out of Port Aransas during the summer months {Table 1). Fishing trips generally last four or eight hours with bait and tackle • supplied by the operator. Two party boats operate out of the Deep Sea Headquarters: the Marlin Queen I, 91 fet. and the Marliln Queen II, 60 ft. Fisherman's Wharf operates two catamarans; the • Wharf Cat, 80 ft. and the Scat Cat, 75 ft. Rick Corn's Sportmans Center operates the Pelican, 45 ft. and Dolphin Docks runs the Dolphin, 65 feet. These boats operate every ·day during June, • July and August, weather and mechanical considerations permitting• This represents a potential total fishing effort of 552 boat-days• • • 3 ,,. ,,,_, ,, I # ,,,"' ,,',' 2a0oo I ,,,,, , , #,, ,',', , .. ,,I ,.. , ,,, I ,, .---· I ,., I ,, , ,,.--_,,, ,, '\ , ,,,. , ,.,,,,,,, -?o> / .,,, ---, , ~-<" ~ I .' ,I ~ ,I \P ,,,•I ,,,, Loran Liberty 3H3 •205~ ,,. ,,I 3H2 394l -Ships .,. ,,, , , ,, :', ,I ,I ,, , .,I ,. .. ' I ,, ., I I ,I I I . , I . ,I ,,. 10 fathom 29 fathom 30 fathom I ,. ,I I I , ,I I ,I ,' .. . I ,, I . 97°00 1 . I I. ,· . :;_ ... •• ~ -·-:~:..:.:. "7 • --==============::::=::::::::::::::::::::=-----·-- ----------·~· .:~. -~·"'.::..~_:,.;;:·;;~.:~~~:~i~ . ... • • • • • • • • • · -­ • • • • • • • • • • / 0/ / ~~ Loran readings 3H3 2059 3H2 3941 !? 0 0 ­ !-. ·: -• ·-· ":' -·:. -::.:; ,.---..-···---------·-------·... -----------· ---·-·---·: ··.·'.:·.~~=- -----:. ::~.tr:~~~~.-.:·-':...t.~ --~ .:.: • 5 1 • Utilization by Party Boats • Table I Party Boats Participating in Survey • • BOAT NAME RESPONDENT UTILIZATION~ Wharf Cat Edward Shepard 0 Scat Cat Edward Shepard 6 Dolphin Warren Hamm 0 • Marlin Queen I Willis Langford 0 Marlin Queen II Willis Langford 4 Pelican Kennith Reiter 2 Shark Hunter Paul Dirk 0 1utilization is expressed as total boat-days fished during the • • three month study period This interest group directs its effort almost exclusively towards migratory, schooling, pelagic species. Early in the • season the primary species landed is the jackfish {Caranyx hippos·). Later in the sununer as jackfish landings decline, king mackerel {Scomberomorus cavalla) are the most important • species. The method of fishing from these boats is almost ex­clusively drift fishing, with anglers using dead bait fished from the surface down to a depth of 30 feet• • Utilization of the Liberty Ship reefs by regularly scheduled party boats during the months of June, July and August must be considered minimal. The portion of the total 552 boat-day fishing effort that was devoted to the Liberty Ship Reefs was only 12-boat days, including 4 by the Marlin • • 6 • Queen II, 2 by the Pelican and 6 by the Scat Cat. Two reasons for the low utilization of the reefs by this • interest group were time and fuel costs. The three boats that did not utilize the ships at all usually run four-hour fishing trips. These boats average one hour to one and one half hours • to reach the Liberty Ships and slightly less to return. The one and a half to two hours remaining for fishing is not suf­ficient to produce a satisfactory catch• • Aside from the time factor, the high cost of fuel is an important conside~ation. Most party-boat captains are able to find sufficient stocks of kingfish and jackfish around gas wells, drilling platforms, anchored shrimp boats and other features located within 10 miles off shore. The added cost of traveling 16 miles to the Liberty Ships has not been justified • by the size of the catches off the reefs. The total number of anglers fishing from party boats on the Liberty Ship reefs was 354 and the total fees paid were $9,760.00 for the three month study period. Although utilization during the summer months was low, all • people concerned with party-boat operations enthusiastically support the Liberty Ship reefs and indicated that they intended to utilize the reefs at other times of the year. When kingfish, • jackfish, ling and Spanish mackerel migrate away from this area with the onset of cool weather, party-boat operators must rely on other fish stocks. Traditionally, this has been bay fishing. • However, these species are declining in abundance. Red snapper and Warsaw grouper fishing trips to the Liberty Ships are offering • • 7· new fishing opportunities and new sources of revenue during the • off season• Although this user group is not as visible as the party boat business, charter boats constitute a large segment of the commer­ • cial sportfishing industry in Port Aransas (Table II}. Charter boat operators rely on