EFFECT OF FRESHWATER INFLOW ON MACROBENTHOS PRODUCTIVITY AND NITROGEN LOSSES IN TEXAS ESTUARIES Paul A. Montagna, Principal Investigator TWDB Contract No. 99-483-267 Technical Report Number TR/99-01 October 1999 FINAL REPORT EFFECT OFFRESHWATER INFLOWONMACROBENTHOS PRODUCTIVITY AND NITROGEN LOSSES IN TEXAS ESTUARIES by Paul A. Montagna, Principal Investigator from University ofTexas at Austin Marine Science Institute 750 Channelview Drive Port Aransas, Texas 78373 to Texas Water Development Board P.O. Box 13231, Capital Station 1700 N. Congress Ave., Rm. 462 Austin, TX 78711-3231 Interagency Cooperative Contract TWDB Contract No. 99-483-267 The University ofTexas Marine Science Institute Technical Report Number TR/99-01 October 1999 TABLE OF CONTENTS LIST OF FIGURES Hi PREFACE v LIST OF CONTRIBUTIONS vi Scientific Publications vi Technical Reports vi Oral Presenetations vi ACKNOWLEDGMENTS vii INTRODUCTION 1 METHODS 2 Study Design and Area 2 Hydrographic Measurements 3 Geological Measurements 3 Biological Measurements 4 Sediment Nitrogen Measurements 4 Station Locations 5 RESULTS 6 Hydrographic Data 6 Nutrient Concentrations 8 Biomass Data 9 Species Data 20 Sediment Elemental Composition in Upper Laguna Madre 38 Average Vertical Distribution ofElemental Content (%) among Stations 40 DISCUSSION 41 Conditions in Current Sampling Year 41 44 Long-Term Change in Benthos 49 Benthic Response in Current Sampling Year I Nitrogen Losses CONCLUSION REFERENCES REVIEW LETTER FROM TWDB 53 65 68 II LISTOF FIGURES Figure 1. The Texas Coastal Bend lagoonal estuaries with major rivers, tidal inlets, and station locations 3 Figure 2. Salinity change at stations in Lavaca-Colorado Estuary during the sampling period . 42 Figure 3. Salinity change at stations in Guadalupe Estuary during the sampling period 43 Figure 4. Macrofauna biomass change at stations in Lavaca-Colorado Estuary during the sampling period 45 Figure 5. Macrofauna abundance change at stations in Lavaca-Colorado Estuary during the sampling period 46 Figure 6. Macrofauna biomass change at stations in Guadalupe Estuary during the sampling period 47 Figure 7. Macrofauna abundance change at stations in Guadalupe Estuary during the sampling period 48 Figure 8. Long-term macrofauna biomass and salinity change in Lavaca-Colorado Estuary. Estuarine-wide average for stations A-D 51 Figure 9. Long-term macrofauna abundance and salinity change in Lavaca-Colorado Estuary. Estuarine-wide for stations A-D average 52 Figure 10. Long-term macrofauna biomass and salinity change in Guadalupe Estuary. Estuarine- wide for stations A-D 53 average Figure 11. Long-term macrofauna abundance and salinity change in Guadalupe Estuary. Estuarine-wide for stations A-D 54 average 12. Figure Long-term salinity change in the Lavaca-Colorado and Guadalupe Estuaries. Estuarine-wide for stations A-D 55 average Figure 13. Long-term salinity change and dissolved inorganic nitrogen (DIN) change in the Lavaca-ColoradoEstuary. Quarterlyestuarine-wideaverageforstationsA-D 56 Figure 14. Long-term salinity change and dissolved inorganic nitrogen (DIN) change in the Guadalupe Estuary. Quarterly estuarine-wide average for stations A-D 57 - Figure 15.NitrogencontentofUpperLagunaMadre BaffinBaysediments 59 - Figure 16. CarboncontentofUpperLagunaMadre BaffinBaysediments 60 - Figure 17, Average nitrogen and carbon content in Upper Laguna Madre Baffin Bay sediments 6l - Figure 18. Profile ofnitrogen (6 ISN) isotope values in Upper Laguna Madre Baffin Bay sediments 62 - Figure 19. Profile ofcarbon (6 13C) isotope values in Upper Laguna Madre Baffin Bay III sediments 63 Figure 20. Average ofnitrogen (6 15N)and carbon (6 l3C)isotope values in Upper Laguna Madre - Baffin Bay sediments 64 IV PREFACE The current contract period is a continuation ofa long-term study with the goal to determine the importance of freshwater inflow in maintaining productivity in Texas estuaries. Previous work has been performed with support, or partial support, by the Texas Water Development Board, Water Research Planning Fund, authorized under the Texas Water Code sections 15.402 and 16.058(e). This support was administered by the Board under interagency cooperative contract numbers: (1986-87) 0757, 8-483-607, 9-483-705, 90-483-706, 91-483-787, 92-483-300, 93-483-352, 94-483-003, 95-483-068, 96-483-132, 97-483-199, 98-483-233, and most recently 99-483-267. This is an iterative report, much like the Texas Parks and Wildlife, Data Management Series. Data is added to the time series, and the whole time series is reported so that year-to-year comparisons can be made. The report has several sections. First, all contributions that acknowledged the Texas Water Development Board for support during the current project (99 483-267)arereported. Thesecontributionsrepresenttheproductsoftheresearchproject. Second,isacompilationofbiological andhydrographical dataobtained overthecourseofthe study. Third, is a compilation ofthe sediment data on nitrogen losses that has been collected during the contract period. V LIST OF CONTRIBUTIONS For current year’s contract Scientific Publications 1999. Ritter, M.C. and P.A. Montagna. Seasonal hypoxia and models ofbenthic response in a Texas bay. Estuaries 22:7-20. Twilley, R.R., J. Cowan, T. Miller-Way, P.A. Montagna and B Mortazavi. 1999. Benthic nutrientfluxesinselectedestuariesintheGulfofMexico. In:Bianchi, T.S.,Pennock, J.R. and R. Twilley, BiogeochemistryofGulfofMexico Estuaries. John Wiley& Sons, Inc. Pp. 163 -209. Technical Reports Montagna, P.A. 1998. Effect offreshwater inflow on macrobenthos productivity and nitrogen losses in Texas estuaries. Final report to Texas Water Development Board, Contract No. 98-483-233, University ofTexas Marine Science Institute Technical Report Number TR/98-03, Port Aransas, Texas. 61 pp. OralPresentations (*lnvitedseminars) *Montagna, P.A. “Texas Lagoonal Estuaries.” Benthos ofCoastal Seas Workshop, supported by the National Science Foundation (NSF) and the Luso-American Foundation (FLAD), April 18-21 1999, Lisbon, Portugal. Montagna, P.A. “Using benthic infauna data to assess risk” American Society ofLimnology and Oceanoraphy, Santa Fe, New Mexico. February 1 -5, 1999. VI ACKNOWLEDGMENTS I must acknowledge the significant contributions ofMr. Rick Kalke. Rick began the first samplingstudyofLavacaBayin1984. Heisanoutstandingfieldpersonand taxonomist. The Carrol Simanek also work reported on in this study could not have been performed without him. provided significant help in data management. We obviously are collecting and processing a large amount of data. Input, proof-reading and maintenance ofthis large data set is a daunting task that Carrol handles well. Dr. Steve Jarvis, Mr. Robert Burgess, Mr. Chris Kalke aided in field very collections. This work has also benefitted by discussions with colleagues at the Texas Water Development Board (TWDB), e.g., William Longley, David Brock, and Gary Powell who have provided much help and guidance. other projects. The most interesting trend is that have moved from monitoring and evaluating The Texas estuarine research reported here has been supplemented by many we freshwater inflows to using diverted, restored, or returned inflows to enhanceand restore wetland areas of estuaries. Two such projects are currently under way. The US. Bureau ofReclamation has funded studies on the effect offreshwater diversion to Rincon Bayou to restore the Nueces DeltaMarsh. TheCityofCorpusChristihasfunded abiologicalmonitoringprogramofthe AllisonWasteWaterTreatmentPlantdiversionprojecttorestorean areaoftheNuecesDelta Marsh with returned inflows. In these studies, we have built on past information and used the TWDB long-term data set in Nueces Bay as a baseline for comparisons. VII INTRODUCTION The primary goal ofthe current research program is to define quantitative relationships between marine resource populations and freshwater inflows to the State’s bays and estuaries. However, we know there is year-to-year variability in the population densities and successional eventsofestuarinecommunities. Thisyear-to-yearvariabilityisapparentlydrivenbylong-term, and global-scale climatic events, e.g., El Nino, which affects rates of freshwater inflow. Therefore, this report documents long-term changes in populations and communities that are influenced by freshwater inflow. The best indicator ofproductivity is the change in biomass ofthe community over time. Asecondarygoalofthecurrentresearch istoquantifylossofnitrogeninTexasestuaries. Nitrogen is the key element limiting productivity. A simple budget would account for nitrogen entering the bay via freshwater inflow, how it is captured and transformed into biomass, and One aspect ofnitrogen loss is very poorly understood: finally how it is lost from the ecosystem. How much nitrogen is buried in sediments and lost from the system? We report here nitrogen content changes with respect to sediment depth. Presumably nitrogen is labile in the upper, biologically active, layers ofsediment and refractory at depth. Therefore, it is important to determinethesedimentdepthatwhich nitrogencontentisatalowandconstantvalue. This study is a continuation offreshwater inflow studies that began in 1984. The goals have evolved the years to reflect the synthesis ofnew information and the management needs over were ofthe Texas Water Development Board (TWDB). The original studies (1984-1986) designed to determine the effect ofinflow on Lavaca Bay. One station used during that study is still being sampled. San Antonio Bay was studied in 1987, and the Nueces Estuary (Nueces and Corpus Christi Bays) were studied in 1988. Long-term studies ofthe Lavaca-Colorado and Guadalupe Estuaries began in 1990. Our initial conclusions based on one to four years of data were that inflow does increase benthic productivity (Kalke and Montagna, 1991; Montagna and Kalke, 1992; 1995). However, later analysis ofthe data set over a 5-year period demonstrated that the largest effect may not be on productivity, but may be on community structure (Montagna and Li, 1996). This implies that reduced inflows may not only reduce productivity but may also change the composition ofspecies in an estuary. The complete long-term record now extends over nine years. The completion ofthis research will take 12 to 20 years, because the trends are driven by long-term climatic events controlled by global climate patterns, e.g, El Nino. 1 METHODS Study Design andArea There are seven major estuarine systems along the Texas coast. Each system receives drainage from one to three major rivers. The northeastern most estuaries receive more freshwater inflow than the southwestern estuaries. Twoestuarine systems were studied in detail (Fig. 1). Both systems have similar freshwater inflow characteristics, but the Lavaca-Colorado Estuary has directexchangeofmarinewaterwiththeGulfofMexicoviaPassCavallo, whereasthe Guadalupe Estuary does not. To assess ecosystem-wide variability stations in the freshwater influenced and marine influenced zones were chosen. Two stations, which replicate each ofthe two treatment effects (freshwater and marine) influence, were sampled. Generally these stations werealongthemajoraxisoftheestuarine system leadingfromrivermouthtothefootofthe estuary near the barrier island. This design avoids pseudoreplication, where only one station has thecharacteristicofthemaineffect, anditisnotpossibletodistinguishbetweenstation differences and treatment differences. The Lavaca River empties into Lavaca Bay, which is connected to Matagorda Bay. Matagorda Bay also has freshwater input from the Colorado and Tres Palacios River. Over a 47yearperiod( 1941-1987) theLavaca-Colorado Estuaryreceived of3.800x109 m 3y'1 an average withastandarddeviationof2.080 m3y"1(3.080±1.686xjQ6ac-fty' 1)offreshwaterinput,and the freshwater balance (input-output) 3.392xl09 m 3 y'1 with a standard deviation of was 91 61 2.345xl0m 3 y (2.750 ± 1.901 xioac-ft y* ) (TDWR, 1980a; TWDB unpublished data). Four Stations were occupied along the axis ofthe system. Two stations were in Lavaca Bay(AandB),andtwostationswereinMatagordaBay(CandD)(Fig.3). Depthsofstations A, B, C, and D were 1.3 2.0 m, 3.1 m, and 4.2 m, respectively. Four field trips were performed. StationAinLavacaBaywasthesamestation85sampledin1984-1986(Jonesetal., 1986). The San Antonio River joins the Guadalupe River that flows into San Antonio Bay. m, Over a 46-year period the Guadalupe Estuary received an average of2.896 x 109 m 3 y*1 with a standard deviationof1.597m3y'1(2.347±1.295x106ac-fty' 1)offreshwaterinput,andthefreshwater balance (input-output) was 2.624 x 109 m 3 y'1 with a standard deviation of 1,722 x 109 m 3 y’1 (2.127 ±1.396xio6ac-fty' 1)(TDWR, 1980b;TWDBunpublisheddata). Thissystemwasstudiedfrom January through July 1987 and sampling commenced again in 1990. Four stations were occupied; freshwater influenced stations at the head of the bay (station A) and at mid-bay (station B), and two marine influenced stations near the Intracoastal Waterway 2 at the southwestern foot of the bay (station C) and one at the southeastern foot of the bay (station D) (Fig. 1). Stations were sampled five times in the first year. one All stations were in shallo stations A, B, C, and D were 1.3 m, 1.9 m, 2.0 m, and 1.6 m, respectively. Hydrographic Measurements Salinity, conductivity, temperature, pH, dissolved oxygen, and redox potential were measured at the surface and bottom at each station during each sampling trip. Measurements were made by lowering a probe made by Hydrolab Instruments. Salinities levels are automatically corrected to 25 °C. The manufacturer states that the of accuracy salinity measurements are 0.1 ppt. When the Hydrolab instrument was not working, water samples were collected fromjust beneaththe surface and from the bottom in jars, and refractometer readings were made at the surface. Figure 1. The Texas Coastal Bend lagoonal estuaries with major rivers, tidal inlets, and station locations. Geological Measurements Sediment grain size analysis was also performed. Sediment core samples were taken by diver and sectioned at depth intervals 0-3 cm and 3-10 cm. Analysis followed Percent contribution by weight was measured for four components: rubble (e.g. shell hash), sand, silt, and clay. A2O cm3 sediment sample was mixed with 50 ml ofhydrogen peroxide and 75 ml of deionized water standard geologic procedures (Folk, 1964; E. W. Behrens, personal communication). to digest organic material in the sample. The sample was wet sieved through a 62 pm mesh stainless steel screen using a vacuum pump and a Millipore Hydrosol SST filter holder to separate rubble and sand from silt and clay. After drying, the rubble and sand were separated on a 125 pm screen. The silt and clay fractions were measured using pipette analysis. Biological Measurements Sediment was sampled with core tubes held by divers. The macrofauna were sampled withatube6.7cmindiameter,andsectionedatdepthintervalsof0-3cmand3-10cm. Three replicatesweretakenwithina2mradius. Sampleswerepreservedwith5%bufferedformalin, sieved on 0.5 mm mesh screens, sorted, identified to the lowest taxonomic level possible, and counted. Each macrofauna sample was also used to measure biomass. Individuals were combined into higher taxa categories, i.e., Crustacea, Mollusca, Polychaeta, Ophiuroidea, and all other taxa were placed together in one remaining sample. Samples were dried for 24 h at 55 °C, and weighed. Before drying, mollusks were placed in 1 N HCI for 1 min to 8 h to dissolve the carbonate shells, and washed with fresh water. Sediment Nitrogen Measurements All Texas estuaries have been studied. The Sabine-Neches and Trinity-San Jacinto Estuaries were sampled in 1993. The Lavaca-Colorado and Guadalupe Estuaries were sampled in 1990, and resampled in 1992. The Nueces Estuary and Baffin Bay were sampled in 1991. Our approach is to take sediments cores and measure nitrogen changes with respect to sediment depth Cores are taken to a depth of 1 m. One-cm sediment sections are taken at the depth intervals listed. The sediment is dried, ground up, and homogenized. Carbon and nitrogen content, as a percent dry weight ofsediment, is measured using a CHN analyzer. Station Locations Estuary Station Latitude (N) Longitude (W) 4 Lavaca-Colorado A B C D E F 28.40.439 28.38.192 28.32.482 28.28.661 28.33.162 28.35.767 96.34.950 96.34.985 96.28 082 96.17,230 96.12.558 96.02.456 Guadalupe A B C D 28.23.611 28.20.866 28.14.920 28.18.126 96.46.344 95.44.744 96.45.619 96.41.061 Upper Laguna Madre 189 135 27.20.994 27.26.983 97.23.543 97.20.437 Baffin Bay 6 24 27.16.605 27.15.833 97.25.655 97.33.085 5 RESULTS Hydrographic Data Hydrographic measurements. Abbreviations: STA=Station, Z=Depth, SAL(R)=Salinity by refractometer, SAL(M)=Salinity by meter, COND=Conductivity, TEMP=Temperature, DO=dissolved oxygen, and ORP=oxidation redox potential. Missing values show with a period. Lavaca-Colorado Estuary Date STA z SAL(R) SAL(M) COND TEMP pH DO ORP 06JUL98 A 0.00 18 20.8 33.40 29.16 8.60 6.91 0.189 06JUL98 A 1.30 18 20.9 33.50 29.17 8.60 6.91 0.191 06JUL98 B 1.90 20 23.3 37.30 29.24 8.70 6.98 0.195 06JUL98 C 0.00 25 27.8 43.20 29.57 8.58 7.57 0.187 06JUL98 C 3.00 25 28.0 43.20 29.67 8.56 6.72 1.910 06JUL98 D 0.00 28 29.8 45.90 29.69 8.69 7.68 0.187 06JUL98 D 4.10 28 30.9 47.40 29.64 8.58 6.70 0.193 06JUL98 E 0.00 27 29.0 44.80 29.85 8.36 7.95 0.181 06JUL98 E 3.40 27 29.0 44.80 29.66 8.60 7.32 0.189 06JUL98 F 0.00 25 27.4 42.60 30.01 8.32 6.97 0.189 06JUL98 F 1.30 25 27.5 42.70 29.57 8.45 5.90 0.191 120CT98 A 0.00 5 4.3 8.40 25.07 7.76 7.44 0.232 120CT98 A 1.50 5 7.4 13.72 25.02 7.66 6.20 0.239 120CT98 B 0.00 7 7.0 12.73 24.68 8.02 8.77 0.221 120CT98 B 2.20 7 12.1 20.70 25.36 7.80 6.30 0.230 120CT98 C 0.00 15 15.4 25.50 25.61 8.06 8.55 0.221 120CT98 C 3.10 15 24.5 38.50 25.69 7.93 6.41 0.229 120CT98 D 0.00 22 21.9 34.80 25.78 8.09 8.48 0.216 120CT98 D 4.20 22 31.4 48.20 26.70 7.85 5.85 0.222 120CT98 E 0.00 20 19.7 31.80 25.74 8.09 8.90 0.206 120CT98 E 3.30 20 29.8 46.00 26.49 7.72 3.11 0.221 120CT98 F 0.00 14 14.0 23.50 25.95 7.88 8.83 0.195 120CT98 F 1.20 14 21.2 34.20 25.25 7.46 1.47 0.216 05JAN99 A 0.00 12 14.3 24.00 7.88 8.23 10.33 0.179 05JAN99 A 1.20 12 15.1 24.80 8.73 8.24 9.85 0.180 05JAN99 B 0.00 7 12.2 20.70 7.25 8.32 10.60 0.178 05JAN99 B \ 1.70 7 20.0 32.40 9.06 8.29 9.21 0.183 05JAN99 C 0.00 16 20.6 33.10 9.52 8.23 9.28 0.177 05JAN99 C 2.50 16 22.8 36.20 10.17 8.22 8.58 0.179 05JAN99 D 0.00 20 22.6 35.90 9.93 8.27 9.05 0.176 05JAN99 D 3.70 20 29.2 45.20 12.63 8.15 7.65 0.180 05JAN99 E 0.00 17 19.0 30.70 9.38 8.39 9.64 0.177 05JAN99 E 2.80 17 19.3 31.20 9.11 8.38 9.13 0.178 05JAN99 F 0.00 7 10.0 17.00 9.04 8.44 10.66 0.180 05JAN99 F 0.70 7 16.4 26.70 9.12 8.36 8.45 0.185 06APR99 A 0.00 10 12 7 21.50 21,89 8.17 7.40 0.161 06APR99 A 1.20 12 9 21.80 22.00 8.18 7.34 0.168 6 06APR99 B 0.00 14 16.0 26.60 22.20 8.28 7.39 0.180 06APR99 B 2.10 16.5 27.00 22.23 8.23 6.83 0.186 06APR99 C 0.00 22 24.4 38.40 22.57 8.18 6.83 0.190 06APR99 C 3.10 24.5 38.60 22.55 8.18 6.45 0.187 06APR99 D 0.00 25 26.6 41.50 22.36 8.29 7.17 0.183 06APR99 D 4.40 27.1 42.20 22.40 8.30 6.73 0.186 06APR99 E 0.00 23 25.1 39.40 22.74 8.37 8.08 0.190 06APR99 E 3.60 26.4 41.30 22.39 8.24 5.89 0.196 06APR99 F 0.00 15 16.7 27.40 23.21 8.22 8.42 0.189 06APR99 F 1.40 16.8 27.60 23.20 8.33 7.93 0.189 Guadalupe Estuary Date STA z SAL(R) SAL(M) COND TEMP pH DO ORP 07JUL98 A 0.00 3 5.0 9.35 29.78 8.92 07JUL98 A 1.10 3 12.7 21.70 29.41 7.54 07JUL98 B 0.00 12 13.3 22.50 29.66 7.85 07JUL98 B 1.60 12 13.8 23.30 29.41 6.24 . 07JUL98 C 0.00 22 24.7 38.80 29.53 7.49 07JUL98 C 1.80 22 25.5 40.10 29.44 7.10 07JUL98 D 0.00 13 14.6 24.30 29.29 . 7.74 2.700 07JUL98 D 1.40 13 14.7 24.50 29.24 7.39 130CT98 A 1.20 2 2.1 4.66 25.90 6.30 130CT98 B 0.00 . 5 4.6 8.82 26.86 9.31 130CT98 B 1.60 5 9.3 16.10 25.57 6.07 130CT98 C 0.00 14 13.2 22.30 26.00 . 7.84 130CT98 C 2.00 14 13.8 23.10 25.94 6.11 130CT98 D 0.00 18 18.3 29.70 25.77 . 6.93 130CT98 D 1.60 18 18.3 29.70 25.76 6.93 130CT98 E 0.00 20 20.5 32.90 25.78 7.25 130CT98 E 2.30 20 21.2 33.90 25.76 7.07 130CT98 F 0.00 14 13.9 23.30 26.67 7.38 130CT98 F 1.40 14 17.5 28.60 26.55 5.82 06JAN99 A 0.00 0 0.0 0.85 12.96 8.34 9.72 0.203 06JAN99 A 0.70 0 0.0 0.88 10.11 8.34 10.21 0.205 06JAN99 B 0.00 0 0.2 1.47 11.50 8.59 10.95 0.196 06JAN99 B 1.20 0 2.0 4.56 8.99 8.45 10.46 0.205 06JAN99 C 0.00 0 1.3 3.30 11.67 8.65 12.40 0.194 06JAN99 C 1.50 0 4.9 9.49 9.02 8.44 10.17 0.205 06JAN99 D 0.00 4 5.4 10.07 10.22 7.63 11.57 0.171 06JAN99 D 1.10 4 11.6 20.30 9.46 7.87 10.58 0.184 07APR99 A 0.00 2 3.5 7.00 24.79 8.60 07APR99 A 1.40 3.6 7.30 24.72 8.21 07APR99 B 0.00 8 9.3 16.30 24.30 8.46 07APR99 B 1.80 11.4 19.20 24.30 6.70 07APR99 C 0.00 11 13.5 22.70 23.99 8.14 07APR99 C 2.10 13.6 22.90 23.92 7.71 07APR99 D 0.00 14 15.2 25.20 23.81 8.47 07APR99 D 1.60 16.7 27.60 23.63 7.56 7 Nutrient Concentrations Nutrient measurementstake during sampling. Water depth is in m. Nutrient concentrations are in umol/l. Lavaca-Colorado Estuary Date Station Depth PO, SI04 N0 2 N0 3 NH., 06JUL98 A 0 0.671 53 0.224 0.000 0.744 06JUL98 A 1.3 0.503 26 0.167 0.000 0.193 06JUL98 B 0 0.336 40 0.216 0.000 0 240 06JUL98 B 1.9 0.336 35 0.444 0.000 0.619 06JUL98 C 0 0.252 24 0.186 0.000 0.273 06JUL98 C 3 0.235 23 0.192 0.000 0.321 06JUL98 D 0 0.235 23 0.167 0.000 0.116 06JUL98 D 4.1 0.218 16 0.141 0.000 0.132 06JUL98 E 0 0.185 23 0.222 0.000 0.148 06JUL98 E 3.4 0.235 22 0.228 0.000 0.133 06JUL98 F 0 0.889 81 1.198 2.807 2.026 06JUL98 F 1.3 1.376 70 1.257 2.489 3.477 120CT98 A 0 2.305 161 3.437 8.358 2.378 120CT98 A 1.5 2.357 148 3.928 6.728 4.101 120CT98 B 0 0.418 140 2.626 3.167 1.236 120CT98 B 2.2 1.112 126 2.838 1.610 3.077 120CT98 C 0 0.847 97 0.234 0.000 1.082 120CT98 C 3.1 0.667 57 0.511 0.000 1.157 120CT98 D 0 0.541 66 0.208 0.000 0.912 120CT98 D 4.2 0.416 23 0.763 0.581 0.684 120CT98 E 0 0.656 80 0.192 0.000 0.574 120CT98 E 3.3 1.074 41 0.898 0.000 1.676 120CT98 F 0 2.156 112 0.509 5.388 0.859 120CT98 F 1.2 3.128 101 1.236 4.661 4.113 05JAN99 A 0 1.134 63 0.325 0.944 1 500 05JAN99 A 1.2 1.250 64 0.412 0.162 1.579 05JAN99 B 0 1.130 66 0.292 1.177 1.321 05JAN99 B 1.7 0.922 69 0.286 0.000 1.400 05JAN99 C 0 1.073 75 0.197 0.000 1 547 05JAN99 C 2.5 1.417 67 0.750 0.000 2.067 05JAN99 D \ 0 1.885 68 0.319 0.000 2.180 05JAN99 D 3.7 0.975 30 0.541 0.913 2.530 05JAN99 E 0 1.074 40 0.214 0.000 1.595 05JAN99 E 2.8 1.129 36 0.353 0.000 1.607 05JAN99 F 0 2.078 28 0.461 12.57 1.484 05JAN99 F 0.7 2.703 26 0.921 6.454 2.983 06APR99 A 0 0.870 94 0.547 4.540 1.817 06APR99 A 1.2 1.003 82 0.578 4.388 5.355 06APR99 B 0 0.747 76 0.399 1.013 2.529 06APR99 B 2.1 0.880 56 0.793 1,692 3.697 06APR99 C 0 1.013 22 0.670 0,650 2,428 8 06APR99 C 3.1 1.790 24 1.956 2.376 4.375 06APR99 D 0 0.604 11 0.312 0.168 1.853 06APR99 D 4.4 0.491 9 0.299 0.060 1.735 06APR99 E 0 0.604 11 0.318 0.367 1.685 06APR99 E 3.6 1.92.3 14 1.903 0.453 3.768 06APR99 F 0 1.125 43 0.787 13.09 2.058 06APR99 F 1.4 1.739 49 0.994 15.00 2.719 Guadalupe Estuary Date Station Depth P0 4 SI0 4 NQ2 N0 3 NH4 07JUL98 A 0 2.181 159 0.157 0.326 0.421 07JUL98 A 1.1 2.349 129 0.164 0.000 0.942 07JUL98 B 0 2.181 108 0.219 0.000 0.278 07JUL98 B 1.6 2.383 107 0.374 0.000 0.641 07JUL98 C 0 0.503 79 0.175 0.000 0.072 07JUL98 C 1.8 0.671 79 0.223 0.000 0.230 07JUL98 D 0 2.517 116 0.204 0.000 0.103 07JUL98 D 1.4 1.510 61 0.168 0.000 0.009 120CT98 A 0 7.427 116 1.826 37.64 3.164 120CT98 A 1.2 7.398 100 2.027 39.44 3.510 120CT98 B 0 4.978 146 0.796 16.37 1.055 120CT98 B 1.6 ' 4.919 132 0.850 12.62 1.418 120CT98 C 0 2.616 147 0.221 0.000 0.951 120CT98 C 2 2.605 146 0.464 0.000 1.331 120CT98 D 0 1.293 115 0.332 0.000 1.055 120CT98 D 1.6 1.311 115 0.282 0.000 0.951 120CT98 E 0 0.680 85 0.170 0.000 0.847 120CT98 E 2.3 0.745 83 0.277 0.000 0.830 120CT98 F 0 2.604 141 0.142 0.000 0.968 120CT98 F 1.4 2.479 132 0.448 0.000 1.418 06JAN99 A 0 3.158 102 0.525 69.73 2.864 06JAN99 A 0.7 3.836 154 0.478 67.58 5.480 06JAN99 B 0 2.110 101 0.320 40.82 0.912 06JAN99 B 1.2 2.612 66 0.563 24.53 1.499 06JAN99 C 0 2.816 133 0.301 29.69 0^686 06JAN99 C 1.5 2.608 38 0.471 9.735 1.509 06JAN99 D 0 2.679 27 0.490 14.33 1.812 06JAN99 D 1.1 2.042 31 0.411 3.701 1.654 07APR99 A 0 4.491 135 1.441 59.82 1.080 07APR99 A 1.4 4.992 160 1.570 57.34 0.894 07APR99 B 0 2.486 62 0.376 32.33 0.842 07APR99 B 1.8 2.046 64 0.363 19.68 2.044 07APR99 C 0 1.831 94 0.624 10.23 4.058 07APR99 C 2.1 1.841 67 0.632 10.85 1.942 07APR99 D 0 1.422 77 0 474 3.160 1.483 07APR99 D 1.6 1.422 74 0.5.38 0.000 2.652 Biomass Data 9 Biomassismeasuredfortaxonomicgroupings. Number(n)ofindividualsandbiomass(mg)for each vertical section within a replicate core. Lavaca-Colorado Estuary Date Station Replicate Section Taxa n mg 06JUL98 A 1 3 Polychaeta 15 0.69 06JUL98 A 1 10 Polychaeta 29 6.41 06JUL98 A 2 3 Mollusca 1 0.03 06JUL98 A 2 3 Polychaeta 15 2.08 06JUL98 A 2 10 Polychaeta 23 5.68 06JUL98 A 3 3 Crustacea 1 0.01 06JUL98 A 3 3 Mollusca 3 0.56 06JUL98 A 3 3 Polychaeta 29 2.04 06JUL98 A 3 10 Polychaeta 18 2.79 06JUL98 B 1 3 Polychaeta 10 0.57 06JUL98 B 1 10 Polychaeta 7 1.48 06JUL98 B 2 3 Mollusca 1 0.02 06JUL98 B 2 3 Polychaeta 12 1.17 06JUL98 B 2 10 Polychaeta 5 0.85 06JUL98 B 3 3 Mollusca 1 0.03 06JUL98 B 3 3 Polychaeta 10 1.29 06JUL98 B 3 10 Polychaeta 6 0.96 06JUL98 C 1 3 Crustacea 1 0.02 06JUL98 C 1 3 Mollusca 3 2.41 06JUL98 C 1 3 Rhynchocoela 1 0.1 06JUL98 C 1 3 Polychaeta 3 1.44 