WATERWAYS WITHIN THE SACRAMENTO-SAN JOAQUIN DELTA

Transcription

1 A WATERWAYS WITHIN THE SACRAMENTO-SAN JOAQUIN DELTA Figure A. describes all named waterways within the statutory Delta boundary. Table A. lists by code the waterway names and codes shown on Figure A.. Table A. lists by name the waterway names and codes shown on Figure A.. Delta Methylmercury TMDL A- June 00

2 Figure A.: Waterways within the Statutory Delta Boundary (see Tables A. & A. for code definitions) Delta Methylmercury TMDL A- June 00

3 Table A.: Waterways within the Statutory Delta Boundary by Code. Toe Drain. Tomato Slough. Singapore Cut. Sacramento Deep 8. Threemile Slough. Connection Slough Water Channel 9. Horseshoe Bend 8. Columbia Cut. Greens Lake 0. Mayberry Slough 9. Latham Slough. Sacramento. Mayberry Cut 0. Mildred Island. Lake Washington. Sherman Lake. Empire Cut. South Fork Putah Creek. Donlon Island. Whiskey Slough. Lake Greenhaven. Cabin Slough. Turner Cut 8. Babel Slough. Gallagher Slough. Black Slough 9. Winchester Lake. Big Break. Trapper Slough 0. Morrison Creek. Contra Costa Canal. False. Stone Lake 8. Marsh Creek. ermans Cut. Snodgrass Slough 9. Sand Creek 8. Short Slough. Elk Slough 0. Deer Creek 9. Washington Cut. Duck Slough. Dry Creek (Marsh Creek 0. Taylor Slough (near Franks. Medore Lake tributary) Tract). Sweany Creek. San Joaquin. Piper Slough. Alamo Creek. Stanislaus. Franks Tract 8. Ulatis Creek. Red Bridge Slough. Little Franks Tract 9. Cache Slough. Walthall Slough. Holland Cut 0. Hass Slough. Banta Carbona Lift Canal. Little Mandeville Cut. Lookout Slough. Lateral West. Sheep Slough. Shag Slough 8. Lateral West. Sand Mound Slough. Lindsey Slough 9. Corral Hollow Creek 8. Dutch Slough. Barker Slough 80. Upper Main Canal 9. Emerson Slough. Hastings Cut 8. Lower Main Canal 0. Rock Slough. Calhoun Cut 8. Tom Paine Slough. Werner Dredger Cut. The Big Ditch 8. Paradise Cut. Dead Dog Slough 8. Wright Cut 8. Old. Unnamed Canal(s) 9. Prospect Slough 8. Sugar Slough Between Bacon & 0. Liberty Cut 8. Crocker Cut Woodward Islands. Miner Slough 8. Salmon Slough. Indian Slough. Elkhorn Slough 88. Doughty Cut. Main Canal. Sutter Slough 89. Fabian and Bell Canal. Discovery Bay. Steamboat Slough 90. Grant Line Canal. Kellog Creek. Taylor Slough (Elkhorn Slough tributary) 9. Mountain House Creek 9. French Camp Slough 8. Canal 9. Woodward Canal. The Meadows Slough 9. Walker Slough 0. North Victoria Canal. Lost Slough 9. Burns Cutoff. Victoria Canal 8. Middle Slough 9. Stockton Deep Water. North Canal 9. Cosumnes Channel. West Canal 0. Bear Slough 9. Mormon Slough. Livermore Yacht Club. Grizzly Slough 9. Smith Canal. Italian Slough. Dry Creek (Mokelumne 98. Calaveras. Brushy Creek tributary) 99. Mokelumne Aqueduct. Clifton Court Forebay. Mokelumne 00. Fourteen Mile Slough 8. California Aqueduct. Delta Cross Channel. Dead Horse Cut. North Fork Mokelumne. South Fork Mokelumne 0. Five Mile Creek 0. Five Mile Slough 0. Mosher Slough 0. Bear Creek 0. Pixley Slough 0. Disappointment Slough 9. Delta Mendota Canal 8. Beaver Lake 0. Bishop Cut 9. Georgiana Slough 08. Telephone Cut 0. Broad Slough 09. White Slough. Beaver Slough 0. Honker Cut. Hog Slough. Little Potato Slough. Sycamore Slough. Potato Slough. Upland Canal. Little Connection Slough. Sevenmile Slough. Little Venice Island. Jackson Slough. Middle Delta Methylmercury TMDL A- June 00