word-of-mouth advertising and bookings arranged through party boat docks to obtain customers. They • generally average four anglers per trip, with ·trips lasting ei.ght hours. The method of fishing is either trolling or driftfishing at or near the· surface. Charter boat operators also rely primarily• on migratory schooling pelagic species such as kingfish, ling, jackfish and Spanish mackerel. • 2 • Utilization by Private Charter Boats Table II Private Charter Boats Pa~ticipating in Survey • BOAT NAME • RESPONDENT UTILIZATION! Bess & Fess John E. Mathews 3 Lady Bea Byrd Mintner 4 Poco II Charles Holmes 0 Hustler Jay Lancaster 1 Hustler II Rick Corn • 12 4 Hustler III Nick Fryar Lil Hustler Cricker Mathews • 0 Diablo Tom Lambertson 3 Peggy Sue Robert Butler 1 Schatzie Bob Palmer 6 • • 8 • BOAT NAME RESPONDENT· UTILIZATION! B-G Bruce Ponton 0 Colonel Rice II Randy TUrner 0 Mo-Jo Bob Kelly 0 • Sugarfoot II Ed Hall 0 Patti II Ken Grimes 10 Foolish Pleasure Gary Eincoff 2 • Sand Dollar Mac Carpenter 1 La Isla 100 Proof I• Wheeler Dealer NR Carla Ann o. H. Salyers 0 lutilization is expressed as total boat-days fished during the • three-month study period 2NR inqicates that the respondent did not return log book The cost of a private charter fishing trip is dependent on • the size and type of boat and the type of fishing desired. Char­ters generally begin at $150.00 for a party of four and can range over $400.00. The primary consideration of charter operators is • to provide an enjoyable fishing experience with a minimum ex­penditure of fuel and running time. This is the determining fac- I tor for utilization of the Liberty Ships by this group • • During the three-month study period, charter operators were surveyed to determine the amount of usage of the reefs. Almost all charters during this period fished for kingfish. Most • operators surveyed indicated that the reefs were too far and too unproductive of this species to justify the expense, the average • • 9 catch being four to five kingfish per trip. Of the group inter­ • viewed 11 boats fished the reefs at least once. Use averaged 2.5 • days per boat with a total of 49 days recorded for this group. The total expenditure by anglers fishing the Liberty Ship reef from this kind of boat was $12,356 • • Many charter businesses operate only during the peak sununer months. However, those that do charter throughout the year indi­cated that they intended to run red snapper and Warsaw grouper trips to the Liberty Ships during the fall ~nd winter. Although the reefs are not highly productive of kingfish, most operators • realize .that the reefs were not intended to significantly stimu­late pelagic fisheries. One charter operator who regularly fishes the reefs has been able to generate interest in barracuda fishing on the reefs as an alternative to kingfishing. In general, most charter operators are favorably impressed with the reefs and believe thay they have stimulated productivity. • This user group is composed of privately-owned boats generally operated by a professional captain, and possibly a mate, that de­vote most of their fishing effort towards off-shore species. The • 28 ft. or larger boat-length used to define this group, although arbitrary, does encompass most boats capable of safely operating at distances greater than thirty miles offshore. A list of boats • and participants in this part of the survey can be found in Table 3. · The primary species of fish that are sought by this group of anglers are the billfishes, blue marlin, (Makaira nigricans), white • marlin (Tetrapturus albidus), and sailfish (Istiophorus platypterus) • · • • 10 Other pelagic species conunonly landed include: dolphin (Coryphaena• hippuris), · wahoo (Acanthocybium -solanderi), blackfish tuna (Thunnus atlanticus), yellowfin tuna (Thunnus albacares) and Bonito (Euthynnus alletteratus). The method of fishing for these species• is almost exclusively trolling of natural or artificial baits at the surface. • 3. Utilization by Private Offshore .Boats • Table III Offshore Boats 28' and Larger Participating in Survey BOAT NAME RESPONDENT UTILIZATION! Hokus Polus Chris Page 0• A Boat Named Sue Curly Johnson 0 Carey On Jeff Carey 0 Mi-Mi Carlos Moore 0• Black Topper Jim Graves 0 Pixie Bruce Furlough 0 Breaker I Bob Hollinger 0• Coeco Bill Hart 5 Olympia III Bubba Curry 0 Wolverine Burton Curry 0 • Bessie W Tom Martin 1 Tempest Roy Smith 0 Rebel Tom Masterpole 3• Samaki Smokey Gaines 0 Webb Tide Jerry Webb a • • 11 