06JUL98 C 1 3 Sipunculida 1 0.12 06JUL98 C 1 10 Rhynchocoela 1 0.45 06JUL98 C 1 10 Polychaeta 13 5.85 06JUL98 C 2 3 Crustacea 1 0.01 06JUL98 C 2 3 Mollusca 1 0.02 06JUL98 C 2 3 Rhynchocoela 2 0.04 06JUL98 C 2 3 Polychaeta 4 2.16 06JUL98 C 2 10 Mollusca 1 0.02 06JUL98 C 2 10 Polychaeta 13 9.51 06JUL98 C 3 3 Mollusca 2 0.33 06JUL98 C 3 3 Polychaeta 9 3.88 06JUL98 C 3 10 Polychaeta 8 4.87 06JUL98 D 1 3 Polychaeta 6 18.92 06JUL98 D 1 10 Polychaeta 1 0.01 06JUL98 D 2 3 Mollusca 1 0.29 06JUL98 D 2 3 Rhynchocoela 1 0.01 06JUL98 D 2 3 Polychaeta 4 0.15 06JUL98 D 2 10 Crustacea 2 1.18 06JUL98 D 2 10 Mollusca 1 4.79 06JUL98 D 2 10 Rhynchocoela 5 3.08 06JUL98 D 2 10 Ophiuroidca 1 11.05 06JUL98 D 2 10 Polychaeta 9 2.47 10 06JUL98 D 3 3 Crustacea 1 2.68 06JUL98 D 3 3 Polvchacta 2 0.03 06JUL98 D 3 3 Sipunculida 1 0.92 06JUL98 D 3 10 Mollusca 1 0.09 06JUL98 D 3 10 Ophiuroidca 1 5.2 06JUL98 D 3 10 Polvchacta 2 20.78 06JUL98 E 1 3 Mollusca 1 0.1 06JUL98 E 1 3 Polvchacta 2 0.43 06JUL98 E 1 10 Polvchacta 3 0.65 06JUL98 E 2 3 Polvchacta 0 0 06JUL98 E 2 10 Polvchacta 3 0.8 06JUL98 E 3 3 Polvchacta 2 0.52 06JUL98 E 3 10 Ophiuroidca 1 1.1 06JUL98 E 3 10 Polvchacta 4 0.33 06JUL98 F 1 3 Crustacea 1 0.07 06JUL98 F 1 3 Rhynchococla 1 0.06 06JUL98 F 1 3 Polvchacta 24 1.85 06JUL98 F 1 10 Rhynchococla 1 0.08 06JUL98 F 1 10 Polvchacta 7 0.57 06JUL98 F 2 3 Mollusca 1 0.07 06JUL98 F 2 3 Rhynchococla 1 0.3 06JTJL98 F 2 3 Polvchacta 11 0.57 06JUL98 F 2 10 Mollusca 1 0.14 06JUL98 F 2 10 Rhynchococla 1 0.16 06JUL98 F 2 10 Polvchacta 8 1.03 06JUL98 F 3 3 Polvchacta 13 0.52 06JUL98 F 3 10 Polvchacta 4 0.31 120CT98 A 1 3 Polvchacta 17 4.59 120CT98 A 1 10 Polvchacta 21 5.14 120CT98 A 2 3 Polvchacta 10 1.96 120CT98 A 2 10 Rhynchococla 1 2.77 120CT98 A 2 10 Polvchacta 14 4.02 120CT98 A 3 3 Crustacea 1 0.04 120CT98 A 3 3 Polvchacta 10 0.96 120CT98 A 3 10 Polvchacta 43 8.97 120CT98 B 1 3 Polvchacta 7 3.62 120CT98 B 1 10 Polvchacta 19 3.03 120CT98 B 2 3 Polvchacta 13 1.59 120CT98 B 2 10 Rhynchococla I 0.02 120CT98 B 2 10 Polvchacta 17 3.91 120CT98 B . 3 3 Polvchacta 23 1.79 120CT98 B 3 10 Polvchacta 7 1.71 120CT98 C I 3 Mollusca 2 1.39 120CT98 C I 3 Polvchacta 21 1.02 120CT98 C I 10 Polvchacta 11 7.66 120CT98 C 2 3 Polvchacta 14 0.48 120CT98 C 2 10 Polvchacta 9 4.33 120CT98 C 3 3 Mollusca 1 0.03 120CT98 C 3 3 Polvchacta 27 1.25 120CT98 C 3 10 Rhynchococla 1 0.1 120CT98 C 3 10 Polvchacta 15 2.92 11 120CT98 D 1 3 Mollusca 1 0.08 120CT98 D 1 3 Polychaeta 12 0.3 120CT98 D 1 10 Mollusca 4 0.14 120CT98 D 1 10 Rhynchococla 2 1.94 120CT98 D 1 10 Polychaeta 2 0.11 120CT98 D 2 3 Crustacea 13 0.55 120CT98 D 2 3 Polychaeta 8 0.33 120CT98 D 2 10 Crustacea 2 2.34 120CT98 D 2 10 Mollusca 5 0.38 120CT98 D 2 10 Ophiuroidea 1 5.96 120CT98 D 2 10 Polychaeta 12 0.77 120CT98 D 3 3 Crustacea 1 0.02 120CT98 D 3 3 Rhynchocoela 2 0.03 120CT98 D 3 3 Polychaeta 11 0.34 120CT98 D 3 10 Mollusca 10 0.39 120CT98 D 3 10 Rhynchocoela 1 2.98 120CT98 D 3 10 Ophiuroidea 1 20.79 120CT98 D 3 10 Polychaeta 12 1.01 120CT98 E 1 3 Polychaeta 21 1.09 120CT98 E I 10 Polychaeta 76 7.76 120CT98 E 2 3 Polychaeta 24 0.64 120CT98 E 2 10 Polychaeta 8 4.39 120CT98 E 3 3 Mollusca 2 0.02 120CT98 E 3 3 Rhynchocoela 1 0.02 120CT98 E 3 3 Polychaeta 20 0.96 120CT98 E 3 10 Polychaeta 34 6.96 120CT98 F 1 3 Other 1 0.02 120CT98 F 1 3 Polychaeta 9 0.75 120CT98 F 1 10 Polychaeta 4 0.21 120CT98 F 2 3 Polychaeta 2 0.08 120CT98 F 2 10 Polychaeta 2 0.09 120CT98 F 3 3 Polychaeta 13 0.37 120CT98 F 3 10 Polychaeta 3 0.14 05JAN99 A 1 3 Rhynchocoela 1 0.64 05JAN99 A 1 3 Polychaeta 19 2.6 05JAN99 A 1 10 Polychaeta 0 0 05JAN99 A 2 3 Polychaeta 14 1.28 05JAN99 A 2 10 Polychaeta 0 0 05JAN99 A 3 3 Polychaeta 16 2.4 05JAN99 A 3 10 Polychaeta 2 0.61 05JAN99 B 1 3 Mollusca 1 0.03 05JAN99 B 1 3 Rhynchocoela 1 0.15 05JAN99 B 1 3 Polychaeta 3 0.26 05JAN99 B 1 10 Polychaeta 0 0 05JAN99 B 2 3 Polychaeta 10 1.06 05JAN99 B 2 10 Rhynchococla 1 0.08 05JAN99 B 3 3 Rhynchocoela 1 0.4 05JAN99 B 3 3 Polychaeta 4 0.49 05JAN99 B 3 10 Polychaeta 0 0 05JAN99 C 1 3 Mollusca 2 0.09 05JAN99 C 1 3 Polychaeta 14 1.57 12 05JAN99 C I 10 Rhynchocoela 2 1.85 05JAN99 C 1 10 Polychaeta 10 3.48 05JAN99 C 2 3 Mollusca 3 0.26 05JAN99 C 2 3 Polychaeta II 0.61 05JAN99 C 2 10 Polychaeta 11 6.59 05JAN99 C 3 3 Rhynchocoela 1 0.3 05JAN99 C 3 3 Polychaeta 3 0.21 05JAN99 C 3 10 Rhynchocoela 1 0.15 05JAN99 C 3 10 Polychaeta 12 2.44 05JAN99 D 1 3 Mollusca 2 0.07 05JAN99 D 1 3 Other 1 0.01 05JAN99 D 1 3 Polychaeta 10 0.22 05JAN99 D 1 10 Crustacea 2 0.85 05JAN99 D 1 10 Mollusca 2 0.04 05JAN99 D I 10 Rhynchocoela 3 3.7 05JAN99 D 1 10 Ophiuroidea 1 1.44 05JAN99 D 1 10 Polychaeta 10 16.31 05JAN99 D 2 3 Crustacea 2 0.3 05JAN99 D 2 3 Mollusca 4 0.09 05JAN99 D 2 3 Polychaeta 15 0.27 05JAN99 D 2 10 Crustacea 4 2.22 05JAN99 D 2 10 Mollusca 23 0.96 05JAN99 D 2 10 Rhynchocoela 1 2.56 05JAN99 D 2 10 Ophiuroidea 1 7.94 05JAN99 D 2 10 Polychaeta 17 10.11 05JAN99 D 3 3 Mollusca 1 0.01 05JAN99 D 3 3 Polychaeta 8 0.8 05JAN99 D 3 10 Mollusca 4 0.12 05JAN99 D 3 10 Ophiuroidea 1 8.11 05JAN99 D 3 10 Polychaeta 9 2.52 05JAN99 E I 3 Polychaeta 11 0.47 05JAN99 E 1 10 Polychaeta 7 8 05JAN99 E 2 3 Crustacea 1 0.01 05JAN99 E 2 3 Rhynchocoela 1 0.23 05JAN99 E 2 3 Polychaeta 6 0.37 05JAN99 E 2 10 Polychaeta 8 4.53 05JAN99 E 3 3 Rhynchocoela 1 0.09 05JAN99 E 3 3 Polychaeta 20 0.61 05JAN99 E 3 10 Rhynchocoela 1 1.41 05JAN99 E 3 10 Polychaeta 13 4.95 05JAN99 F 1 3 Polychaeta 39 2.38 05JAN99 F 1 10 Polychaeta 9 1.26 05JAN99 F 2 3 Polychaeta 28 1.19 05JAN99 F 2 10 Polychaeta 1 0.22 05JAN99 F 3 3 Crustacea I 0.01 05JAN99 F 3 3 Mollusca 1 0.03 05JAN99 F 3 3 Polychaeta 29 1.59 05JAN99 F 3 10 Polychaeta 3 0.85 06APR99 A I .3 Crustacea 1 0.01 06APR99 A 1 3 Rhynchocoela 2 0.17 13 06APR99 A 1 3 Polychacta 5 0.15 06APR99 A 1 10 Polychaeta 1 0.24 06APR99 A 2 3 Rhynchococla 3 1.77 06APR99 A 2 3 Polychacta 17 2.5 06APR99 A 2 10 Rhynchococla 1 0.74 06APR99 A 2 10 Polychaeta 8 5.58 06APR99 A 3 3 Mollusca 1 0.03 06APR99 A 3 3 Rhynchococla 1 0.05 06APR99 A 3 3 Polychacta 11 2.43 06APR99 A 3 10 Polychaeta 3 0.27 06APR99 B 1 3 Rhynchococla 1 0.11 06APR99 B 1 3 Polychaeta 6 0.99 06APR99 B 1 10 Polychaeta 1 0.08 06APR99 B 2 3 Crustacea 1 0.04 06APR99 B 2 3 Mollusca 1 0.11 06APR99 B 2 3 Polychaeta 9 0.17 06APR99 B 2 10 Rhynchococla 1 0.17 06APR99 B 2 10 Polychaeta 7 14 06APR99 B 3 3 Crustacea 1 0.01 06APR99 B 3 3 Polychaeta 11 2.13 06APR99 B 3 10 Polychaeta 4 1.53 06APR99 C 1 3 Polychaeta 1 0.21 06APR99 C 1 10 Polychaeta 1 0.08 06APR99 C 2 3 Polychaeta 1 0.07 06APR99 C 2 10 Polychaeta 6 1.01 06APR99 C 3 3 Crustacea 1 0.02 06APR99 C 3 3 Polychaeta 1 0.07 06APR99 C 3 10 Polychaeta 3 0.21 06APR99 D 1 3 Crustacea 2 0.07 06APR99 D 1 3 Mollusca 3 1.51 06APR99 D 1 3 Polychaeta 3 0.22 06APR99 D 1 10 Crustacea 2 1.51 06APR99 D 1 10 Mollusca 6 2.77 06APR99 D 1 10 Rhynchococla 1 1.16 06APR99 D 1 10 Ophiuroidea 1 6.63 06APR99 D 1 10 Polychaeta 15 25.73 06APR99 D 2 3 Crustacea 49 1.8 06APR99 D 2 3 Hemicordata 1 0.08 06APR99 D 2 3 Mollusca 1 0.42 06APR99 D 2 3 Rhynchococla 1 0.03 06APR99 D 2 3 Polychacta 7 0.35 06APR99 D 2 10 Crustacea 32 3.29 06APR99 D 2 10 Mollusca 6 0.88 06APR99 D 2 10 Rhynchococla 2 1.24 06APR99 D 2 10 Other 1 0.17 06APR99 D 2 10 Ophiuroidea 2 21.38 06APR99 D 2 10 Polychacta 16 0.77 06APR99 D 3 3 Crustacea 25 0.5 06APR99 D 3 3 Hemicordata 3 1.14 06APR99 D 3 3 Mollusca 3 1 52 06APR99 D 3 3 Other 1 0 2 14 06APR99 D 3 3 Ophiuroidca 1 0.02 06APR99 D 3 3 Polychaeta 5 3.75 06APR99 D 3 10 Crustacea 26 3.15 06APR99 D 3 10 Mollusca 7 0.62 06APR99 D 3 10 Rhynchococla 1 0.35 06APR99 D 3 10 Ophiuroidca 1 6.38 06APR99 D 3 10 Polychaeta 2 1.31 06APR99 E 1 3 Hemicordata 3 1.16 06APR99 E I 3 Polychaeta 5 0.69 06APR99 E 1 10 Polychaeta 8 2.51 06APR99 E 2 3 Crustacea 2 9.89 06APR99 E 2 3 Hemicordata 3 0.33 06APR99 E 2 3 Other 1 0.16 06APR99 E 2 3 Polychaeta 5 0.24 06APR99 E 2 10 Hemicordata 1 1.05 06APR99 E 2 10 Ophiuroidca 1 3.5 06APR99 E 2 10 Polychaeta 12 4.51 06APR99 E 3 3 Hemicordata 6 1.82 06APR99 E 3 3 Mollusca 1 0.05 06APR99 E 3 3 Rhynchococla 1 0.04 06APR99 E 3 3 Other 1 0.02 06APR99 E 3 3 Polychaeta 7 0.4 06APR99 E 3 10 Hemicordata 1 0.37 06APR99 E 3 10 Mollusca 2 1.12 06APR99 E 3 . 10 Other 1 0.21 06APR99 E 3 10 Polychaeta 9 1.97 06APR99 F 1 3 Crustacea 7 0.71 06APR99 F 1 3 Polychaeta 32 4.28 06APR99 F 1 10 Mollusca 1 0.09 06APR99 F I 10 Polychaeta 5 0.58 06APR99 F 2 3 Crustacea 10 0.68 06APR99 F 2 3 Polychaeta 29 2.77 06APR99 F 2 10 Polychaeta 25 3.48 06APR99 F 3 3 Crustacea 2 0.16 06APR99 F 3 3 Mollusca 1 0.02 06APR99 F 3 3 Polychaeta 25 2.11 06APR99 F 3 10 Rhynchococla 1 0.14 06APR99 F 3 10 Polychaeta 22 2.97 Guadalupe Estuary Date Station Replicate Section Taxa n mg 07JUL98 A 1 3 Crustacea 1 0.05 07JUL98 A 1 3 Mollusca 46 11.94 07JUL98 A 1 3 Polychaeta 10 0.61 07JUL98 A 1 10 Mollusca 1 0.07 07JUL98 A 1 10 Polychaeta 3 2.85 07JUL98 A 2 3 Crustacea 2 0.08 07JUL98 A 2 3 Chironomid larvae 1 0,05 15 07JUL98 A 2 3 Mollusca 61 24.59 07JUL98 A 2 3 Polychacta 5 0.19 07JUL98 A 2 10 Polychacta 1 0.11 07JUL98 A 3 3 Cmstacca 3 0.18 07JUL98 A 3 3 Mollusca 27 16.54 07JUL98 A 3 3 Polychacta 6 0.2 07JUL98 A 3 10 Mollusca 1 0.11 07JUL98 B 1 3 Crustacea 1 0.14 07JUL98 B 1 3 Mollusca 9 1.68 07JUL98 B 1 3 Rhynchocoela 1 0.09 07JUL98 B I 3 Polychacta 29 3.4 07JUL98 B 1 10 Polychacta 0 0 07JUL98 B 2 3 Mollusca 6 0.04 07JUL98 B 2 3 Polychacta 17 2.94 07JUL98 B 2 10 Polychacta 2 0.18 07JUL98 B 3 3 Mollusca 17 2.97 07JTJL98 B 3 3 Polychacta 15 0.64 07JUL98 B 3 10 Polychacta 20 5.94 07JUL98 C 1 3 Crustacea 1 0.02 07JUL98 C 1 3 Mollusca 3 0.46 07JUL98 C 1 3 Polychacta 26 1.66 07JUL98 C 1 10 Mollusca 1 0.05 07JUL98 C 1 10 Polychacta 11 1.65 07JUL98 C 2 3 Mollusca 4 0.78 07JUL98 C 2 3 Polychacta 18 1.67 07JUL98 C 2 10 Polychacta 3 0.51 07JUL98 C 3 3 Crustacea 2 0.02 07JUL98 C 3 3 Mollusca 5 0.85 07JUL98 C 3 3 Polychacta 40 1.74 07JUL98 C 3 10 Polychacta 11 1.81 07JUL98 D 1 3 Crustacea 1 0.05 07JUL98 D 1 3 Mollusca 1 0.02 07JUL98 D 1 3 Polychacta 14 1.35 07JUL98 D 1 10 Polychaeta 5 0.84 07JUL98 D 2 3 Crustacea 1 0.01 07JUL98 D 2 3 Polychaeta 18 1.03 07JUL98 D 2 10 Polychaeta 5 2.19 07JUL98 D 3 3 Polychaeta 13 1.04 07JUL98 D 3 10 Rhynchocoela 1 4.76 07JUL98 D 3 10 Polychaeta 5 0.32 130CT98 A I 3 Crustacea 1 1.72 130CT98 A 1 3 Mollusca 8 3.61 130CT98 A 1 3 Polychaeta 7 0.34 130CT98 A 1 10 Polychacta 2 1.53 130CT98 A 2 3 Mollusca 6 7.7 130CT98 A 2 3 Rhynchocoela 1 0.07 130CT98 A 2 3 Polychaeta 16 1.09 130CT98 A 2 10 Rhynchocoela 1 0.21 130CT98 A 2 10 Polychacta 3 1 71 130CT98 A 3 3 Mollusca 7 1.2 130CT98 A 3 3 Rhynchocoela 1 10.1 16 130CT98 A 3 3 Polychaeta 17 0.78 130CT98 A 3 10 Polychaeta 0 0 130CT98 B 1 3 Polychaeta 19 3.04 130CT98 B 1 10 Polychaeta 13 2.1 130CT98 B 2 3 Mollusca 5 1.15 130CT98 B 2 3 Polychaeta 25 4.97 130CT98 B 2 10 Polychaeta 5 1.74 130CT98 B 3 3 Mollusca 3 3.23 130CT98 B 3 3 Polychaeta 12 4.19 130CT98 B 3 10 Polychaeta 12 3.35 130CT98 C 1 3 Crustacea 1 0.02 130CT98 C 1 3 Mollusca 2 1.23 130CT98 C 1 3 Polychaeta 20 0.56 130CT98 C 1 10 Rhynchocoela 1 0.2 130CT98 C 1 10 Polychaeta 9 1.81 130CT98 C 2 3 Polychaeta 23 0.53 130CT98 C 2 10 Polychaeta 18 1.84 130CT98 C 3 3 Mollusca 1 0.07 130CT98 C 3 3 Polychaeta 28 1 130CT98 C 3 10 Rhynchocoela 1 14.24 130CT98 C 3 10 Polychaeta 4 0.15 130CT98 D 1 3 Crustacea 1 0.02 130CT98 D 1 3 Polychaeta 8 0.64 130CT98 D 1 10 Crustacea 3 0.08 130CT98 D 2 3 Mollusca 1 0.04 130CT98 D 2 3 Polychaeta 7 0.35 130CT98 D 2 10 Polychaeta 2 1.46 130CT98 D 3 3 Crustacea 1 0.02 130CT98 D 3 3 Rhynchocoela 1 0.37 130CT98 D 3 3 Other 1 0.09 130CT98 D 3 3 Polychaeta 13 0.72 130CT98 D 3 10 Crustacea 2 0.03 130CT98 D 3 10 Polychaeta 4 0.09 130CT98 E 1 3 Rhynchocoela 1 0.1 130CT98 E 1 3 Polychaeta 12 2.88 130CT98 E 1 10 Rhynchocoela 1 0.86 130CT98 E 1 10 Polychaeta 4 1.94 130CT98 E 2 3 Rhynchocoela 1 0.03 130CT98 E 2 3 Polychaeta 10 0.85 130CT98 E 2 10 Polychaeta 5 3.27 130CT98 E . 