4 Table A.: Waterways within the Statutory Delta Boundary by Name 8. Canal. Greens Lake. Sacramento Deep. Alamo Creek. Grizzly Slough Water Channel 8. Babel Slough 0. Hass Slough 8. Salmon Slough. Banta Carbona Lift Canal. Hastings Cut. San Joaquin. Barker Slough. Hog Slough 9. Sand Creek 0. Bear Creek. Holland Cut. Sand Mound Slough 0. Bear Slough 0. Honker Cut. Sevenmile Slough 8. Beaver Lake 9. Horseshoe Bend. Shag Slough. Beaver Slough. Indian Slough. Sheep Slough. Big Break. Italian Slough. Sherman Lake 0. Bishop Cut. Jackson Slough 8. Short Slough. Black Slough. Kellog Creek. Singapore Cut 0. Broad Slough. Lake Greenhaven 9. Smith Canal. Brushy Creek. Lake Washington. Snodgrass Slough 9. Burns Cutoff. Lateral West. South Fork Mokelumne. Cabin Slough 8. Lateral West 9. Cache Slough 9. Latham Slough. South Fork Putah Creek 98. Calaveras 0. Liberty Cut. Stanislaus. Calhoun Cut. Lindsey Slough. Steamboat Slough 8. California Aqueduct. Clifton Court Forebay. Little Connection Slough. Little Franks Tract 9. Stockton Deep Water Channel 8. Columbia Cut. Little Mandeville Cut. Stone Lake. Connection Slough. Little Potato Slough 8. Sugar Slough. Contra Costa Canal. Little Venice Island. Sutter Slough 9. Corral Hollow Creek. Livermore Yacht Club. Sweany Creek 9. Cosumnes. Lookout Slough. Sycamore Slough 8. Crocker Cut. Lost Slough. Taylor Slough (Elkhorn. Dead Dog Slough. Dead Horse Cut 8. Lower Main Canal. Main Canal Slough tributary) 0. Taylor Slough (near Franks 0. Deer Creek 8. Marsh Creek Tract). Delta Cross Channel. Mayberry Cut 08. Telephone Cut 9. Delta Mendota Canal 0. Mayberry Slough. The Big Ditch 0. Disappointment Slough. Medore Lake. The Meadows Slough. Discovery Bay. Middle 8. Threemile Slough. Donlon Island 8. Middle Slough. Toe Drain 88. Doughty Cut 0. Mildred Island 8. Tom Paine Slough. Dry Creek (Marsh Creek. Miner Slough. Tomato Slough tributary) 99. Mokelumne Aqueduct. Trapper Slough. Dry Creek (Mokelumne. Mokelumne. Turner Cut tributary) 9. Mormon Slough 8. Ulatis Creek. Duck Slough 0. Morrison Creek. Unnamed Canal(s) 8. Dutch Slough 0. Mosher Slough Between Bacon &. Elk Slough 9. Mountain House Creek Woodward Islands. Elkhorn Slough. North Canal. Upland Canal 9. Emerson Slough. Empire Cut. North Fork Mokelumne 80. Upper Main Canal. Victoria Canal 89. Fabian and Bell Canal 0. North Victoria Canal 9. Walker Slough. False 8. Old. Walthall Slough. ermans Cut 8. Paradise Cut 9. Washington Cut 0. Five Mile Creek 0. Five Mile Slough 00. Fourteen Mile Slough. Piper Slough 0. Pixley Slough. Potato Slough. Werner Dredger Cut. West Canal. Whiskey Slough. Franks Tract 9. Prospect Slough 09. White Slough 9. French Camp Slough. Red Bridge Slough 9. Winchester Lake. Gallagher Slough 0. Rock Slough 9. Woodward Canal 9. Georgiana Slough. Sacramento 8. Wright Cut 90. Grant Line Canal Delta Methylmercury TMDL A- June 00