BOAT NAME RESPONDENT UTILrZATIONl: • Hot Tamale Lefty Strong 0 Cora Belle Tom Keeler 0 La Tonina Fred Rhodes 0• Stella Mae II Doyle Merrick 0 Sundancer Corky Furlow 0 Mo Misery Scott Frost 3• Deep Sea c. D. Roger Goodwin 0 • Born Free Earl Rasberry NR2 Lorelei Louis Sczaborczk NR Pauper's Pride NR Kaydiddle NR Fractured Jaw Roger Byrne • NR Aquarian Glenn Mathison 0 Escort II Ro Chandler NR Jayhawker Ron Arbogast NR• Fat Daddy NR • !utilization is expressed as total boat-days fished during the three-month study period 2NR indicates that the respondent did not return log book The primary factors governing Liberty Ship usage by this group • are not the distance or economics of traveling to the reefs. Most • boats routinely fish at distances greater than the reefs. The main factor limiting usage of the Liberty Ships by this group is their single-minded devorion to billfishing. Many of these boats fish the Liberty Ships for Warsaw during the cooler months. However, during the sununer season they fish almost exclusively for billfish• • • 12 Four boats did utilize the Liberty Ships during the study either • for variety or when weather did not permit offshore fishing. They logged 12 boat-days. This user group was the most difficult to accurately survey e for several reasons. Most boat owners in this group do not perma­ nently moor their boats but prefer to keep them on trailers and launch them at various launching ramps when needed. The owners were • generally not ·present throughout the study period, but tended to actively fish for one or two weeks, then leave the area. People tended to return from fishing and retrieve their boats at the same • times I monitored the fish cleaning areas and were seldom present at other times during the week. For these reasons owners of boats in this group were and asked given log books to record the numbers • and types of fish they caught and the hours they spent fishing the reefs. These log books were to be mailed in at the end of August. People participating in this aspect of the survey are listed in• Table IV. 4• Utilization by Recreational Boats Under 28 Feet • Table IV Inshore Boats Under 28' Participating in Survey • • • BOAT NAME Granny J Sunchaser My Fair Lady Jeannie Bell II Stella K 1 RESPONDENT UT·ILTZATION Wilburn Rocket 4 Wayne Kirby 0 Charles Craig 0 Russ Williams 0 Joe Klonek 2 13 BOAT NAME RESPONDENT UTILIZATIONl Mako 19' Bill Cleveland 0 Boca Chica Paul Kennedy Shana Lee W. c. Gustofson Flo's Boat Bob Jones NR Blodgett Ed Collett NR Peanuts F. A. Price NR Misty Dawn James Rice NR Blue Fin NR Myra Jean NR Miss Billi NR Blue Eyes NR Galadriel Mark Poff 0 24' Ken Winters 0 20' James Cameron 0 lutilization is expressed as total boat-days fished during the three-month study period 2NR indicates that the respondent did not return log book The limiting factor determining usage of the Liberty Ships by this group is the wind and sea conditions. The Liberty Ships are located off Port Aransas at a compass heading 145°. It is necessary for boats to run directly into the prevailing southeast sununer .winds to reach the ships. Most recreational boat operators are apprehen­sive about traveling to the ships except when weather conditions are favorable and fishing is poor in other areas_ The return of log books by this group has been the largest shortcoming of this study. This is partly due to complacency on the • 14 part of recreational fishermen and partly due to inclement weather. • Although hurricane Anita did not hit Port Aransas, almost all boats were removed from the water and boating activity from August 28 through Labor Day has been virtually nonexistent. Consequently, it • has been difficult to reach recreational fishermen and prod them into returning log books. To date 12% of the log books have been returned • • Much of the original impetus to construct the Liberty Ship reefs came from sport diving interest generating petitions to the Texas I Coastal and Marine Council in support of this project• Not surpris­• ingly, this same group has been one of the most frequent users of the reefs. Recording individual recreational diver usage of the reefs is • extremely difficult as there is no central dock or launching area through which they can be monitored. Consequently, most diver usage was monitored through dive shops in the Corpus Christi area, see• Table V. It became immediately apparent from all people interviewed that the Liberty Ship reefs are an important new resource for rec­reational