3 3 Polychaeta 3 0.33 130CT98 E 3 10 Polychaeta 3 1.98 130CT98 F 1 3 Crustacea 1 0.03 130CT98 F 1 3 Mollusca I 0.18 130CT98 F I 3 Polychaeta 26 0.71 130CT98 F 1 10 Mollusca 2 1 130CT98 F 1 10 Rhynchocoela 1 0.34 130CT98 F 1 10 Ophiuroidea 1 6.58 130CT98 F 1 10 Polychaeta 12 4.62 130CT98 F 2 3 Polychaeta 2 0.08 130CT98 F 2 10 Polychaeta 12 15.56 17 130CT98 F 3 3 Polychacta 10 18 130CT98 F 3 10 Polychacta 9 7.89 06JAN99 A 1 3 Chironomid larvae 1 0.03 06JAN99 A 1 3 Mollusca 15 4.86 06JAN99 A 1 3 Polychacta 2 0.09 06JAN99 A I 10 Polychacta 1 0.04 06JAN99 A 2 3 Mollusca 16 2.33 06JAN99 A 2 3 Polychacta 2 0.05 06JAN99 A 2 10 Polychacta 0 0 06JAN99 A 3 3 Mollusca 25 3.82 06JAN99 A 3 10 Rhynchocoela 1 0.17 06JAN99 A 3 10 Polychacta 1 0.03 06JAN99 B 1 3 Mollusca 16 2.76 06JAN99 B 1 10 Rhynchocoela 1 0.87 06JAN99 B 1 10 Polychacta I 0.06 06JAN99 B 2 3 Mollusca 6 1.03 06JAN99 B 2 3 Rhynchocoela 2 0.18 06JAN99 B 2 3 Polychacta 1 0.02 06JAN99 B 2 10 Rhynchocoela 2 0.71 06JAN99 B 2 10 Polychacta 4 0.2 06JAN99 B 3 3 Mollusca 10 1.87 06JAN99 B 3 3 Polychacta 8 0.44 06JAN99 B 3 10 Rhynchocoela 1 0.6 06JAN99 B 3 10 Polychacta 2 0.29 06JAN99 C 1 3 Polychacta 5 0.27 06JAN99 C I 10 Polychacta 0 0 06JAN99 C 2 3 Polychacta 13 0.34 06JAN99 C 2 10 Polychacta 2 0.14 06JAN99 C 3 3 Polychacta 7 0.24 06JAN99 C 3 10 Polychacta 1 0.06 06JAN99 D 1 3 Polychacta 11 0.22 06JAN99 D 1 10 Polychacta 0 0 06JAN99 D 2 3 Polychacta 17 0.43 06JAN99 D 2 10 Polychacta 0 0 06JAN99 D 3 3 Rhynchocoela 1 0.21 06JAN99 D 3 3 Polychacta 8 0.37 06JAN99 D 3 10 Polychacta 0 0 07APR99 A 1 3 Crustacea 2 10.44 07APR99 A 1 3 Chironomidlarvae 1 0.04 07APR99 A 1 3 Mollusca 17 2.52 07APR99 A I 3 Polychacta 3 0.95 07APR99 A 1 10 Chironomidlarvae 1 0.12 07APR99 A 1 10 Mollusca 4 0.56 07APR99 A 1 10 Polychacta 1 0.1 07APR99 A 2 3 Chironomid larvae 1 0.02 07APR99 A 2 3 Mollusca 15 4.97 07APR99 A 2 3 Polychacta 7 0.39 07APR99 A 2 10 Polychacta 0 0 07APR99 A 3 3 Crustacea 1 0.01 07APR99 A 3 3 Mollusca 15 3.02 07APR99 A 3 .3 Polychacta 1 0.05 18 07APR99 A 3 10 Chironomidlarvae 1 0.12 07APR99 A 3 10 Mollusca 1 0.17 07APR99 A 3 10 Polychacta 1 0.04 07APR99 B 1 3 Mollusca 11 186 07APR99 B 1 3 Rhynchococla 1 0.03 07APR99 B 1 3 Polychacta 6 0.7 07APR99 B 1 10 Rhynchococla 1 0.17 07APR99 B 2 3 Mollusca 3 0^69 07APR99 B 2 3 Polychacta 2 0.18 07APR99 B 2 10 Polychacta 1 0.1 07APR99 B 3 3 Mollusca 1 0.03 07APR99 B 3 3 Polychacta 3 0.38 07APR99 B 3 10 Polychacta 2 0.54 07APR99 C 1 3 Mollusca 3 0.65 07APR99 C 1 3 Polychacta 13 1.41 07APR99 C 1 10 Rhynchococla 1 0.08 07APR99 C I 10 Polychacta 6 0.57 07APR99 C 2 3 Mollusca 1 0.06 07APR99 C 2 3 Rhynchococla 1 0.02 07APR99 C 2 3 Polychacta 23 1.77 07APR99 C 2 10 Rhynchococla 1 0.72 07APR99 C 2 10 Polychacta 14 1.4 07APR99 C 3 3 Mollusca 2 0.54 07APR99 C 3 3 Polychacta 12 0.86 07APR99 C 3 10 Polychacta 13 1.53 07APR99 D 1 3 Polychacta 22 1.28 07APR99 D I 10 Polychacta 1 19.03 07APR99 D 2 3 Crustacea 17 0.24 07APR99 D 2 3 Polychacta 25 1.78 07APR99 D 2 10 Crustacea 3 0.07 07APR99 D 2 10 Polychacta 3 0.49 07APR99 D 3 3 Polychacta 20 1.65 07APR99 D 3 10 Polychacta 6 11.7 19 Species Data Number(n) ofindividuals ofmacrofauna species found at a vertical section depth within each replicate core. Lavaca-Colorado Estuary Date Station Replicate Section Species n 06JUL98 A 1 3 Slreblospio benedicti 5 06JUL98 A 1 3 Mediomastusambiseta 10 06JUL98 A 1 10 Mediomastusambiseta 29 06JUL98 A 2 3 Glycinde solitaria 1 06JUL98 A 2 3 Strcblospio benedicti 5 06JUL98 A 2 3 Mulinialateralis 1 06JUL98 A 2 3 Mediomastusambiseta 9 06JUL98 A 2 10 Parandaliaocularis 1 06JUL98 A 2 10 Mediomastusambiseta 22 06JXJL98 A 3 3 Streblospio benedicti 5 06JUL98 A 3 3 Ampclisca abdita 1 06JUL98 A 3 3 Littoridinasphinctostoma 3 06JUL98 A 3 3 Mediomastusambiseta 24 06JUL98 A 3 10 Mediomastusambiseta 18 06JUL98 B 13 Streblospio benedicti 1 06JUL98 B 13 Mediomastus ambiseta 9 06JUL98 B 1 10 Glycinde solitaria 1 06JUL98 B 1 10 Mediomastus ambiseta 6 06JUL98 B 2 3 Mulinia lateralis 1 06JUL98 B 2 3 Mediomastusambiseta 12 06JUL98 B 2 10 Mediomastusambiseta 5 06JUL98 B 3 3 Streblospio benedicti 1 06JUL98 B 3 3 Mulinia lateralis 1 06JUL98 B 3 3 Mediomastusambiseta 9 06JUL98 B 3 10 Mediomastus ambiseta 6 06JUL98 C 1 3 Rhynchocoela (unidentified) 1 06JUL98 C I 3 Glycinde solitaria 1 06JUL98 C I 3 Paraprionospio pinnata 1 06JUL98 C I 3 Maldanidae(unidentified) 1 06JUL98 C I 3 Mulinia lateralis 2 06JUL98 C 1 3 Tcllina sp. 1 06JUL98 C 1 3 Phascolion strombi 1 06JUL98 C 1 3 Mysidopsis bahia 1 06JUL98 C 1 10 Rhynchocoela (unidentified) 1 06JUL98 C 1 10 Lumbrineris parvapedata 2 06JUL98 C 1 10 Cossura delta 5 06JUL98 C 1 10 Mediomastusambiseta 6 06JUL98 C 2 3 Rhynchocoela (unidentified) 2 06JUL98 C 2 3 Lumbrineris parvapedata 1 06JUL98 C 2 3 Paraprionospio pinnata 3 06JUL98 C 2 3 Nuculana acuta 1 20 C 06JUL98 2 3 Monoculodes sp. 1 06JUL98 2 10 Palcanotus hcteroscta I C 06JUL98 C 2 10 Ancistrosyllis jonesi I 06JUL98 C 2 10 Ancistrosyllis papillosa I 06JUL98 C 2 10 Sigambra bassi 3 06JUL98 C 2 10 Cossura delta 3 06JUL98 C 2 10 Mysella planulata 1 06JUL98 C 2 10 Asychis elongata 1 06JUL98 C 2 10 Mcdiomastus ambiseta 3 06JUL98 C 3 3 Glycinde solitaria 2 06JUL98 C3 3 Paraprionospio pinnata 3 06JUL98 C33 1 Scoloplos texana 06JUL98 C 3 3 Mulinia lateralis 2 06JUL98 C 3 3 Mcdiomastusambiseta 3 06JUL98 C 3 10 Gyptis vittata 1 06JUL98 C 3 10 Lumbrinerisparvapedata 1 06JUL98 C 3 10 Paraprionospio pinnata 1 06JUL98 C 3 10 Cossura delta 2 06JUL98 C 3 10 Mcdiomastus ambiseta 3 06JUL98 D 1 3 Ancistrosyllis jonesi 1 06JTJL98 D 1 3 Paraprionospio pinnata 1 06JUL98 D 1 3 Minuspio cirrifera 1 06JUL98 D 1 3 Branchioasychis americana I 06JUL98 D 1 3 Mcdiomastus ambiseta 2 06JUL98 D 1 10 Gyptis vittata 1 06JUL98 D 2 3 Rltynchocoela (unidentified) 1 06JUL98 D 2 3 Gyptis vittata 1 06JUL98 D 2 3 Minuspio cirrifera 1 06JUL98 D 2 3 Corbula contracta I 06JUL98 D 2 3 Mcdiomastus ambiseta 2 06JUL98 D 2 10 Rhynchococla (unidentified) 5 06JUL98 D 2 10 Oligochaetes (unidentified) 5 06JUL98 D 2 10 Ancistrosyllis jonesi 1 06JUL98 D 2 10 Lumbrinerisparvapedata 1 06JUL98 D 2 10 Minuspio cirrifera 1 06JUL98 D 2 10 Cossura delta 1 06JUL98 D 2 10 Ophiuroidea (unidentified) 1 06JUL98 D 2 10 Apseudes sp. A 2 06JUL98 D 2 10 Pcriploma cf. orbiculare 1 06JUL98 D 3 3 Cossura delta 1 06JUL98 D 3 3 Ogyridcs limicola 1 06JUL98 D 3 3 Phascolion strombi 1 06JUL98 D 33 Mcdiomastus ambiseta 1 06JUL98 D 3 10 Diopatra cuprea I 06JUL98 D3 10 Pcriploma margaritaceum 1 06JUL98 D3 10 Pilargiidac (unidentified) 1 06JUL98 D3 10 Ophiuroidea (unidentified) I 06JUL98 E 1 3 Paraprionospio pinnata 1 06JUL98 E 1 3 Eulimostoma sp. 1 06JUL98 E 1 3 Mcdiomastus ambiseta 1 06JUL98 E 10 1 Sigambra tcnlaculata 1 21 06JUL98 E I It) Cossura delta 2 06JUL98 E 2 3 No species observed 0 06JUL98 E 2 10 Polydora caullcryi I 06JUL98 H 2 10 Paraprionospio pinnata 1 06JUL98 E 2 10 Cossura delta 1 06JUL98 E 3 3 Paraprionospio pinnata 1 06JUL98 E 3 3 Mediomastusambiseta 1 06JUL98 E 3 10 Polydora caulleryi 2 06JUL98 E 3 10 Minuspio cirrifcra I 06JUL98 E 3 10 Cossura delta 1 06JUL98 E 3 10 Ophiuroidea (unidentified) 1 06JUL98 F 1 3 Rhynchocoela (unidentified) 1 06JUL98 F 1 3 Paraprionospio pinnata 4 06JUL98 F 1 3 Edotea montosa 1 06JUL98 F 1 3 Mediomastus ambiseta 20 06JUL98 F 1 10 Rhynchocoela (unidentified) 1 06JUL98 F 1 10 Gyptis vittata 1 06JUL98 F 1 10 Mediomastusambiseta 6 06JUL98 F 2 3 Rhynchocoela (unidentified) 1 06JUL98 F 2 3 Caecum johnsoni 1 06JUL98 F 2 3 Mediomastusambiseta 11 06JUL98 F 2 10 Rhynchocoela (unidentified) 1 06JUL98 F 2 10 Paraprionospio pinnata 1 06JUL98 F 2 10 Cossura delta 1 06JUL98 F 2 10 Caecum johnsoni 1 06JUL98 F 2 10 Mediomastusambiseta 6 06JUL98 F 3 3 Paraprionospio pinnata 1 06JUL98 F 3 3 Mediomastus ambiseta 12 06JUL98 F 3 10 Gyptis vittata 1 06JUL98 F 3 10 Mediomastusambiseta 3 120CT98 A 1 3 Streblospio benedicti 5 120CT98 A 1 3 Mediomastusambiseta 12 120CT98 A 1 10 Mediomastus ambiseta 21 120CT98 A 2 3 Streblospio benedicti 6 120CT98 A 2 3 Mediomastus ambiseta 4 120CT98 A 2 10 Rhynchocoela (unidentified) I 120CT98 A 2 10 Mediomastusambiseta 14 120CT98 A 3 3 Streblospio benedicti 9 120CT98 A 3 3 Ostracoda (unidentified) 1 120CT98 A 3 3 Mediomastusambiseta I 120CT98 A 3 10 Streblospio benedicti 3 120CT98 A 3 10 Mediomastus ambiseta 40 120CT98 B 1 3 Streblospio benedicti 7 120CT98 B 1 10 Streblospio benedicti 6 120CT98 B 1 10 Mediomastusambiseta 13 120CT98 B 2 3 Streblospio benedicti 13 120CT98 B 2 10 Rhynchocoela (unidentified) 1 120CT98 B 2 10 Streblospio benedicti 3 120CT98 B 2 10 Mediomastusambiseta 14 120CT98 B 3 3 Streblospio benedicti 17 120CT98 B 3 3 Mediomastusambiseta 6 22 120CT98 B 3 10 Slrcblospio bencdicti 4 120CT98 B 3 10 Mcdiomastus ambiseta 3 120CT98 C 1 3 Diopatra cuprca I 120CT98 C I 3 Slrcblospio bencdicti 3 120CT98 C 1 3 Paraprionospio pinnata 1 120CT98 C 13 Maldanidae(unidentified) 1 120CT98 C I 3 Nuculana acuta 1 120CT98 C I 3 Actcocina canaliculata 1 120CT98 C 1 3 Mcdiomastus ainbiscta 15 120CT98 C I 10 Paraprionospio pinnata 1 120CT98 C 1 10 Spiochaetopterus costa rum 1 120CT98 C I 10 Haploscoloplos fragilis 1 120CT98 C I 10 Cossura delta 2 120CT98 C 1 10 Mcdiomastus ainbiscta 6 120CT98 C 2 3 Gyptis vittata 2 120CT98 C 2 3 Slrcblospio bencdicti 6 120CT98 C 2 3 Maldanidae (unidentified) 1 120CT98 C 2 3 Mcdiomastus ambiseta 5 120CT98 C 2 10 Lumbrineris parvapedata 1 120CT98 C 2 10 Paraprionospio pinnata 1 120CT98 C 2 10 Tharyx setigera 1 120CT98 C 2 10 Mcdiomastus ambiseta 6 120CT98 C 3 3 Streblospio benedicti 17 120CT98 C 3 3 Paraprionospio pinnata 1 120CT98 C 3 3 Nuculana acuta 1 120CT98 C 3 3 Mcdiomastus ambiseta 9 120CT98 C 3 10 Rhynchocoela (unidentified) 1 120CT98 C 3 10 Cossura delta 3 120CT98 C 3 10 Mcdiomastus ambiseta 12 120CT98 D 1 3 Streblospio benedicti 6 120CT98 D 1 3 Cossura delta 4 120CT98 D I 3 Periploma cf. orbiculare 1 120CT98 D 1 3 Mcdiomastus ambiseta 2 120CT98 D 1 10 Rhynchocoela (unidentified) 2 120CT98 D I 10 Periploma margaritaceum 4 120CT98 D 1 10 Mcdiomastus ambiseta 2 120CT98 D 2 3 Streblospio bencdicti 6 120CT98 D 2 3 Cossura delta I 120CT98 120CT98 D D 2 2 3 3 Apseudcs sp. A Mcdiomastus ambiseta 12 1 120CT98 D> 2 3 Eudorella sp. 1 120CT98 D 2 10 Oligochaetes (unidentified) 3 120CT98 D 2 10 Sigambra tentaculata 1 120CT98 D 2 10 Gyptis vittata 1 120CT98 D 2 10 Minuspio cirrifcra 6 120CT98 D 2 10 Periploma margaritaceum 5 120CT98 D 2 10 Ophiuroidca (unidentified) 1 120CT98 D 2 10 Apscudes sp. A 2 120CT98 120CT98 D D 2 3 10 3 Malmgrcniclla taylori Rhynchocoela (unidentified) 1 2 120CT98 D 3 3 Streblospio bencdicti 5 23 120CT98 D 3 3 Cossura delta 3 120CT98 D 3 3 Apseudes sp. A 1 120CT98 D 3 3 Mediomastusambiseta 3 120CT98 D 3 10 Rhynchococla (unidentified) I 120CT98 D 3 10 Oligochaetes (unidentified) 2 120CT98 D 3 10 Cossura delta 5 120CT98 D 3 10 Pcriploma margaritaceum 10 120CT98 D 3 10 Ophiuroidea (unidentified) 1 120CT98 D 3 10 Mediomastus ambiseta 4 120CT98 D 3 10 Malmgreniclla taylori 1 120CT98 E 1 3 Polydora caulleryi 8 120CT98 E 1 3 Streblospio benedicti 7 120CT98 E 1 3 Paraprionospio pinnata 1 120CT98 E 1 3 Spiochaetopterus costarum 1 120CT98 E 1 3 Cossura delta 3 120CT98 E 1 3 Mediomastusambiseta 1 120CT98 E 1 10 Sigambra tentaculata 1 120CT98 E 1 10 Gyptis viltata 1 120CT98 E 1 10 Glycinde solitaria 1 120CT98 E 1 10 Polydora caulleryi 60 120CT98 E 1 10 Paraprionospio pinnata 3 120CT98 120CT98 E E 1 1 10 10 Spiochaetopterus costarum Cossura delta 1 1 120CT98 E 1 10 Mediomastus ambiseta 7 120CT98 E 1 10 Aricidea bryani 1 120CT98 E 2 3 Polydora caulleryi 1 120CT98 E 2 3 Streblospio benedicti 18 120CT98 E 2 3 Paraprionospio pinnata 1 120CT98 E 2 3 Mediomastus ambiseta 4 120CT98 E 2 10 Paraprionospio pinnata 2 120CT98 E 2 10 Cossura delta 3 120CT98 E 2 10 Mediomastus ambiseta 2 120CT98 E 2 10 Aricidea bryani 1 120CT98 E 3 3 Rhynchocoela (unidentified) 1 120CT98 E 3 3 Gyptis vittata 1 120CT98 E 3 3 Polydora caulleryi 7 120CT98 E 3 3 Streblospio benedicti 6 120CT98 E 3 3 Paraprionospio pinnata 1 120CT98 E 3 3 Scolclcpis texana 1 120CT98 E 3 3 Mulinia lateralis 2 120CT98 E 3 3 Mediomastusambiseta 3 120CT98 E 3 3 Aricidea bryani 1 120CT98 E 3 10 Sigambra tentaculata 1 120CT98 E 3 10 Gyptis vittata 2 120CT98 E 3 10 Polydora caulleryi 14 120CT98 E 3 10 Paraprionospio pinnata 1 120CT98 E 3 10 Cossura delta 1 120CT98 E 3 10 Mediomastusambiseta 14 120CT98 E 3 10 Aricidea bryani 1 120CT98 F 1 3 Glycinde solitaria 1 120CT98 F 1 3 Streblospio benedicti 3 24 120CT98 F I 3 Paraprionospio pinnala I 120CT98 F I 3 Turbcllaria(unidentified) 1 120CT98 F I 3 Mediomastusambiseta 4 120CT98 F 1 10 Sigambra bassi 1 120CT98 F 1 10 Mediomastusambiseta 3 120CT98 F 2 3 Strcblospio bcncdicli 1 120CT98 F 2 3 Mediomastusambiseta 1 120CT98 F 2 10 Mediomastusambiseta 2 120CT98 F 3 3 Strcblospio bcncdicti 4 120CT98 F 3 3 Mediomastusambiseta 9 120CT98 F 3 10 Mediomastusambiseta 3 05JAN99 A 1 3 Rhynchococla (unidentified) I 05JAN99 A I 3 Strcblospio benedicti 3 05JAN99 A 1 3 Mediomastus ambiseta 16 05JAN99 A 1 10 No species observed 0 05JAN99 A 2 3 Strcblospio benedicti 2 05JAN99 A 2 3 Hobsonia florida 1 05JAN99 A 2 3 Mediomastusambiseta 11 05JAN99 A 2 10 No species observed 0 05JAN99 A 3 3 Strcblospio benedicti 6 05JAN99 A 3 3 Mediomastus ambiseta 10 05JAN99 A 3 10 Mediomastusambiseta 2 05JAN99 B 1 3 Rhynchocoela (unidentified) 1 05JAN99 B 1 3 Polinices duplicatus I 05JAN99 B 13 Parandaliaocularis 1 05JAN99 B 13 Mediomastus ambiseta 2 05JAN99 B 1 10 No species observed 0 05JAN99 B 2 3 Strcblospio benedicti 1 05JAN99 B 2 3 Parandaliaocularis I 05JAN99 B 2 3 Mediomastus ambiseta 8 05JAN99 B 2 10 Rhynchocoela (unidentified) 1 05JAN99 B 3 3 Rhynchocoela (unidentified) 1 05JAN99 B 3 3 Mediomastus ambiseta 4 05JAN99 B 3 10 No species observed 0 