5 B SUMMARY OF FISH MERCURY DATA USED IN TMDL NUMERIC TARGET AND LINKAGE ANALYSIS CALCULATIONS Section B. summarizes the fish mercury data used in the numeric target and linkage analysis chapters. Table B. lists the fish species and lengths of fish included in the weighted-average fish mercury concentrations. Tables B. through B. list the number of samples and fish included in the calculations for each Delta subregion. Data for fish sampled in the Cosumnes and Mokelumne and in the northern portion of the Yolo Bypass were included in the numeric target development calculations. However, only data for fish sampled in the Mokelumne downstream of the Cosumnes confluence were included in the linkage analysis calculations; these data are summarized in Tables B. and B.. All fish data summarized in these tables are provided in Appendix L. Section B. provides figures that illustrate the range of mercury levels in the species within each Delta subregion trophic level food group. Appendix C provides a description of the available mercury data for important commercial and sport fisheries such as striped bass, salmon, crayfish, clams and blackfish not included in this data summary because they either do not represent local conditions or do not fit within the trophic level food groups defined by the numeric targets. Weighted average mercury concentration is based on the number of fish in the composite samples analyzed, rather than the number of samples. Delta Methylmercury TMDL B- June 00

6 B. Description of Mercury DATA Used in the Numeric Target and Linkage Analysis Chapters Table B.: Summary of Species & Lengths Used in the Numeric Target & Linkage Analysis Chapters Trophic Level Species & Length Ranges Used for Estimation of Human & Bald Eagle Health Risk [0-00 mm, unless CDFG minimum catch limit applies] (a,b) Black crappie (> 0 mm) Channel catfish (> 00 mm) (b) Largemouth bass (> 0 mm) (a) Sacramento pikeminnow (> 0 mm) (b) Smallmouth bass (> 0 mm) (a) White catfish (> 00 mm) (b) White crappie (> 0 mm) (b) Trophic Level Species & Length Ranges Used for Estimation of Otter and Osprey Health Risk (c) Black crappie (0-0 mm) Channel catfish (00-0 mm) Largemouth bass (0-0 mm) Sacramento pikeminnow (0-0 mm) Smallmouth bass (0-0 mm) White catfish (00-0 mm) White crappie (0-0 mm) Trophic Level Species & Length Ranges Used for Estimation of Human Health and Bald Eagle Risk [0-00 mm] (d) Black bullhead Bluegill Carp Channel catfish (0-00 mm) Golden shiner Goldfish (e) Redear sunfish Sacramento blackfish Sacramento splittail Sucker Unid goby White catfish (0-00 mm) Yellowfin goby Trophic Level Species & Length Ranges for Estimation of Osprey, Grebe and Merganser Health Risk. [All TL fish species, 0-0 mm. Small individuals of TL species of catfish are included.] (c) Black bullhead Bluegill Carp Channel catfish (0-00 mm) Golden shiner Goldfish Redear sunfish Sacramento blackfish Sacramento splittail Sucker Threadfin Shad Unid goby White catfish (0-00 mm) Yellowfin goby Trophic Level Species & Length Ranges for Estimation of Cormorant, Otter, Mink and Kingfisher Health Risk. [All TL fish species, 0-0 mm. Small individuals of TL species of bass, crappie, and catfish, are included.] (f) Bigscale logperch Bluegill Channel catfish (0-0 mm) Golden shiner Inland silverside Largemouth bass (0-00 mm) Mosquitofish Prickly sculpin Red shiner Redear sunfish Shimofuri goby Threadfin Shad Unid goby White catfish (0-0 mm) White crappie (0-0 mm) Yellowfin goby Trophic Level for Estimation of Least Tern Health Risk. [All TL and juveniles of TL fish species less than 0 mm.] (g) Bluegill Inland silverside Mosquitofish Prickly sculpin Red shiner Shimofuri goby White catfish White crappie Delta Methylmercury TMDL B- June 00