divers• • s. Charter Diving Groups Table V • Dive Charter Groups Participating in Survey CHARTER ORGANTZATION RESPONDENT UTILIZATION! • Copeland's Dive Shop Saundra Copeland 2 Padre Island Dive Shop Pat McMillan 64 • • 15 CHARTER ORGANIZATION RESPONDENT· · UTTLI·ZATIONl Oceaneers Dive Shop 12 Frenchie(Charter Boat) Bill Beaudreau 3 lutilization is expressed as total boat-days fished during the • .three-month study period There are three dive shops in the Corpus Christi area, and all of them have begun charter services to the reef. They vary in the • numbers of divers they accommodate per trip and the frequency of trips to the reefs. One dive shop operates trips on a per individual basis as do party fishing boats. A trip is scheduled and advertised • and anyone wishing to go may register until the trip is full. They generally carry 50-60 divers per charter and made two trips during they survey period. The other shops and private charter boats • generally handle small groups that organize among themselves and charter the boat as a group. These shops average six divers per trip and make more frequent trips. One shop ran 12 charters, the • other 64 during the three-month study period. 15% of the divers surveyed used the Liberty Ships for spearfishing with the remainder of the divers involved in photography or viewing. The total number • of trips recorded from this user group was 85. The average expen­ diture by each diver was $36.42 and the total recorded expenditures were $15,080.00. All respondents indicated that they intended to • continue running charters to the Liberty Ships during other seasons. • III. BIOLOGY OF SELECTED FISH SPECIES INHABITING THE LIBERTY SHIP REEFS Fishermen were asked to report the five most commonly encountered • • 16 species on the Liberty Ships during the study period. These species were: barracuda (Sphyraena barracuda), ling (Rach centron canadum), king mackerel (Scomberomorus cavalla) , red snapper (Lutjanus campechanus), and Warsaw grouper (Epinephelus nigritus). The rela­• tive abundance of different species landed by anglers may be as much a reflection of the methods employed as it is of the actual abun­ dance of the species. A complete list of species taken by anglers • or sighted by divers is included in Table VI • Table VI Fish species taken by angles or sighted by SCUBA divers on the Liberty Ships Reefs during the months of June, July and August • COMMON NAME SCIENTIFIC NAME • Red Snapper Lutjanus campechanus Warsaw Grouper Epinephelus nigritus Jewfish Epinephelus itajara • Spadefish Chaetodipterus· faber Angelfish Pomacanthus paru Spanish mackerel Scomberomorus macuTatus· · King Mackerel Scomberomorus cavall-a • Bonito Euthynnus. alletteratus Dolphin Coryphaena hippuris Sailfish Istiophorus platypterus • Ling Rachycentron canadum Barracuda Sphyraena barracuda Redfish Sciae·nops· oce·ll.ata • • 17 ' COMMON NAME SCI-ENTTFTC NAME • Sandtrout Cynoscion arenarius Atlantic Croaker Whiting • Crevalle Jack Sheepshead Sergeant Major Moonfish Pinfish Damselfishes Butterflyfishes Squirrelfish Tarpon Micropogon undulatus Menticirrhus americanus Caranyx hippos Archosargus probatocephalus Abudefduf saxatilis Varner setapinnis Lagodon rhomdoides Pomacentridae Chaetodontidae Holocentrus· ~· Megalops atlantica • The following is a brief description of the five most common species. 1. Red Snapper (Lutjanus campechanus) • In the Gulf of Mexico red snapper is one of the most valuable and sought after species by both commercial and recreational inter­ests. Bromberg (1973) reported red snapper ranked fourth in popu­• larity after trout, snook and grouper by recreational boats and first by commercial sportfishing boats. The interest in red snapper as a sport fish is not nearly as great in South Texas as in other • Gulf States. Unlike other areas of the Gulf, recreational landings of red snapper do not exceed commercial landings. The reason for this in the Port Aransas area is probably the distance of suitable • snapper banks from shore. Hospital Rock, the nearest available reef, is located 38 miles off Port Aransas. This is outside the safe • • 18 operating range of most recreational boats under any but the most • ideal weather conditions. The Liberty Ships have provided a red snapper fishing area that is accessible to small boat operators; however, sportfishermen need to be made more aware of this new re­ • source and should be encouraged to bottomfish as a new form of offshore sportfishing. One of the rationales