05JAN99 C 1 3 Lumbrinerisparvapedata I 05JAN99 C 1 3 Strcblospio benedicti 1 05JAN99 C 1 3 Spiochaetoptems costarum 1 05JAN99 C 1 3 Aligena texasiana 1 05JAN99 C 1 3 Mulinia lateralis 1 05JAN99 C 1 3 Parandaliaocularis 1 05JAN99 C 1 3 Mediomastusambiseta 10 05JAN99 C 1 10 Rhynchocoela (unidentified) 2 05JAN99 C 1 10 Sigambra tenlaculata 2 05JAN99 C 1 10 Paraonidcs lyra 1 05JAN99 C 1 10 Parandaliaocularis 1 05JAN99 C 1 10 Mediomastus ambiseta 6 05JAN99 C 2 3 Strcblospio bcncdicli 8 05JAN99 C 2 3 Mulinia lateralis 2 05JAN99 05JAN99 C C 2 2 3 3 Eulimostoma sp Mediomastus ambiseta 1 2 05JAN99 C 2 3 Euclymcnc sp. B 1 25 05JAN99 C 2 10 Sigambra bassi 1 05JAN99 C 2 10 Cossura delta 3 05JAN99 C 2 10 Mediomastusambiseta 6 05JAN99 C 2 10 Euclymcne sp. B 1 05JAN99 C 3 3 Rhynchocoela (unidentified) 1 05JAN99 C 3 3 Rhynchocoela (unidentified) 1 05JAN99 C 3 3 Mediomastusambiseta 3 05JAN99 C 3 10 Rhynchocoela (unidentified) 1 05JAN99 C 3 10 Paraprionospio pinnata 1 05JAN99 C 3 10 Cossura delta 3 05JAN99 C 3 10 Mediomastus ambiseta 8 05JAN99 D I 3 Oligochaetes (unidentified) 6 05JAN99 D 1 3 Gyptis vittata 1 05JAN99 D I 3 Streblospio bcncdicti 3 05JAN99 D 1 3 Periploma margaritaceum 2 05JAN99 D 1 3 Phoronis architecta 1 05JAN99 D 1 10 Rhynchocoela (unidentified) 3 05JAN99 D 1 10 Oligochaetes (unidentified) 5 05JAN99 D 1 10 Cossura delta 2 05JAN99 D I 10 Periploma margaritaceum 2 05JAN99 D 1 10 Ophiuroidea (unidentified) 1 05JAN99 D 1 10 Apseudes sp. A 2 05JAN99 D 1 10 Naineris sp. A 2 05JAN99 D 1 10 Mediomastus ambiseta 1 05JAN99 D 2 3 Oligochaetes (unidentified) 3 05JAN99 D 2 3 Sigambra tentaculata 1 05JAN99 D 2 3 Glycera americana 1 05JAN99 D 2 3 Glycinde solitaria 1 05JAN99 D 2 3 Streblospio benedicti 7 05JAN99 D 2 3 Paraprionospio pinnata 1 05JAN99 D 2 3 Cossura delta 1 05JAN99 D 2 3 Aligena texasiana 2 05JAN99 D 2 3 Periploma margaritaceum 2 05JAN99 D 2 3 Apseudes sp. A 2 05JAN99 D 2 10 Rhynchocoela (unidentified) 1 05JAN99 D 2 10 Oligochaetes (unidentified) 9 05JAN99 D 2 10 Sigambra tentaculata 2 05JAN99 D 2 10 Gyptis vittata 1 05JAN99 D 2 10 Minuspio cirrifera 1 05JAN99 D 2 10 Corbula contracta I 05JAN99 D 2 10 Periploma margaritaceum 22 05JAN99 D 2 10 Ophiuroidea (unidentified) 1 05JAN99 D 2 10 Apseudes sp. A 4 05JAN99 D 2 10 Naineris sp. A 2 05JAN99 D 2 10 Mediomastus ambiseta I 05JAN99 D 2 10 Malmgrcniclla taylori 1 05JAN99 D 3 3 Glycinde solitaria 1 05JAN99 D 3 3 Streblospio bcncdicti 5 05JAN99 D 3 3 Periploma margaritaceum 1 05JAN99 D 3 3 Mediomastusambiseta 2 05JAN99 D 3 10 Streblospio bcncdicti 3 26 05JAN99 D 3 10 Minuspio cirrifcra 2 05JAN99 D 3 10 Pcriploma margaritaccum 4 05JAN99 D 3 10 Ophiuroidca (unidentified) I 05JAN99 D 3 10 Naincris A sp. 1 05JAN99 D 3 10 Mediomastusambiseta 3 05JAN99 E I 3 Sigambra tentaculata 1 05JAN99 E I 3 Gyptis viltata 3 05JAN99 E 1 3 Polydora caulleryi I 05JAN99 E 1 3 Strcblospio bcncdicti 3 05JAN99 E 1 3 Cossura delta 2 05JAN99 E 1 3 Mediomastus ambiseta 1 05JAN99 EllO Paraprionospio pinnata 2 05JAN99 E I 10 Apoprionospio pygmaea 2 05JAN99 E 10 I Cossura delta 2 05JAN99 E I 10 Mediomastus ambiseta 1 05JAN99 E 2 3 Rhynchocoela (unidentified) 1 05JAN99 E 2 3 Glycinde solilaria 1 05JAN99 E 2 3 Polydora caulleryi 3 05JAN99 E 2 3 Strcblospio bcnedicti 1 05JAN99 E 2 3 Cossura delta 1 05JAN99 E 2 3 Ampelisca abdita 1 05JAN99 E 2 10 Apoprionospio pygmaea 1 05JAN99 E 2 10 Spiochaetoptcrus coslarum 1 05JAN99 E 2 10 Cossura delta 4 05JAN99 E 2 10 Mediomastusambiseta 2 05JAN99 E 3 3 Rhynchocoela (unidentified) 1 05JAN99 E 3 3 Ancistrosyilis jonesi 1 05JAN99 E 3 3 Gyptis vittata 1 05JAN99 E 33 Glycinde solilaria 1 05JAN99 E33 Polydora caulleryi 14 05JAN99 E 3 3 Strcblospio bcnedicti 3 05JAN99 E3 10 Rhynchocoela (unidentified) I 05JAN99 E 3 10 Gyptis vittata 2 05JAN99 E3 10 Polydora caulleryi 7 05JAN99 E 3 10 Paraprionospio pinnata I 05JAN99 E 3 10 Apoprionospio pygmaea 1 05JAN99 E 3 10 Spiochaetoptcrus costarum 1 05JAN99 E 10 3 Mediomastusambiseta 1 05JAN99 F 1 3 Polydora sp. 1 05JAN99 F 1 3 Strcblospio bcnedicti 6 05JAN99 F I 3 Mediomastusambiseta 32 05JAN99 F 1 10 Mediomastus ambiseta 9 05JAN99 F 2 3 Strcblospio bcnedicti 1 05JAN99 F 2 3 Mediomastus ambiseta 27 05JAN99 F 2 10 Mediomastusambiseta I 05JAN99 F 3 3 Strcblospio bcncdicti 7 05JAN99 F3 3 Oslracoda (unidentified) 1 05JAN99 F 3 3 Macoma milchclli 1 05JAN99 F 3 3 Mediomastusambiseta 22 05JAN99 F 3 10 Mediomastus ambiseta 3 27 06APR99 A 1 3 Rhynchococla (unidentified) 2 06APR99 A 1 3 Strcblospio bcncdicti 2 06APR99 A 1 3 Capitella capitata 1 06APR99 A 1 3 Ampelisca abdita 1 06APR99 A 1 3 Mcdiomastus ambiseta 2 06APR99 A 1 10 Mcdiomastus ambiseta 1 06APR99 A 2 3 Rhynchococla (unidentified) 3 06APR99 A 2 3 Strcblospio benedicti 5 06APR99 A 2 3 Mediomastusambiseta 12 06APR99 A 2 10 Rhynchococla (unidentified) 1 06APR99 A 2 10 Parandaliaocularis 3 06APR99 A 2 10 Mediomastus ambiseta 5 06APR99 A 3 3 Rhynchococla (unidentified) 1 06APR99 A 3 3 Strcblospio benedicti 6 06APR99 A 3 3 Littoridinasphinctostoma 1 06APR99 A 3 3 Mediomastus ambiseta 5 06APR99 B I 3 Rhynchococla (unidentified) 1 06APR99 B I 3 Glycinde solitaria 1 06APR99 B I 3 Mediomastus ambiseta 5 06APR99 B I 10 Mediomastusambiseta 1 06APR99 B 2 3 Streblospio benedicti 1 06APR99 B 2 3 Mulinia lateralis 1 06APR99 B 2 3 Ostracoda (unidentified) 1 06APR99 B 2 3 Mediomastus ambiseta 8 06APR99 B 2 10 Rhynchococla (unidentified) 1 06APR99 B 2 10 Mediomastusambiseta 7 06APR99 B 3 3 Streblospio benedicti 4 06APR99 B 3 3 Ostracoda (unidentified) I 06APR99 B 3 3 Mediomastusambiseta 7 06APR99 B 3 10 Glycinde solitaria 1 06APR99 B 3 10 Cossura delta 1 06APR99 B 3 10 Mediomastus ambiseta 2 06APR99 C 1 3 Mediomastus ambiseta 1 06APR99 C 1 10 Mediomastus ambiseta 1 06APR99 C 2 3 Mediomastusambiseta 1 06APR99 C 2 10 Glycinde solitaria 1 06APR99 C 2 10 Paraprionospio pinnata 1 06APR99 C 2 10 Pilargiidae (unidentified) I 06APR99 C 2 10 Mediomastus ambiseta 3 06APR99 C 3 3 Cyclaspis varians 1 06APR99 C 3 3 Mediomastus ambiseta 1 06APR99 C 3 10 Cossura delta 1 06APR99 C 3 10 Mediomastus ambiseta 2 06APR99 D 1 3 Ancistrosyllis joncsi 1 06APR99 D 1 3 Cossura della 1 06APR99 D 1 3 Nuculana acuta 1 06APR99 D 1 3 Abra acqualis I 06APR99 D 1 3 Corbula contracta 1 06APR99 D 1 3 Apscudcs sp. A 2 06APR99 D 1 3 Mcdiomastus ambiseta 1 06APR99 D 1 10 Rhynchococla (unidentified) 1 28 06APR99 D I 10 Oligochactcs (unidentified) 4 06APR99 D I 10 Ancistrosyllis jonesi 1 06APR99 D 1 10 Gyptis vittata I 06APR99 D 1 10 Diopatra cuprca I 06APR99 D 1 10 Minuspio cirrifera 4 00APR99 D 1 10 Paraonidcs lyra I 06APR99 D I 10 Lepton sp. 4 06APR99 D I 10 Abra acqualis I 06APR99 D 1 10 Corbula contracta 1 06APR99 D I 10 Ophiuroidca (unidentified) 1 06APR99 D 1 10 Apscudcs sp. A 2 06APR99 D 1 10 Naineris sp. A 1 06APR99 D 1 10 Mediomastusambiseta 2 06APR99 D 2 3 Rhynchococla (unidentified) 1 06APR99 D 2 3 Gyptis vittata 1 06APR99 D 2 3 Glycinde solitaria 1 06APR99 D 2 3 Paraprionospio pinnata 2 06APR99 D 2 3 Corbula contracta 1 06APR99 D 2 3 Schizocardium sp. 1 06APR99 D 2 3 Armandiamaculata 1 06APR99 D 2 3 Apseudes sp. A 49 06APR99 D 2 3 Mediomastusambiseta 2 06APR99 D 2 10 Rhynchococla (unidentified) 2 06APR99 D 2 10 Oligochaetes (unidentified) 5 06APR99 D 2 10 Sigambra tentaculata 2 06APR99 D 2 10 Polydora caullcryi 3 06APR99 D 2 10 Cossura delta 2 06APR99 D 2 10 Lepton sp. 4 06APR99 D 2 10 Abra acqualis 1 06APR99 D 2 10 Corbula contracta 1 06APR99 D 2 10 Phoronis architecta 1 06APR99 D 2 10 Ophiuroidca (unidentified) 2 06APR99 D 2 10 Apseudes sp. A 32 06APR99 D 2 10 Mediomastusambiseta 4 06APR99 D 3 3 Anthozoa(unidentified) 1 06APR99 D 3 3 Polydora caulleryi 1 06APR99 D 3 3 Paraprionospio pinnata 1 06APR99 D 3 3 Thary.x setigera 1 06APR99 D 3 3 Corbula contracta 3 06APR99 D 3 3 Schizocardium sp. 3 06APR99 D\ 3 3 Ophiuroidca (unidentified) 1 06APR99 D 3 3 Apscudcs sp. A 24 06APR99 D 3 3 Mediomastus ambiseta 2 06APR99 D 3 3 Eudorclla sp. 1 06APR99 D 3 10 Rhynchococla (unidentified) 1 06APR99 D 3 10 Glycinde solitaria 1 06APR99 D 3 10 Lepton sp. 6 06APR99 D 3 10 Corbula contracta 1 06APR99 D 3 10 Ophiuroidca (unidentified) 1 06APR99 D 3 10 Apscudcs sp. A 26 06APR99 D 3 10 Mediomastus ambiseta 1 29 06APR99 E I 3 Gyptis vittata 1 06APR99 E I 3 Spiochactoptcms costamm 1 06APR99 E 1 3 Mclinna maculata 1 06APR99 E 1 3 Schizocardium sp. 3 06APR99 E 1 3 Mcdiomastus ambiscta 2 06APR99 E 1 10 Haploscoloplos fragilis 1 06APR99 E 1 10 Cossura delta 4 06APR99 E I 10 Mcdiomastus ambiseta 2 06APR99 E 1 10 Aricidea bryani 1 06APR99 E 2 3 Spiochactoptcms costamm 1 06APR99 E 2 3 Haploscoloplos fragilis I 06APR99 E 2 3 Ogyridcs limicola 1 06APR99 E 2 3 Schizocardium sp. 3 06APR99 E 2 3 Nereidae (unidentified) I 06APR99 E 2 3 Turbellaria (unidentified) 1 06APR99 E 2 3 Apseudes sp. A 1 06APR99 E 2 3 Mcdiomastusambiseta 2 06APR99 E 2 10 Gyptis vittata 1 06APR99 E 2 10 Paraprionospio pinnata 2 06APR99 E 2 10 Haploscoloplos fragilis 1 06APR99 E 2 10 Cossura delta 3 06APR99 E 2 10 Schizocardium sp. 1 06APR99 E 2 10 Ophiuroidea (unidentified) I 06APR99 E 2 10 Mcdiomastus ambiseta 3 06APR99 E 2 10 Malmgreniella taylori 1 06APR99 E 2 10 Aricidea bryani 1 06APR99 E 3 3 Rhynchocoela (unidentified) 1 06APR99 E 3 3 Oligochaetes (unidentified) 1 06APR99 E 3 3 Spiochaetoptems costamm 1 06APR99 E 3 3 Haploscoloplos fragilis 1 06APR99 E 3 3 Cossura delta 1 06APR99 E 3 3 Phoronis architecta 1 06APR99 E 3 3 Schizocardium sp. 6 06APR99 E 3 3 Eulimostoma sp. 1 06APR99 E 3 3 Mcdiomastus ambiseta 3 06APR99 E 3 10 Glycinde solitaria 1 06APR99 E 3 10 Polydora caulleryi 1 06APR99 E 3 10 Paraprionospio pinnata 1 06APR99 E 3 10 Cossura delta 3 06APR99 E 3 10 Schizocardium sp. 1 06APR99 E 3 10 Nuculana concenlrica 1 06APR99 E 3 10 Turbellaria(unidentified) 1 06APR99 E 3 10 Caecum johnsoni 1 06APR99 E 3 10 Mcdiomastus ambiseta 2 06APR99 E 3 10 Aricidea bryani 1 06APR99 F 1 3 Slrcblospio bcncdicti 2 06APR99 F 1 3 Ampclisca abdita 7 06APR99 F 1 3 Mcdiomastus ambiseta 30 06APR99 F 1 10 Cossura delta 1 06APR99 F 1 10 Caecum johnsoni 1 06APR99 F 1 10 Mcdiomastus ambiseta 4 30 06APR99 F 2 3 Slrcblospio bcnedicti 6 06APR99 F 2 3 Haploscoloplos fragilis I 06APR99 F 2 3 Ostracoda (unidentified) 2 06APR99 F 2 3 Ampelisca abdita 8 06APR99 F 2 3 Mcdiomastus ambiseta 22 06APR99 F 2 10 Mcdiomastus ambiseta 25 06APR99 F 3 3 Rhynchococla (unidentified) 1 06APR99 F 3 3 Slrcblospio bcnedicti 7 06APR99 F 3 3 Ostracoda (unidentified) 1 06APR99 F 3 3 Ampelisca abdita 1 06APR99 F 3 3 Eulimosloma sp. 1 06APR99 F 3 3 Mcdiomastusambiseta 18 06APR99 F 3 10 Rhynchococla (unidentified) 1 06APR99 F 3 10 Mcdiomastus ambiseta 22 Guadalupe Estuary Date Station Replicate Section Species n 07JUL98 A 1 3 Slrcblospio bcnedicti 10 07JUL98 A 1 3 Mulinialateralis 3 07JUL98 A 1 3 Rangia cuneata 5 07JUL98 A 1 3 Callianassa sp. 1 07JUL98 A 1.3 Littoridinasphinctostoma 38 07JUL98 A 1 10 Littoridinasphinctostoma 1 07JUL98 A 1 10 Parandalia ocularis 2 07JTJL98 A 1 10 Mcdiomastusambiseta 1 07JUL98 A 2 3 Polydora sp. 1 07JUL98 A 2 3 Slrcblospio bcnedicti 4 07JUL98 A 2 3 Mulinialateralis 7 07JUL98 A 2 3 Monoculodes sp. 1 07JUL98 A 2 3 Chironomid larvae 1 07JUL98 A 2 3 Mysidopsis almyra 1 07JUL98 A 2 3 Rangia cuneata 10 07JUL98 A 2 3 Littoridinasphinctostoma 44 07JUL98 A 2 10 Slrcblospio bcnedicti 1 07JUL98 A 3 3 Slrcblospio bcnedicti 6 07JUL98 A 3 3 Mulinia lateralis 9 07JUL98 A 3 3 Monoculodes sp. 1 07JUL98 A> 3 3 Rangia cuneata 4 07JUL98 A 3 3 Callianassa sp. 2 07JUL98 A 3 3 Littoridinasphinctostoma 14 07JUL98 A 3 10 Littoridina sphinctostoma 1 07JUL98 B 1 3 Rhynchococla (unidentified) 1 07JUL98 B 1 3 Slrcblospio bcnedicti 4 07JUL98 B I 3 Mysidopsis almyra 1 07JUL98 B 1 3 Littoridina sphinctostoma 9 07JUL98 B 1 3 Mcdiomastus ambiseta 25 07JUL98 B 1 10 No species observed 0 07JUL98 B 2 3 Slrcblospio bcnedicti 2 31 07JUL98 B 2 3 Littoridinaspliinctostoma 6 07JUL98 B 2 3 Mcdiomastus ambiscla 15 07JUL98 B 2 10 Mcdiomastus ambiscta 2 07JUL98 B 3 3 Strcblospio bcnedicli 10 07JUL98 B 3 3 Littoridinaspliinctostoma 17 07JUL98 B 3 3 Mcdiomastus ambiscta 5 07JUL98 B 3 10 Mcdiomastus ambiscta 20 07JUL98 C I 3 Strcblospio bcncdicti 2 07JUL98 C 1 3 Maldanidae(unidentified) 1 07JUL98 C I 3 Mulinia lateralis 1 07JUL98 C 1 3 Cyclaspis varians 1 07JUL98 C 1 3 Littoridinaspliinctostoma 2 07JUL98 C 1 3 Mcdiomastus ambiscta 23 07JUL98 C 1 10 Caecum johnsoni 1 07JUL98 C 1 10 Mcdiomastusambiscta II 07JUL98 C 2 3 Strcblospio benedicti 2 07JUL98 C 2 3 Mulinia lateralis 1 07JUL98 C 2 3 Littoridinaspliinctostoma 3 07JUL98 C 2 3 Mcdiomastus ambiseta 16 07JUL98 C 2 10 Mcdiomastusambiseta 3 07JUL98 C 3 3 Glycinde solitaria 1 07JUL98 C 3 3 Strcblospio bcnedicli 4 07JUL98 C 3 3 Haploscoloplos fragilis 1 07JUL98 C 3 3 Cyclaspis varians 2 07JUL98 C 3 3 Littoridinaspliinctostoma 5 07JUL98 C 3 3 Mcdiomastusambiseta 34 07JUL98 C 3 10 