7 TABLE B. FOOTNOTES: (a) Size minimum based on CDFG fishing regulations: inch minimum (0 mm) for largemouth and smallmouth bass. (b) Size minimum based on prey type of the fish species. Example: on average, catfish 00 mm and larger are mainly piscivorous, meaning that a majority of their diet is trophic level three species. Catfish smaller than 00 mm eat mainly prey from trophic level. Minimum sizes based on length of fish when they become mostly piscivorous are given for bass, catfish, pikeminnow and crappie (Source: Moyle PB, 00. Inland es of California, Revised and Expanded, Berkeley, Univ. California Press) (c) Size minimum based on prey type of the fish species - see note (b). Maximum size of 0 mm is based on largest size generally consumed by osprey or otter. (For bald eagle, use average concentration in TL fish grouped for humans to assess risk). (d) TL species for calculating human health risk are those species assumed to be eaten by humans, based on general knowledge of the fishery and size of fish. Staff assumes that most fish eaten are at least 0 mm ( inches). Small bass are not included in the trophic level species for human consumption because they cannot legally be fished and kept. Crappies are not included because juvenile crappies (TL) are generally less than 0 mm. (e) Although goldfish is a TL species, large ones may be consumed by humans and are included to estimate human risk. Only one Delta goldfish was analyzed for mercury. (f) length range of 0-0 mm based on the size of fish typically consumed by kingfisher, cormorant and mink (USFWS, 00). (g) Size maximum of 0 mm based on general size limit of prey consumed by California least terns (USFWS, 00). Delta Methylmercury TMDL B- June 00

8 Table B.: Number of Composite and the Total Number of in the Composite Used to Estimate the Weighted Average Trophic Level and Mercury Concentrations for Human and Eagle Health Risk Assessments (a) Trophic Level (Length Range) / Species Central Delta Cosumnes Mokelumne R. d/s Cosumnes R. Sacramento San Joaquin West Delta Yolo Bypass- North Yolo Bypass- South Total TL (0-0 mm) Channel Catfish 0 Crappie 9 0 Largemouth Bass Sacramento Pike Minnow 8 Smallmouth Bass White Catfish TL (0-0 mm) Black Bullhead Bluegill Carp Redear Sunfish 9 0 Sacramento Blackfish Sacramento Splittail Sacramento Sucker White Catfish (a) TOTAL Cosumnes and Yolo Bypass-North fish data were used in the Delta-wide numeric target evaluation (Chapter ) but not in the linkage analysis because aqueous methylmercury samples were not collected in these subregions. Marsh Creek fish samples collected upstream of any tidal influence, although within the statutory Delta boundary, were not used in any Delta TMDL evaluations because a separate TMDL effort will be conducted for the Marsh Creek watershed. No fish data that met the data use rules described in Section.. were available for the Mokelumne upstream of the Cosumnes confluence. Total # of Delta Methylmercury TMDL B- June 00

9 Table B.: Number of Composite and the Total Number of in the Composite Used to Estimate the Weighted Average Trophic Level and Mercury Concentrations for Wildlife Health Risk Assessments (a) Trophic Level (Length Range) / Species Central Delta Cosumnes Mokelumne R. d/s Cosumnes R. Sacramento San Joaquin West Delta Yolo Bypass- North Yolo Bypass- South Total TL (0-0 mm) Crappie 9 0 Largemouth Bass Sacramento Pike Minnow 0 Smallmouth Bass White Catfish 8 TL (0-0 mm) Black Bullhead Bluegill 0 Golden Shiner Redear Sunfish 8 Sacramento Blackfish Sacramento Sucker Threadfin Shad Unid Goby White Catfish Yellowfin Goby TL (0-0 mm) Bigscale Logperch Bluegill Golden Shiner 0 8 Largemouth Bass Mosquitofish Prickly Sculpin 8 9 Red Shiner 9 Redear Sunfish Shimofuri Goby 9 0 Total # of Delta Methylmercury TMDL B- June 00