for placing all the ships in one area • was to concentrate enough reef habitat to support a breeding self­ supporting population of red snapper instead of merely attracting and concentrating snapper from other areas. • Recent studies on the life history of red snapper indicate that red snapper are not nearly as territorial as previously believed (Moe, 1963; Johnson et al., 1976). Red snapper move away • from outcroppings to sandy featureless bottoms to spawn (Moe, 1963) • The planktonic eggs are subject to dispersal over wide areas and are able to colonize outcroppings other than those of their parents. • Although the self-sustaining idea may be simplistic, there is good evidence that the Liberty Ships are already supporting a true resident population of red snapper. Both sexes are present and all • size classes except young of the year have been reported. The smallest red snapper recorded was 20 cm and the largest was 18 lbs. Most fish caught off the ships weighed approximately 1 lb. According• to age-growth studies (Mosley, 1965), these fish are age class 2, spawning class l+. This indicates that most of the population is capable of reproducing. The absence of juveniles (<20cm) does not I indicate that the reefs are not self-sustaining. Juveniles frequent open sandy and muddy bottoms away from outcroppings and bottom irreg­ • • 20 • 2. Warsaw Grouper (Epinephe·lUS· nigritus) . The Warsaw grouper is a seasonal resident on the Liberty Ship • reefs. This species is more temperate in its distribution than other groupers and prefers cooler waters. Unfortunately, this study was begun just as Warsaw were migrating from the ships to deeper • cooler waters. Large catches of up to 700 lbs. were reported through the winter and spring prior to this study. Anglers landed individual grouper weighing over 150 lbs. on many occasions and divers reported grouper estimated visually at 300-400 lbs. • Due to their large maximum size and consequent fighting abili­ties, Warsaw are probably the main reason most anglers specifically . fish the Liberty Ships at other times of the year. Several charter boat operators indicated that they intended to rely on Warsaw fishing • trips for their income through the fall and winter season• Although there are few data.. on the life history or conunercial landings of Warsaw, it is doubtful that Warsaw • can withstand as intense fishing pressure as red snapper. Growth patterns determined for a similar species, Epinephalus morio (the red grouper), indicate that spawning does not occur until after five years of age (Moe, 1963) I • and that the species may reach 30 years of age. Moe cautions that long-lived slow growing species such the grouper are more as sus­ceptible to population reduction through fishing pressure than short­ • lived faster growing species such as the red snapper. Since fishing pressure is light in offshore areas, there may be sufficient stock to replenish the reefs through seasonal migrations. • Several Warsaw were landed in June before they had migrated completely from the reefs. Four Warsaw stomachs were examined to • • 21 determine dietary preferences. In general they consumed small • invertebrates and schooling fish that may have been drawn to the • reefs. In three of four fish, penaeid shrimp averaging 10 cm constituted 69% of the stomach contents. The remaining 31% con­sisted of small (8-10 cm) school fish, primarily rough scad (Trachurus, lathami), and Gulf butterfish (Peprilus burti). Although • most of the Warsaw stomachs contained numerous small prey items, • they are capable of taking large items also. The stomach of one • 45 lb. warsaw contained a fish head, poss.ibly a ling (Rachycentron canadum), that completely filled a 2,000 ml beaker. In addition, the fish contained 200 ml of other fish remains and a callapa crab• This same individual contained a large hook and about 2 feet of • monofilament leader. The hook was completely overgrown with a layer of stomach epithelium and apparently had little effect on the fish judging from outward appearances of health. • 3. Barracuda (Sphyraena barracuda), Barracuda are primarily a tropical species that inhabit the Liberty Ship Reefs only during the warmer months. They were ex­ tremely abundant on the reefs during the study and also constituted , • one of the major complaints about the reefs. In general they are strongly attracted to underwater structures such as artificial reefs and drilling rigs. On the Liberty Ship reefs they commonly occupy • the midwater zone above the ships but below the surface• Barracuda rely on vibrations emitted by struggling or wounded prey to stimulate feeding behavior (Bohlke and Chaplin, 1968). • Consequently, they are difficult to hook using dead baits or lures • Most anglers encounter barracuda while attempting to land other fish• • -·-·-·­ • 22 • The barracuda is attracted to the struggling fish and responds by attacking it. When the original fish is eventually boated it is often completely ruined. I have inspected several catches of king­fish from the Liberty Ships where the majority of the catch consisted • of heads and body pieces • • In other areas of the Gulf and Caribbean, barracuda are consid­ered a worthy sportfish that is actually sought and whose flesh is considered edible. In this area of Texas, barracuda are considered despoilers of normal sportfishing and their absence is greatly ap­ preciated. The flesh is considered marginally edible at best. • Consequently, no barracuda were brought to the fish cleaning areas that I monitored and no stomachs were obtained. I can foresee no solution to the barracuda problem on the reefs • as they co-occur during the warmer months with kingfish. The best alternative would be to demonstrate methods of catching barracuda and encour~ging anglers to pursue ~barracuda as a legitimate sportfish. · • 4. Kingfish (Scomberomorus cavallo)· • Kingfish or king mackerel are "perhaps the most popular offshore gamefish in the northeastern Gulf of Mexico, where the appearance of kingfish is regarded as the marine harbinger of summer" (Moore and Hoese, 1977}. This aptly describes the position of this species in the recreation and economics of the Port Aransas area. Kingfish are • a highly migratory member of the tuna and mackerel family (Scombridae) that appear off the Texas coast during the sununer months. They apparently follow a continuous migratory path from sununer feeding • areas off Texas and Mexico to winter grounds off Florida. This pattern has been recently substantiated by tag returns. A kingfish • • 23 tagged in Port Mansfield during August of 1976 was recovered the • following winter from Florida. In the course of this s~udy, a tag was recovered from a kingfish tagged in Key West, Florida, in February, 1977 and recovered from Port Aransas in August of 1977~ • It is apparent that bottom structures such as the Liberty Ship reefs can do little to enhance the overall abundance of such a pelagic migratory species. However, the increased supply of ·forage • fish may tend to concentrate them. Kingfish occupy the upper water column over the Liberty Ships where they are caught by people drift fishing or trolling from the • surface to a depth of 30 feet. Although kingfish are common to the ships, no one surveyed indicated that the reefs were unusually pro­ductive of this species or that the area was superior to any other • area. Most boats interviewed averaged about five kingfish per trip. Increased productivity may be possible by enhancing the fish-attracting capabilities of the reefs through the emplacement of floating mid­• water structures as described by Ogren (1974). These structures tend to draw small pelagic schooling fish and consequently, pelagic predators in the same way as bottom structures draw small benthic • forage fish. Most anglers fish a variety of places on the way to and from the reefs; hence, it is impossible to identify which of the catch • came from the Liberty Ships. Consequently, no kingfish stomachs were examined from fish definitely from the reefs. 5. Ling (Rachycentron canadum) . • Ling do not school as do most other pelagic sportfish. They are most often found alone or in small groups of up to five individ­ • • 24 • uals (Bohlke and Chaplin, 1968}. · For this reason anglers do not usually fish specifically for ling but catch them incidentally with • other species, primarily kingfish. Although they are caught inci­dentally, they are highly regarded as a food fish. Ling are also migratory, occurring off Port Aransas from April • to November (Springer and Pearson, 1958} • For this reason their absolute numbers are probably not enhanced by artificial reefs. Ling are strongly attracted to any object in the water column such as floating debris, or • anchored boats, buoys, drilling rigs arti­ficial reefs. The Liberty Ships probably concentrate ling to some degree. However, this could be greatly enhanced by the addition of midwater or surface structures such as additional mooring