Mcdiomastus ambiseta 11 07JUL98 D 1 3 Mulinia lateralis 1 07JUL98 D 1 3 Monoculodcs sp. 1 07JUL98 D 1 3 Parandaliaocularis 1 07JUL98 D 1 3 Mcdiomastus ambiseta 13 07JUL98 D I 10 Glycinde solitaria 1 07JUL98 D 1 10 Parandaliaocularis 1 07JUL98 D 1 10 Mcdiomastusambiseta 3 07JUL98 D 2 3 Strcblospio benedicti 2 07JUL98 D 2 3 Cyclaspis varians I 07JUL98 D 2 3 Nereidae(unidentified) 1 07JUL98 D 2 3 Parandaliaocularis 1 07JUL98 D 2 3 Mcdiomastus ambiscta 14 07JUL98 D 2 10 Parandalia ocularis 4 07JUL98 D 2 10 Mcdiomastus ambiscta 1 07JUL98 D 3 3 Strcblospio bcnedicli 1 07JUL98 D 3 3 Parandaliaocularis 1 07JUL98 D 3 3 Mcdiomastus ambiscta 11 07JUL98 D 3 10 Rhynchococla (unidentified) 1 07JUL98 D 3 10 Haploscoloplos fragilis 1 07JUL98 D 3 10 Parandaliaocularis 1 07JUL98 D 3 10 Mcdiomastus ambiscta 3 130CT98 A 1 3 Strcblospio bcnedicli 7 130CT98 A 1 3 Rangia cuncala 1 130CT98 A I 3 Callianassa sp. 1 32 130CT98 A I 3 Littoridinasphinctostoma 7 130CT98 A I 10 Parandaliaocularis 2 130CT98 A 2 3 Rhynchococla (unidentified) I 130CT98 A 2 3 Strcblospio benedicti 10 130CT98 A 2 3 Rangia cuncata 1 130CT98 A 2 3 Littoridinasphinctostoma 5 130CT98 A 2 3 Mediomastusambiseta 6 130CT98 ‘A 2 10 Rhynchococla (unidentified) 1 130CT98 A 2 10 Parandaliaocularis I 130CT98 A 2 10 Mediomastusambiseta 2 130CT98 A 3 3 Rhynchococla (unidentified) 1 130CT98 A 3 3 Strcblospio bcnedicti 10 130CT98 A 3 3 Littoridinasphinctostoma 7 130CT98 A 3 3 Mediomastusambiseta 7 L3OCT9B A 3 10 No species observed 0 130CT98 B 1 3 Strcblospio benedicti 8 130CT98 B 1 3 Mediomastusambiseta 11 130CT98 B 1 10 Mediomastusambiseta 13 130CT98 B 2 3 Strcblospio bcnedicti 17 130CT98 B 2 3 Littoridinasphinctostoma 5 130CT98 B 2 3 Mediomastusambiseta 8 130CT98 B 2 10 Mediomastusambiseta 5 130CT98 B 3 3 Strcblospio bcnedicti 9 130CT98 B 3 3 Mulinia lateralis 1 130CT98 B 3,3 Littoridina sphinctostoma 2 130CT98 B 3 3 Mediomastusambiseta 3 130CT98 B 3 10 Mediomastusambiseta 12 130CT98 C 1 3. Leucon sp. 1 130CT98 C 1 3 Macoma mitchelli 1 130CT98 C 1 3 Rictaxis punctostriatus 1 130CT98 C 1 3 Mediomastusambiseta 20 130CT98 C 1 10 Rhynchococla (unidentified) 1 130CT98 C 1 10 Paraprionospio pinnnta 1 130CT98 C 1 10 Haploscoloplos fragilis 1 130CT98 C 1 10 Mediomastusambiseta 7 130CT98 C 2 3 Gyptis vittata 1 130CT98 C 2 3 Mediomastusambiseta 22 130CT98 C 2 10 Parandaliaocularis 2 130CT98 C 2 10 Mediomastusambiseta 16 130CT98 C 3 3 Glycinde solitaria 1 130CT98 C 3 3 Strcblospio bcnedicti 2 1300T98 C 3 3 Eulimostoma sp. 1 130CT98 C 3 3 Mediomastusambiseta 25 130CT98 C 3 10 Rhynchococla (unidentified) I 130CT98 C 3 10 Mediomastus ambiseta 4 130CT98 D 1 3 Strcblospio bcnedicti 1 130CT98 D 1 3 Capitclla capitata 1 l ’OCT9B D 1 3 Hcmicyclops sp. 1 ! •>OCT9B D 1 3 Mediomastus ambiseta 6 I 30CT98 D 1 10 Hcmicyclops sp. 3 130CT98 D 2 3 Strcblospio bcnedicti 1 33 130CT98 D 2 3 Mulinialateralis 1 130CT98 D 2 3 Mcdiomastus ambiscta 6 130CT98 D 2 10 Paraprionospio pinnata 1 130CT98 D 2 10 Mcdiomastusambiscta I 130CT98 D 3 3 Rhynchococla (unidentified) 1 130CT98 D 3 3 Streblospio bcncdicli 3 130CT98 D 3 3 Cyclaspis varians 1 130CT98 D 3 3 Nudibranchia(unidentified) 1 130CT98 D 3 3 Parandaliaocularis 1 130CT98 D 3 3 Mcdiomastusambiscta 9 130CT98 D 3 10 Spiochaetopterus costarum 2 130CT98 D 3 10 Hemicyclops sp. 2 130CT98 D 3 10 Mcdiomastusambiscta 2 130CT98 E 1 3 Rhynchococla (unidentified) I 130CT98 E 1 3 Glycinde solitaria 1 130CT98 E 1 3 Streblospio benedicti 2 130CT98 E 1 3 Paraprionospio pinnata 2 130CT98 E 1 3 Spiochaetopterus costarum 4 130CT98 E 1 3 Mcdiomastusambiseta 3 130CT98 E 1 10 Rhynchococla (unidentified) 1 130CT98 E 1 10 Glycinde solitaria 1 130CT98 E 1 10 Spiochaetopterus costarum 2 130CT98 E 1 10 Parandaliaocularis 1 130CT98 E 2 3 Rhynchococla (unidentified) 1 130CT98 E 2 3 Glycinde solitaria 1 130CT98 E 2 3 Paraprionospio pinnata 1 130CT98 E 2 3 Spiochaetopterus costarum 3 130CT98 E 2 3 Mcdiomastusambiseta 5 130CT98 E 2 10 Spiochaetopterus costarum 4 130CT98 E 2 10 Mediomastusambiseta I 130CT98 E 3 3 Streblospio benedicti 1 130CT98 E 3 3 Paraprionospio pinnata 1 130CT98 E 3 3 Spiochaetopterus costarum 1 130CT98 E 3 10 Spiochaetopterus costarum 2 130CT98 E 3 10 Cossura delta 1 130CT98 F 1 3 Streblospio benedicti 6 130CT98 F 1 3 Periploma margaritaceum 1 130CT98 F 1 3 Grandidierellabonnicroidcs 1 130CT98 F 1 3 Mcdiomastusambiscta 20 130CT98 F 1 10 Rhynchococla (unidentified) 1 130CT98 F 1 10 Cossura delta 1 130CT98 F 1 10 Aligena texasiana 2 130CT98 F I 10 Ophiuroidca (unidentified) 1 130CT98 F 1 10 Mcdiomastus ambiscta 7 130CT98 F 1 10 Euclymene sp. B 3 130CT98 F 1 10 Malmgrcniclla taylori 1 130CT98 F 2 3 Streblospio benedicti 2 130CT98 F 2 10 Gyptis viltata I 130CT98 F 2 10 Cossura delta 1 130CT98 F 2 10 Mcdiomastus ambiscta 7 130CT98 F 2 10 Euclymene sp. B 3 34 130CT98 F 3 3 Strcblospio bcncdicti 3 130CT98 F 3 3 Mcdiomastusambiscta 7 130CT98 F 3 10 Paraprionospio pinnata I 130CT98 F 3 10 Mcdiomastusambiscta 6 130CT98 F 3 10 Euclymcnc sp. B 2 06JAN99 A 1 3 Mulinia lateralis 1 06JAN99 A 1 3 Chironomid larvae 1 06JAN99 A 1 3 Rangia cimeata 1 06JAN99 A I 3 Littoridinasphinctostoma 13 06JAN99 A 1 3 Mcdiomastusambiscta 2 06JAN99 A 1 10 Mcdiomastusambiscta 1 06JAN99 A 2 3 Littoridina sphinctostoma 16 06JAN99 A 2 3 Mcdiomastusambiscta 2 06JAN99 A 2 10 No species observed 0 06JAN99 A 3 3 Littoridina sphinctostoma 25 06JAN99 A 3 10 Rhynchocoela (unidentified) 1 06JAN99 A 3 10 Mcdiomastusambiscta 1 06JAN99 B 1 3 Littoridina sphinctostoma 16 06JAN99 B I 10 Rhynchocoela (unidentified) 1 06JAN99 B 1 10 Mcdiomastusambiscta 1 06JAN99 B 2 3 Rhynchocoela (unidentified) 2 06JAN99 B 2 3 Littoridina sphinctostoma 6 06JAN99 B 2 3 Mcdiomastusambiscta 1 06JAN99 B 2 10 Rhynchocoela (unidentified) 2 06JAN99 B 2 10 Oligochaetes (unidentified) 1 06JAN99 B 2 10 Mcdiomastusambiscta 3 06JAN99 B 3 3 Littoridina sphinctostoma 10 06JAN99 B 3 3 Mediomastusambiscta 8 06JAN99 B 3 10 Rhynchocoela (unidentified) 1 06JAN99 B 3 10 Capitella capitala 2 06JAN99 C 1 3 Mediomastusambiscta 5 06JAN99 C 1 10 No species observed 0 06JAN99 C 2 3 Mediomastusambiscta 13 06JAN99 C 2 10 Mediomastusambiscta 2 06JAN99 C 3 3 Mcdiomastusambiscta 7 06JAN99 C 3 10 Mcdiomastusambiscta 1 06JAN99 D 1 3 Strcblospio bcncdicti 1 06JAN99 D I 3 Mcdiomastusambiscta 10 06JAN99 D 1 10 No species observed 0 06JAN99 D 2 3 Strcblospio bcncdicti I 06JAN99 D\ 2 3 Mcdiomastusambiscta 16 06JAN99 D 2 10 No species observed 0 06JAN99 D 3 3 Rhynchocoela (unidentified) 1 06JAN99 D 3 3 Strcblospio bcncdicti 1 06JAN99 D 3 3 Parandaliaocularis I 06JAN99 D 3 3 Mcdiomastusambiscta 6 06JAN99 D 3 10 No species observed 0 07APR99 A 1 3 Chironomid larvae 1 07APR99 A 1 3 Mysidopsis almyra 1 07APR99 A 1 3 Rangia cuncata 7 07APR99 A I 3 Callianassa sp. 1 35 07APR99 A I 3 Littoridinasphinctostoma 10 07APR99 A 1 3 Parandaliaocularis 1 07APR99 A 1 3 Mcdiomastus ambiseta 2 07APR99 A 1 10 Chironoinid larvae 1 07APR99 A 1 10 Littoridinasphinctostoma 4 07APR99 A 1 10 Mcdiomastus ambisela I 07APR99 A 2 3 Mulinia lateralis 2 07APR99 A 2 3 Chironoinidlarvae I 07APR99 A 2 3 Rangia cuneata 10 07APR99 A 2 3 Littoridinasphinctostoma 3 07APR99 A 2 3 Mcdiomastus ambiseta 7 07APR99 A 2 10 No species observed 0 07APR99 A 3 3 Mulinia lateralis 1 07APR99 A 3 3 Mysidopsis almyra 1 07APR99 A 3 3 Rangia cuneata 5 07APR99 A 3 3 Littoridinasphinctostoma 9 07APR99 A 3 3 Mcdiomastus ambiseta 1 07APR99 A 3 10 Chironoinid larvae 1 07APR99 A 3 10 Littoridina sphinctostoma I 07APR99 A 3 10 Mcdiomastus ambiseta 1 07APR99 B I 3 Rhynchocoela (unidentified) 1 07APR99 B 1 3 Mulinia lateralis 2 07APR99 07APR99 B B 1 1 3 3 Littoridina sphinctostoma Mcdiomastus ambiseta 9 6 07APR99 B 1 10 Rhynchocoela (unidentified) 1 07APR99 B 2 3 Mulinia lateralis 1 07APR99 B 2 3 Littoridina sphinctostoma 2 07APR99 B 2 3 Mcdiomastus ambiseta 2 07APR99 B 2 10 Mcdiomastus ambiseta 1 07APR99 07APR99 B B 3 3 3 3 Strcblospio benedicti Mulinia lateralis 2 1 07APR99 B 3 3 Mcdiomastus ambiseta 1 07APR99 B 3 10 Mcdiomastus ambiseta 2 07APR99 C 1 3 Strcblospio benedicti 2 07APR99 C 1 3 Mulinia lateralis 3 07APR99 C 1 3 Mcdiomastus ambiseta 11 07APR99 C I 10 Rhynchocoela (unidentified) 1 07APR99 C 1 10 Mcdiomastus ambiseta 6 07APR99 C 2 3 Rhynchocoela (unidentified) 1 07APR99 C 2 3 Strcblospio benedicti 13 07APR99 C 2 3 Mulinia lateralis 1 07APR99 C 2 3 Mcdiomastus ambiseta 10 07APR99 C 2 10 Rhynchocoela (unidentified) 1 07APR99 C 2 10 Mcdiomastus ambiseta 14 07APR99 C 3 3 Strcblospio benedicti 4 07APR99 C 3 3 Mulinia lateralis 2 07APR99 C 3 3 Mcdiomastus ambiseta 8 07APR99 C 3 10 Capitclla capitata 1 07APR99 C 3 10 Mcdiomastus ambiseta 12 07APR99 D 1 3 Ncanthcs succinca 1 07APR99 D 1 3 Strcblospio benedicti 6 36 07APR99 D I 3 Mcdiomastusambiseta 15 07APR99 D 1 10 Diopatra cuprea I 07APR99 D 2 3 Glycindc solitaria 1 07APR99 D 2 3 Streblospio bcncdicti 5 07APR99 D 2 3 Hemicyclops sp. 17 07APR99 D 2 3 Mcdiomastusambiseta 19 07APR99 D 2 10 Glycindc solitaria 1 07APR99 D 2 10 Capitclla capitata 1 07APR99 D 2 10 Hemicyclops sp. 3 07APR99 D 2 10 Mcdiomastusambiseta 1 07APR99 D 3 3 Streblospio bcncdicti 3 07APR99 D 3 3 Capitclla capitata 1 07APR99 D 3 3 Mcdiomastus ambiseta 16 07APR99 D 3 10 Parandaliaocularis 1 07APR99 D 3 10 Mcdiomastus ambiseta 5 37 Sediment Elemental Composition in Upper Laguna Madre Middleofsectiondepthincm,Nitrogen andCarbonin%dryweightofsediment,porosity%wet weight ofsediment, nitrogen and carbon isotope values. Bay Date Station Replicate Section Porosity %N 5 1SN %C 6 13 C LM 17-May-99 6 1 1 0.8074 0.29 3.85 2.86 -16.38 LM 17-May-99 6 1 3 0.7043 0.27 3.54 2.85 -15.70 LM 17-May-99 6 1 6 0.6503 0.20 5.06 2.20 -15.53 LM 17-May-99 6 1 11 0.6643 0.18 4.98 2.10 -14.71 LM 17-May-99 6 1 16 0.6880 0.22 3.82 3.12 -12.78 LM 17-May-99 6 1 20 0.6789 0.20 3.95 2.91 -12.53 LM 17-May-99 6 1 40 0.6157 0.27 2.88 6.12 -6.84 LM 17-May-99 6 1 60 0.6950 0.21 3.60 3.24 -12.12 LM 17-May-99 6 1 80 0.6476 0.23 3.46 5.11 -7.42 LM 17-May-99 6 1 100 0.6945 0.19 4.04 2.96 -12.07 LM 17-May-99 6 2 1 0.7422 0.31 3.94 3.13 -14*77 LM 17-May-99 6 2 3 0.5989 0.23 3.83 2.67 -13.14 LM 17-May-99 6 2 6 0.6425 0.16 4.75 2.10 -12.21 LM 17-May-99 6 2 11 0.6983 0.20 4.28 2.30 -14.66 LM 17-May-99 6 2 16 0.6866 0.21 3.82 2.81 -12.91 LM 17-May-99 6 2 20 0.7188 0.20 3.99 2.47 -13.42 LM 17-May-99 6 2 40 0.7004 0.33 2.62 5.23 -9.39 LM 17-May-99 6 2 60 0.7002 0.24 3.38 3.32 -12.18 LM 17-May-99 6, 2 80 0.6517 0.20 3.41 6.78 -7.64 LM 17-May-99 6 2 100 0.7035 0.20 4.00 3.09 -11.35 LM 17-May-99 24 1 1 0.7724 0.24 5.91 1.94 -18.48 LM 17-May-99 24 1 3 0.7391 0.20 5.94 2.07 -15.43 LM 17-May-99 24 1 6 0.6792 0.15 6.67 2.02 -12.92 LM 17-May-99 24 1 11 0.7015 0.14 6.56 1.46 -16.22 LM 17-May-99 24 1 16 0.7405 0.13 5.32 1.34 -19.12 LM 17-May-99 24 1 20 0.7300 0.14 5.13 1.39 -17.84 LM 17-May-99 24 1 40 0.7289 0.12 5.34 1.70 -12.87 LM 17-May-99 24 1 60 0.6665 0.23 3.12 4.14 -9.31 LM 17-May-99 \24 1 80 0.6851 0.13 4.43 2.67 -9.16 LM 17-May-99 24 1 100 0.6731 0.16 3.89 3.05 -9.95 LM 17-May-99 24 2 1 0.7533 0.24 5.50 2.04 -17.59 LM 17-May-99 24 2 3 0.7566 0.21 5.57 1.83 -18.79 LM 17-May-99 24 2 6 0.6722 0.16 6.70 2.00 -13.34 LM 17-May-99 24 2 11 0.6958 0.13 6.68 1.41 -16.27 LM 17-May-99 24 2 16 0.7262 0.13 5.76 1.31 -18.65 LM 17-May-99 24 2 20 0.7369 0.14 5.16 1.44 -18.23 LM 17-May-99 24 2 40 0.6685 0.17 4.22 2.48 -12.65 38 LM 17-May-99 24 2 60 0.6959 0.19 4.58 2.90 -11.55 LM 17-May-99 24 2 80 0.6606 0.17 3.56 3.81 -7.43 LM 17-May-99 24 2 100 0.6721 0.17 3.88 2.93 -10.58 LM 26-May-99 135 G 1 1 0.4406 0.09 2.71 1.06 -12.06 LM 26-May-99 135 G 1 3 0.3764 0.14 2.56 1.84 -11.26 LM 26-May-99 135 G 1 6 0.2744 0.08 2.69 1.08 -11.15 LM 26-May-99 135 G 1 11 0.2187 0.02 2.52 0.90 2.25 LM 26-May-99 135 G 1 16 0.2252 0.04 2.84 4.03 0.10 LM 26-May-99 135 G 1 20 0.2511 0.01 2.89 1.17 0.56 LM 26-May-99 135 G 1 40 0.2091 0.00 0.00 0.34 -0.06 LM 26-May-99 135 G 1 60 0.1964 0.00 0.00 0.27 -0.43 LM 26-May-99 135 G 1 80 0.2663 0.02 3.51 1.32 -1.65 LM 26-May-99 135 G 1 100 0.2244 0.02 2.98 0.81 -2.86 LM 26-May-99 135 G 2 1 0.3573 0.07 2.60 1.01 -9.88 LM 26-May-99 135 G 2 3 0.3573 0.10 2.71 1.38 -10.54 LM 26-May-99 135 G 2 6 0.2404 0.04 3.11 0.79 -6.66 LM 26-May-99 135 G 2 11 0.2043 0.01 3.62 0.77 -0.91 LM 26-May-99 135 G 2 16 0.2209 0.02 3.09 3.33 1.89 LM 26-May-99 135 G 2 20 0.2077 0.01 3.00 2.02 1.35 LM 26-May-99 135 G 2 40 0.2044 0.00 3.37 0.38 0.68 LM 26-May-99 135 G 2 60 0.1994 0.00 3.93 0.52 1.39 LM 26-May-99 135 G 2 80 0.1837 0.01 2.70 1.73 2.03 LM 26-May-99 135 G 2 100 0.2983 LM 17-May-99 189 G 1 1 0.6535 0.59 2.64 6.99 -12.81 LM 17-May-99 189 G 1 3 0.4731 0.15 2.61 1.81 -12.46 LM 17-May-99 189 G 1 6 0.4574 0.19 2.99 2.87 -10.29 LM 17-May-99 189 G 1 11 0.4092 0.07 3.46 1.12 -9.67 LM 17-May-99 189 G 1 16 0.4105 0.12 4.20 2.10 -8.64 LM 17-May-99 189 G 1 20 0.2602 0.04 3.97 1.12 -3.79 