10 Table B.: Number of Composite and the Total Number of in the Composite Used to Estimate the Weighted Average Trophic Level and Mercury Concentrations for Wildlife Health Risk Assessments (a) Trophic Level (Length Range) / Species Central Delta Cosumnes Mokelumne R. d/s Cosumnes R. Sacramento San Joaquin West Delta Yolo Bypass- North Yolo Bypass- South Total Silverside Threadfin Shad Unid Goby White Catfish White Crappie Yellowfin Goby TL (<0 mm) Bluegill Mosquitofish Prickly Sculpin Red Shiner 0 Shimofuri Goby Silverside Threadfin Shad 0 99 White Catfish White Crappie (a) TOTAL Cosumnes and Yolo Bypass-North fish data were used in the Delta-wide numeric target evaluation (Chapter ) but not in the linkage analysis because aqueous methylmercury samples were not collected in these subregions. Marsh Creek fish samples collected upstream of any tidal influence, although within the statutory Delta boundary, were not used in any Delta TMDL evaluations because a separate TMDL effort will be conducted for the Marsh Creek watershed. No fish data that met the data use rules described in Section.. were available for the Mokelumne upstream of the Cosumnes confluence. Total # of Delta Methylmercury TMDL B- June 00

11 B. Range of Mercury Levels in Species Present in Each Delta Subregion This section provides graphs that show the range of mercury levels in Delta species by trophic level, species, and Delta subregion evaluated in the numeric target and linkage analyses: Figure B.: TL Food Group (0-00 mm) Mercury Levels Figure B.: TL Food Group (0-00 mm) Mercury Levels Figure B.: TL Food Group (0-0 mm) Mercury Levels Figure B.: TL Food Group (0-0 mm) Mercury Levels Figure B.: TL Food Group (0-0 mm) Mercury Levels Figure B.: TL Food Group (<0 mm) Mercury Levels Delta Methylmercury TMDL B- June 00

12 Central Delta Mokelumne Sacramento San Joaquin Yolo Bypass (South).. 0. Channel Catfish Crappie Largemouth Bass Sacramento Pike Minnow Smallmouth Bass White Catfish West Delta.. 0. Channel Catfish Crappie Largemouth Bass Sacramento Pike Minnow Smallmouth Bass White Catfish Figure B.: TL Food Group (0-00 mm) Mercury Levels Delta Methylmercury TMDL B-8 June 00

13 Central Delta Mokelumne Sacramento San Joaquin West Delta Yolo Bypass (South) Black Bullhead Bluegill Carp Redear Sunfish Sacramento Blackfish Sacramento Splittail Sacramento Sucker White Catfish Black Bullhead Bluegill Carp Redear Sunfish Sacramento Blackfish Sacramento Splittail Sacramento Sucker White Catfish Figure B.: TL Food Group (0-00 mm) Mercury Levels Delta Methylmercury TMDL B-9 June 00

14 Central Delta Mokelumne Sacramento San Joaquin Yolo Bypass (South). 0. Crappie Largemouth Bass Sacramento Pike Minnow Smallmouth Bass White Catfish West Delta. 0. Crappie Largemouth Bass Sacramento Pike Minnow Smallmouth Bass White Catfish Figure B.: TL Food Group (0-0 mm) Mercury Levels Delta Methylmercury TMDL B-0 June 00

15 Central Delta Mokelumne Sacramento San Joaquin Yolo Bypass (South) Black Bullhead Bluegill Golden Shiner Redear Sunfish Sacramento Blackfish Sacramento Sucker Threadfin Shad Unid Goby White Catfish Yellow fin Goby West Delta No data available for this trophic level/size category/ Black Bullhead Bluegill Golden Shiner Redear Sunfish Sacramento Blackfish Sacramento Sucker Threadfin Shad Unid Goby White Catfish Y ellow f in Goby Figure B.: TL Food Group (0-0 mm) Mercury Levels Delta Methylmercury TMDL B- June 00

16 Central Delta Mokelumne Sacramento San Joaquin West Delta Yolo Bypass (South) Figure B.: TL Food Group (0-0) Mercury Levels Delta Methylmercury TMDL B- June 00

17 Central Delta Mokelumne Sacramento San Joaquin Yolo Bypass (South) Bluegill Mosquitofish Prickly Sculpin Red Shiner Shimofuri Goby Silverside Threadfin Shad West Delta Bluegill Mosquitofish Prickly Sculpin Red Shiner Shimofuri Goby Silverside Threadfin Shad Figure B.: TL Food Group (<0 mm) Mercury Levels Delta Methylmercury TMDL B- June 00