buoys. Few ling stomachs were obtained because anglers usually brought • in mixed catches from several places. Two stomachs were examined; one was empty; the other (an unusually large 32 lb. specimen) contained one fish, a midshipman (Porichthys poro-s-issirnus) 10 cm long. • Randall (1968) indicated that ling depend heavily on crabs, shrimp, and other benthic invertebrates commonly found around the Liberty Ships • • • • • • IV. SUMMARY. AND SUGGEST·IONS • 1. The utilization of the Liberty Ship reefs by recreational fishermen during the months of· June, July and August was not as heavy as might be expected due to the nature of the summer • sportfishery off Port Aransas, Texas. Anglers· pursue p~lagic species, primarily kingfish, while the reefs are designed primarily to increase populations of benthic species• • 2. Recreational divers extensively utilized the reefs for spearfishing, photography and viewing. All dive shops in the area have organized charter services to the reefs • • 3. Although fishing pressure was low during the summer months, fishermen indicated that they intended to rely heavily on the • reefs from September through April when most pelagic species migrate from the area. Warsaw grouper and red snapper are the primary species sought during the cooler months • • • 4. Examination of stomach contents of Wars.aw grouper and red snapper revealed small invertebrates, primarily penaeid shrimp and portunid crab, were the mainstay of their diet. The abun­ dance of this type of prey item is probably enhanced by the Liberty Ship substrate• • s. The outer two ships, without marker buoys, are probably underutilized because smaller boats without depth recorders are unable to find them. Many divers and boat operators have • requested that buoys be-placed on the other two ships • • • • 6. The fishing success of anglers using the Liberty Ship reefs and consequently, their opinions of the value of the ships is, to a large extent, determined by their knowledge of how to fish an artificial reef and how to fish for new species. The • success of many recreational anglers could be improved by publication of proper techniques for anchoring around reefs and methods of fishing for Warsaw grouper, red snapper and under­ • utilized pelagic species, such as barracuda• • • • • • • • • 27 ' BIBLIOGRAPHY • • Bromberg, K. M. 1973. Determination of the number of com­mercial and non-commercial recreational boats in the United States, their use and selected characteristics. Final Report, NMFS Contract # 3-35490 to Information Concepts Inc., III pp. Distributed by NTIS, u. s. Department of • Commerce, Washington, D. c. Bohlke, J. E. and c. G. Chaplin, 1968. Fishes of the Bahamas, Livingston Publishing Company, Wynnewood, PA. • Buchanan, D. C. 1973. Effects of an artificial habitat on the • marine sport fishery and economy of Murrells Inlet, South Carolina. Marine Fisheries Review, vol. 125, No. 9. 15-22. Futch, R. B. and G. E. Bruger. 1976. Age. growth and Reproduc­ • tion of red snapper in Florida waters. Contribution No. 275, Florida Dept. of Natural Resources, Marine Research Laboratory. St. Petersburg, Florida• • Johnson, J. R., J. K. Adams and R. Foster. 1976. The red snapper resource of the Texas continental shelf. In Bullis and Jones {ed) Proceedings: Coloquium on snapper grouper fishery resources of the Western Central Atlantic Ocean. Florida Sea Grant Program. Rep. No. 17~ • Miles, D. w. 1949. A study of food habits of the fishes of the • Aransas Bay area. M. s. thesis, University-of Texas at Austin. 70 pp. Moe, M. A., Jr.-1963. A survey of offshore fishing in Florida• Florida Board of Conservation. Marine Lab. Prof. Par. Ser. No. 4, 117'pp • • • • Moore, R. H. and H. D. Hoese. 1977~ Fishes of the Gulf of Mexico, Texas A & M University Press, College Station, • Texas. 327 · pp. Mosley, F. N. 1965. Biology of the red snapper, Lutj·anus aya Bloch, of the northwestern Gulf of Mexico. M. s. thesis • University of Texas, Austin, Texas. 53 pp. Ogren, L. H. 1974. Midwater structures for enhancing recrea­tional fishing. In Proceedings: Artificial Reef Conference, Center for Marine Resources, Texas A & M University. Pub. No. TAMU-SG-74-103. • Randall, J. E. 1968. Caribbean Reef Fishes. T. F. H. Puhl • Jersey City, New Jersey. Springer, v. G. and J. Pirson. Fluctuations in the relative • abundances of sportfishes as indicated by the catch at Port Aransas, Texas. 1952-56 Publ. Marine Science Institute, University of Texas. 5: 169-185• • • • • •