LM 17-May-99 189 G 1 40 0.2250 0.02 4.82 0.39 -18.00 LM 17-May-99 189 G 1 60 0.2117 0.02 11.84 0.31 -18.36 LM 17-May-99 189 G 1 80 0.1918 0.01 6.82 0.13 -18.17 LM 17-May-99 189 G 1 100 0.1927 0.01 4.91 0.10 -16.30 LM 17-May-99 189 G 2 1 0.7881 0.76 2.77 8.13 -14.75 LM 17-May-99 189 G 2 3 0.5630 0.17 2.45 1.98 -13.53 LM 17-May-99 189 G 2 6 0.3685 0.09 3.27 1.52 -9.01 LM 17-May-99 189 G 2 11 0.2899 0.04 3.93 0.82 -6.90 LM 17-May-99 189 G 2 16 0.3094 0.05 4.21 1.15 -6.41 LM 17-May-99 189 G 2 20 0.2250 0.03 3.66 0.86 -3.05 LM 17-May-99 189 G 2 40 0.2423 0.01 4.77 0.43 -7.86 LM 17-May-99 189 G 2 60 0.2302 0.02 5.11 0.84 -5.52 LM 17-May-99 189 G 2 80 0.2111 0.01 4.79 0.53 -4.49 LM 17-May-99 IB9G 2 100 0.1990 0.01 4.3 Q 0.22 -8.95 39 AverageVerticalDistributionofElementalContent (%>)amongStations Nitrogen and Carbon in % dry weight ofsediment, nitrogen and carbon isotope values 6 13 Station N(%) 815 N C(%) C 135 G 0.0358 2.6753 1.3026 -3.0111 189 G 0.1205 4.3760 1.6710 -10.4480 24 0.1675 5.1960 2.1965 -14.3190 6 0.2270 3.8600 3.3685 -12.3875 40 DISCUSSION Conditions in Current Sampling Year Following an El Nino event in 1997, 1998 was a dry year. Consequently, salinities were very high during summer 1998 (Figs. 2 and 3). Tropical Storm France brushed by the south 12, 1998 bringing rain and lowering salinities from July to - Texas coast during September 10 - October.However,duringOctober17 18,1998between18and31inchesofrainfell.The ensuing flood may have been one ofthe largest in the Guadalupe River. Bill West, general managerofthe Guadalupe-Bianco River Authoritywas quotedin theCorpus Christi Caller Times as saying “it was a flood larger that one we had ever seen in this part ofthe world before.” We hadsampledOctober12-13justpriortotheflood. Priortotheflood,salinitiesinfluencedby Frances were still relatively high in the Guadalupe Estuary ranging from 2 psu at the most river- influenced station (A) to 18 psu at the most Gulf-influenced station (D). In January 1999, three months aftertheflood, salinity wasstillzero atstationA andonly 8 psuatstationD,indicating effects ofthe flood lasted for several months. By April 1999, six months later, salinities were backtopre-floodlevels. EffectsofFranceswerefeltintheLavaca-ColoradoEstuary,butno traceoftheOctoberfloodwasevidentbyJanuary1999. ThelowestsalinitiesintheLavaca- Colorado Estuary were in July 1999, following an unusually wet summer period. There was a complete salinity gradient from fresh (near zero) to sea water strength (near 30) in the Lavaca-Colorado Estuary only during July 1999 (Fig. 2). The rest of the it was year, evidentlydry,andsalinitieswererelativelyhigh. StationF(nearthemouthoftheColorado River)waslikeStationA(nearthemouthoftheLavacaRiver) onlyduringJanuary1999. Salinities at Station F were similar to salinities near Station C (where Lavaca Bay meets Matagorda Bay) in July and October 1998, but didn’t return to those levels until July 1999. Salinities fluctuated throughout the year at all stations, but generally dropped during the study period because the year started out dry and ended wet. Upper SanAntonioBay(StationsAandB)weresimilarfromJuly 1998throughJanuary i999, but different in April and July 1999 (Fig. 3). Salinities were always higher than Lower San Antonio Bay (Stations C and D). Salinities at Station A (near the mouth ofthe Guadalupe River) were high (9 psu) in July 1998, but dropped throughout the year. In contrast, from January through April 1999, salinities rose substantially at all stations. Generally, salinity is higher at station D (which is nearest Matagorda Bay) than C (which is nearest Aransas Bay). But in a dry period the opposite is true because south Texas estuaries can be hypersaline. 41 Lavaca-Colorado Estuary Figure 2. Salinity change at stations in Lavaca-Colorado Estuary during the sampling period. 42 Guadalupe Estuary Figure 3. Salinity change at stations in Guadalupe Estuary during the sampling period. 43 BenthicResponse inCurrentSampling Year over the The biomass (Fig. 4) and abundance (Fig. 5) remained relatively constant year in the Lavaca-Colorado Estuary. The biomass pattern at the most ocean-influenced station (D) in the Lavaca-Colorado Estuary was different from all other stations. This station, near the Pass of the Matagorda Ship Channel, had the highest biomass all year, but abundance was highest only in April 1999. A bloom ofthe polychaete Polydora caulleryi was responsible for very high densities at station E in October 1998. Unlike past years, stations A and F did not exhibit similar responses to inflow the over year. The response to the October flood in 1998 is evident in the biomass (Fig. 6) and abundance (Fig. 7) changes in the Guadalupe Estuary. was The lowest biomass and abundance recorded in January 1999 following the flood. However, as seen in the past, both biomass and abundance bloomed (in April 1999) following the initial response as salinities increased. The overall influence of inflow is demonstrated by the trend in abundance and biomass among the stations. Stations A and B had higher biomass than stations C and D from July 1998 through January1999. ThetrendisespeciallystrongduringthehighsalinityperiodofJuly1998. 44 Lavaca-Colorado Estuary Figure 4. Macrofauna biomass change at stations in Lavaca-Colorado Estuary during the sampling period. 45 Lavaca-Colorado Estuary Figure 5. Macrofauna abundance change at stations in Lavaca-Colorado Estuary during the sampling period. 46 Guadalupe Estuary Figure 6. Macrofauna biomass change at stations in Guadalupe Estuary during the sampling period. 47 Guadalupe Estuary Figure 7. Macrofauna abundance change at stations in Guadalupe Estuary during the sampling period. 48 Long-TermChange inBenthos The Lavaca-Colorado and Guadalupe Estuaries are similar in the amount of freshwater 2 inflow they receive, but different in two key attributes. The Lavaca-Colorado Estuary (910 kmat mean tide) is almost twice as large as the Guadalupe Estuary (579 km2 at mean tide). The Lavaca-Colorado also hasdirectexchangeofmarinewaterwiththeGulfofMexicoviaPass Cavallo and the Matagorda Ship Channel. In contrast, exchange in the Guadalupe Estuary is restricted by Cedar Bayou and is predominantly north-south exchange through the Intracoastal Waterway. The Lavaca-Colorado Estuary has higher estuarine-wide salinities (average 20.4 ± 6.4 psu from 1988-1999; Figs. 8 and 9) than the Guadalupe (average 13.5 ± 8.6 psu from 1987 - 1999; Figs. 10 and 11), which is smaller and has restricted exchange. This indicates freshwater inflow has a greater effect on the upper part of San Antonio Bay than on Lavaca Bay. This conclusion is supported by several pieces of data. At any given time salinities are lower in the Guadalupe than Lavaca-Colorado Estuary. This is true estuarine-wide and at stations A and B (nearest the river inflow source) in both estuaries. The amount oftotal carbon in sediments is much greater in the Guadalupe than in the Lavaca-Colorado (Montagna, 1991). Carbon content ofLavaca-ColoradosedimentsandGuadalupe-stationDsediments about 1%,butcarbon are content in the Guadalupe at station C is 3%, and at stations A and B around 4%. The carbon data indicates thatorganic matterisbeingtrapped ornotexported fromthe Guadalupe Estuary. Profilesofnitrogen contentexhibit the sametrendsfound in carbon, but thereisless difference in total nitrogen content between the estuaries, both being about 0.05% (Montagna, 1991). Sediment texture is similar in both estuaries, and are characterized by silt-clay sediments, with increasing grain sizes from the upper to the lower parts ofthe estuaries. Macrofauna abundance and biomass is generally larger in the Guadalupe Estuary than in the Lavaca-Colorado Estuary. The average biomass in the Lavaca-Colorado from 1988-1999 among all stations was 4.6 ±3.8 g*m'2 (Fig. 8) and average abundance was 11,200 ±6,800 individuals-m' 2 (Fig. 9). The average biomass among all times and stations in the Guadalupe from 1987 1999was6.0±5.0g*m' 2andaverageabundancewas19,600±14,900individuals-m’2(Fig. 10). The differences between the estuaries is probably due to the greater ratio of the volume of inflow relative to size ofthe bays. Diversity is generally greater in the Lavaca-Colorado Estuary (average 16 species found per station-date sampling period) than in the Guadalupe Estuary (average 11 species found per station-date sampling period). These results indicate that freshwater inflow is less diluted by marine water in the Guadalupe Estuary, so we find higher benthicproductivity. ThegreaterGulfexchangeintheLavaca-Coloradoleadstomoreoceanic species present in the that estuary, find higher diversity. - so we The long-term time series of salinity indicates there are large year-to-year fluctuations in both estuaries for freshwater inflow (Fig. 12). We have a continuous cycle of drought and flood conditions. The flood cycles are coincident with El Nino events in the western Pacific Ocean. So, climatic cycles in Texas are apparently caused by global changes. These cycles regulate freshwater inflow, and thus, directly affect the biological communities. The variability in the freshwater inflow cycle results in predictable changes in the estuary. recent El Nino The effects ofevents are obvious in the two estuaries. Salinities declined dramatically with the El Nino events in 1986 1987, 1992 1993, and 1997 -1998. The 1986 and 1992 events had laruer effects in the 49 Guadalupe Estuary, and the 1997 event had a larger effect in the Lavaca-Colorado Estuary. The interveningdryperiodsarealsodifferentinthetwoestuaries. Therehavebeen twomajordry 1994 1997. We periods with high salinities between El Ninos; 1988 1992and are currently in the third dry period, which began in 1998. The main difference between the two estuaries is that thesmallerGuadalupeEstuaryrespondstofloodwithepisodicperiodsoflowsalinity(Fig. 12). Whereas the effects of El Nino are seen in both estuaries, storms have more localized effects. The October 1998 is a good example. The long-term trend from mid-1997 through 1999 was a dry period with increasing salinities (Fig. 12). Flowever, the precipitation that caused the October 1998 flood occurred primarily in the Guadalupe watershed. Therefore, salinities in the Guadalupe Estuary were low through January 1999, whereas salinities in the Lavaca-Colorado Estuary increased. Our study oftheLavaca-Colorado and Guadalupe Estuaries demonstrates the biological effectsofthisElNinodrivencycle. Floodconditionsintroducenutrientrichwatersintothe - estuary which result in lower salinity (Figs. 13 14). This happened in the winter/spring of 1987, 1992 and 1997 in both estuaries. During those El Nino periods the lowest salinities and highest nutrientvalueswererecorded. Duringtheseperiodsthespatialextentofthefreshwaterfaunais increased, and the estuarine fauna replaced the marine fauna in the lower end ofthe estuary. The highlevelofnutrientsstimulated aburstofbenthicproductivity(ofpredominantlyfreshwater and estuarine organisms), which lasts about six months. This was followed by a transition to a drought period with low inflow resulting in higher salinities, lower nutrients, marine fauna, decreased productivity and abundances. At first, the marine fauna responded with a burst of productivity as the remaining nutrients are utilized, but eventually nutrients are depleted resulting in lower macrofauna biomass and densities. This was seen from 1989 to 1990, 1993 to 1995, and from 1997 through the present. Pulsed flood events, particularly in dry years, mitigates these patterns. A longer record is available for station A in Lavaca Bay ofthe Lavaca-Colorado Estuary. Thesedataillustratethatthelong-termtrendis moreobvious, andthatrecordsofeightto ten yearsdurationaremuchmorerevealingthanrecordsofonlythreeyears. Therewasawetperiod in spring of 1985 that was ofthe same magnitude as the spring of 1991. To date, we have captured three wet-period cycles in the Guadalupe, and two in the Lavaca-Colorado, and two dry period cycles in both estuaries. 50 Lavaca-Colorado Estuary Figure 8. Long-term macrofauna biomass and salinity change in Lavaca-Colorado Estuary. Estuarine-wide average for stations A D - 51 Lavaca-Colorado Estuary Figure 9. Long-term macrofauna abundance and salinity change in Lavaca-Colorado Estuary. Estuarine-wide for stations A D average 52 Guadalupe Estuary Estuarine- Figure 10. Long-term macrofauna biomass and salinity change in Guadalupe Estuary. wide for stations A D. average 53 Guadalupe Estuary Figure 11. Long-term macrofauna abundance and salinity change in Guadalupe Estuary. Estuarine-wide for stations A D. - average 54 Figure 12. Long-term salinity change in the Lavaca-Colorado and Guadalupe Estuaries. Estuarine-wide for stations A D. average 55 Lavaca-Colorado Figure 13. Long-term salinity change and dissolved inorganic nitrogen (DIN) change in the Lavaca-Colorado Estuary. Quarterly estuarine-wide for stations A D. - average 56 Guadalupe Figure 14. Long-term salinity change and dissolved inorganic nitrogen (DIN) change in the Guadalupe Estuary. Quarterly estuarine-wide for stations A -D. average 57 Nitrogen Losses Agreatdealofnitrogenentersbaysviariverinflow(Figs. 13-14).Ifthisnitrogenis buried, then we would expect higher nitrogen values in sediments at the head ofestuaries. This is because rivers empty into the secondary bay, and more nitrogen should be trapped in the upper reaches of the bay. The trends in all Texas estuaries confirm this hypothesis (Montagna 1997). TheBaffinBay UpperLagunaMadrehaslittleriverinfluence, exceptforintermittentcreeksfed - from the tertiary bays. The effect ofeven that intermittent flow is evident in that both nitrogen (Figure 15) and carbon (Figure 16) appear to have higher concentrations in sediments in Baffin Bay (stations 6 and 24) than in Laguna Madre, which is away from the inflow sources (stations 135 and 189). Ifnitrogenisutilized, ortransformedinthebiologicallyactivelabilezone,thenthere should be higher values in upper layers ofsediment and lower values at lower layers in the refractory zone. This hypothesis is confirmed by the trends seen in the estuary-wide average nitrogen content. On average, there is a strong decrease in carbon and nitrogen values in the top 20cmofsediment,andthenvaluesarerelativelyconstantto100cmdepth(Fig. 17).Thus,the labile zone appears cm in Upper Laguna Madre (Fig. 17) as to be limited to between 0 and 20 it is in most Texas estuaries (Montagna, 1997). Nitrogen content in most Texas estuarine sediment is 0.08 to 0.15 percent at the surface, and declines to 0.04 to 0.08 percent. Lower Laguna Madre sediment is lower, but has a similar trend with 0.05 to 0.08 percent at the surface, and declines to 0.02 to 0.04 percent (Montagna, 1998). Upper Laguna Madre is nitrogen rich. The surface sediment varies from 0.3 % to 0.01. at the surface (Fig. 17). The refractory zone is only 20 cm deep. The values here confirm earlier finding that Upper Laguna Madre has a much higher nitrogen content (0.2 at the surface and 0.15 at depth) than found in Lower Laguna Madre or other Texas estuaries (Montagna, 1997). Both Upper and Lower Laguna have seagrass detritus, so itis not obvious why the Upper is higher than the Lower. Perhaps the more saline conditions in Upper Laguna Madre.are preserving nitrogen or there are unaccounted for sources.. Man can influence another key component that affects nitrogen loss. In general, it is thought that the sedimentation rate in Texas estuaries is about 1 cm per 100 years (Behrens, 1980). However, recent water projects, particularly dams, have probably decreased this rate. An average nitrogen background level, i.e., the average content at about 40 cm is about 0.05%. The average surface nitrogen content is about 0.1%, the change between the labile and refractory so zone is a factor of 2. This implies that halfofthe nitrogen arriving at the sediment surface is lost to the system via burial. This isotopic values as well as year, we used a new mass spectrometer that also measures elemental content values. Laguna Madre had lower nitrogen (6 15N) (Fig. 18) and higher carbon (6 13C) isotope values (Fig. 19) than Baffin Bay in the top 20 cm of sediment. The differences indicate the importance of seagrass productivity in producing depositional particulates in Laguna Madre relative to phytoplankton productivity in Baffin Bay On average, the vertical profile of nitrogen values varied only 1 %o indicating no change through the sediment (Fig. 20). On average, the vertical profile ofcarbon values varied 7 %o, decreasing mostly in the top 20 cm of sediment. The change in carbon values verifies that the biogenic labile zone, which is dominated by fresh plant detritus, is limited to the top 20 cm. 58 Baffin Bay - Upper Laguna Madre - Figure 15.NitrogencontentofUpperLagunaMadre BaffinBaysediments. 59 - Upper Laguna Madre Baffin Bay - Figure 16. CarboncontentofUpperLagunaMadre BaffinBaysediments. 60 - Figure 17. Average nitrogen and carbon content in Upper Laguna Madre Baffin Bay sediments 61 Upper Laguna Madre -Baffin Bay - Figure 18. Profile ofnitrogen (6 ISN) isotope values in Upper Laguna Madre Baffin Bay sediments. 62 Baffin Bay - Upper Laguna Madre - Figure 19. Profile ofcarbon (6 ,3C) isotope values in Upper Laguna Madre Baffin Bay sediments. 63 Figure 20. Average of nitrogen (6 15N)and carbon (6 13C)isotope values in Upper Laguna Madn - Baffin Bay sediments. 64 CONCLUSION The main difference between the Guadalupe and Lavaca-Colorado Estuaries relate to both sizeandGulfexchange. Freshwaterinflowhasalargerimpactonthesmaller-restricted Guadalupe Estuary than in the Lavaca-Colorado. Both the smaller size and restricted inflow have synergistic effects, thus the Guadalupe is generally fresher and has higher carbon content than the Lavaca-Colorado. These conditions lead to higher benthic productivity in the Guadalupe Estuary. a more On the other hand, higher salinities and invasion ofmarine species is responsible for diversecommunityinLavaca-ColoradoEstuary. Thereislong-term,year-to-yearvariabilityin inflow. Higher inflow introduces higher values of dissolved inorganic nitrogen, which in turn stimulates primary production. The higher primary production, which is ephemeral and changes on very short time scales (days to weeks) drives benthic production, which changes over longer times scales (three to six months). Typically, nitrogen (which is derived from inflow and processed by estuarine organisms) is lost within the top 20 cm ofsediment. Inflow also drives benthic community succession, due to different salinity tolerances of fresh, brackish, estuarine, andmarinespecies. Duetothespecieschangesandtimescalesofeffects, thesignalofinflow effects is easiest to measure and monitor using benthos as indicators. It is also apparent that longterm changes may be related to global climate cycles, e.g., El Nino events in the western Pacific Ocean. This study has benefitted by a statistical quirk (or trend) in climate data. There have been 11 El Ninos in this century, three occurred in the first halfand 8 have occurred in the second half. This short study (only 12 years) has captured three events. Because the long-term global cycles can vary from three to 20 years in length, long-term monitoring data will be required to develop reliablequantitativeestimatesofproductivityversusinflow. Becausethelastfewdecadeshave been unusually wet, estimates based on the current study are likely to be over-estimates ofthe long-term average. 65 REFERENCES Behrens, E.W. 1980. On sedimentation rates and porosity. Marine Geology Letters, 35:M11 Ml6. Folk, R. L. 1964. Petrology ofsedimentary rocks. Hemphill's Press. Austin, TX. 155 pp. Jones, R.S., J.J. Cullen, R.G. Lane, W. Yoon, R.A. Rosson, R.D. Kalke, S.A. Holt and C.R. Arnold. 1986.StudiesoffreshwaterinfloweffectsontheLavacaRiverDeltaandLavaca Bay,TX.ReporttotheTexasWaterDevelopment Board. TheUniversityofTexas Marine Science Institute, Port Aransas, TX. 423 pp. Kalke,R.D.andMontagna,P.A. 1991.Theeffectoffreshwaterinflowonmacrobenthosinthe LavacaRiverDeltaandUpper LavacaBay, Texas. ContributionsinMarineScience , 32:49-71. Montagna, P.A. 1989. Nitrogen Process Studies (NIPS): the effect offreshwater inflow on benthos communities and dynamics. Technical Report No. TR/89-011, Marine Science Institute, TheUniversityofTexas,PortAransas, TX,370pp. Montagna, P.A. 1991. Predicting long-term effects offreshwater inflow on macrobenthos in the Lavaca-Colorado and Guadalupe Estuaries. Year 2. Technical Report No. TR/91-004, Marine Science Institute, The University ofTexas, Port Aransas, TX, 78 pp. Montagna,P.A. 1997.Effectoffreshwaterinflowonmacrobenthosproductivityandnitrogen losses in Texas estuaries. Final report to Texas Water Development Board, Contract No. 97-483-199, University ofTexas Marine Science Institute Technical Report Number TR/97-02, Port Aransas, Texas. 157 pp. Montagna,P.A. 1998.Effectoffreshwaterinflowonmacrobenthosproductivityandnitrogen losses in Texas estuaries. Final report to Texas Water Development Board, Contract No. 98-483-233, University ofTexas Marine Science Institute Technical Report Number TR/98-03, Port Aransas, Texas. 62 pp. Montagna,P.A.andR.D.Kalke. 1992.TheEffectofFreshwaterInflowonMeiofaunaland Macrofaunal Populations in the Guadalupe and Nueces Estuaries, Texas. Estuaries , 15:307-326. Montagna,P.A.andR.D.Kalke. 1995.EcologyofinfaunalMolluscainsouthTexasestuaries. AmericanMalacological Bulletin 11; 163-175. Montagna, P.A., and Li, J. 1996. Modeling and monitoring long-term change in macrobenthos in Texas estuaries. Final Report to the Texas Water Devlopment Board. University of Texas at Austin, Marine Science Institute, Technical Report No. TR/96-001, Port Aransas, Texas, pp. 149 Montagna, P.A. and W.B. Yoon. 1991. The effect offreshwater inflow on meiofaunal consumption of sediment bacteria and microphytobenthos in San Antonio Bay, Texas USA. Estuarine and Coastal ShelfScience 33:529-547. , SAS Institute, Incorporated. 1985. SAS/STATGuide for Personal ComputersVersion 6 , Edition. Cary, NC;SAS Institute Inc., 378 pp. TexasDepartmentofWaterResources. 1980a. Lavaca-TresPalaciosEstuary;Astudyof influence offreshwater inflows. Publication LP-106. Texas Department ofWater Resources, Austin, Texas. 325 p. 66 Texas Department ofWater Resources. 1980b. Guadalupe Estuary; A study of influenceof freshwater inflows. Texas Department ofWater Resources, Austin, Texas. Publication LP-107. 321 p. 67 William B. Madden, Chairman Noe Fernandez, Vice-Chairman Elaine M. Barron, M.D., Member Craig D. Pedersen Jack Hunt, Member Charles L. Geren, Member Executive Administrator Wales H. Madden, Jr., Member September 29, 1999 Dr. Paul A. Montagna Research Scientist and Associate Professor University of Texas Marine Science Institute 750 Channel View Drive Port Aransas, TX 78373-5015 RE; DraftFinalReportforProject99-483-267 “EffectofFreshwaterInflowon Macrobenthos Productivity and Nutrient Losses in Texas Estuaries” Dear Dr. Montagna: I received and reviewed the draft final report “Effect of Freshwater Inflow on Macrobenthos Productivity and Nutrient Losses in Texas Estuaries.” Attached are that I noticed in the draft. I photocopies of several pages with minor typographic errors have a few other comments that are all very minor. Page 44. line 5. but abundance was highest only in July 1998.” Looking at .. to me that phrase above should say “... only in April 1999.” I Figure 4it appears noticed that the indicator “D” was missing in figures 4,5, 6, and 7. In figures 5 and 6 it is challenging to follow a few of the station patterns through time since dashed lines intersect without the “D” indicators. Page 44. line 12. (in April 1998).” The year should be 1999 instead of 1998. .. Page 44. line 14. “Stations A and B had higher abundance and biomass than stations C and D.” While the pattern described above is true for biomass for three of the four sample periods, it only appears to be true for one of the sample periods for macrofaunal abundance (Figure 7). It looks like it would be hard to generalize on a pattern for the abundance case. Page 58. lines 35-36. “Laguna Madre had lower nitrogen (ft 15N) and carbon (5 13C) isotope values than Baffin Bay.” In Figure 18, the nitrogen isotope ratios at depths below 40 cm for LMIB9 complicate the generalization that Laguna Madre has lower isotope ratios than Baffin Bay. I would agree with the generalization for depths less than 40 cm. For carbon isotopes at depths less than 40 cm, Figure 19 shows Laguna Madre samples with higher ratios than Baffin Bay. For greater depths, carbon isotope ratios for Laguna Madre ranged from values greater than Baffin Bay to values about the same as Baffin Bay. Note that figures 18,19, and 20 do not appear to be referenced in the text. ()nr Mission Provideleadership,technicalservicesandfinancialassistancetosu/fort/damnconservation,andresponsibledevelopmentofwater no. for Texas. * TO. Box .CM • I I I /()() N. Congress Avnuic Austin, lexis S7I I-CM I • * lelephone () .1) ¦(CC/.S-f Telefax OI 7) 47W.«T>3 -Will. RELAY TX Ito, the lie I I mg impaued) URI. A.ldiess: Imp://\v\v w.l wdli. stale! x.i is • E-Mail Addiess: mtoW'iwdli.si ate t\ us Tinned on Uec y» led Tapei (j) That takes care of my comments; revision of the report should be easy. Best regards, William L. Longley, Ph.D. Assistant Division Director, HEMon Division