18 C COMMERCIAL AND SPORT FISHING IN THE SACRAMENTO-SAN JOAQUIN DELTA As noted in Chapter, the Basin Plan lists the existing and potential uses of the Delta. The Basin Plan provides a standard definition for commercial and sport fishing (COMM). The COMM designation is defined as uses of water for commercial or recreational collection of fish, shellfish, or other organisms including, but not limited to, uses involving organisms intended for human consumption or bait purposes (CVRWQCB, 998). The current Basin Plan does not include the commercial and sport fishing (COMM) designation for the Sacramento-San Joaquin Delta. However, commercial and sport fishing is a past and present use of the Delta. The Delta provides habitat for as many as forty freshwater, saltwater and anadromous fishes (Moyle, 00). Several sport fishes reside in the Delta, including striped bass, black bass (e.g., largemouth and smallmouth bass), sturgeon, Chinook salmon, American shad, and catfish. and other aquatic organisms also are collected commercially. CDFG issues commercial fishing licenses in California and reports active commercial fishing in the Delta. Bulk historic commercial fishing data were not available; CDFG s Marine Resources website provides summary data for commercial landings and associated values for fishing years 00 and 00 (Table C.). The predominant species targeted include bay shrimp, crayfish and threadfin shad. Threadfin shad are used mainly as baitfish for catching striped bass. Sport and subsistence fishing is common throughout the Delta and takes place year round. On average, sport fishing license sales in the six Delta counties account for 9% of all licenses issued in the State (Table C.). It is unknown what portion of those licenses was purchased for fishing within the statutory Delta boundary. However, creel surveys and interviews indicate that sport and subsistence anglers actively fish the Delta waterways year-round by boat and from banks. CDFG s creel surveys indicate that a variety of species are caught and kept (Table C., Figure C.). CDHS Environmental Health Investigations Branch staff conducted interviews of selected groups in the Delta region and found that members of several communities regularly eat local fish, especially striped bass and catfish (CDHS, 00). Several fishing derbies for striped bass, black bass and sturgeon take place in the Delta every year. In addition to the species listed in Tables C. and C., Sacramento blackfish, shimofuri goby and clams may also be collected from the Delta (Moyle, 00; anecdotal information). However, the CDFG creel surveys (CDFG, ) and anecdotal information provided by CDFG staff (T. Schroyer, CDFG, personal communication to J. Cooke) indicate that many Delta anglers target salmon, sunfish, striped bass, largemouth bass and catfish and are unlikely to take home clams and shrimp species. Mercury data from Delta sampling efforts (Table C.) are available for all of the species listed in Tables C. and C. (or for similar species) except hitch, longjaw mudsucker, rainbow and steelhead trout, starry flounder, American shad and salmon. Except for American shad and salmon, these species do not appear to be key commercial and sport fish in the Delta. To evaluate American shad and salmon mercury levels for impairment, data from additional Suisun Bay, San Francisco Bay and Delta tributary locations were reviewed. Because salmon are anadromous and spend the majority of their lives in the Pacific Ocean, salmon that are caught in the Delta will most likely have mercury levels similar to those caught upstream in the tributary watersheds. The same is likely true for American shad. Table C. includes mercury data for American shad and Chinook salmon collected in the Delta and its upstream tributaries. Per CDFG fishing regulations, some Delta fish species have size limits: Black bass (e.g., largemouth and smallmouth bass) minimum inches (0 mm); Striped bass minimum 8 inches ( mm); and Sturgeon between and inches (,8 to,89 mm) Delta Methylmercury TMDL C- June 00

19 Only samples collected from the tissue (fillet) of fish that met the size limits for these species were included in Table C.. For other sport fish, only tissue samples collected from fish greater than 00 mm were included. Both fillet and whole fish samples were included for all sizes of threadfin shad, which is used as bait. In addition, all sizes of crayfish and clams were included. Data summarized in Table C. were collected between 90 and 00. The Delta-wide weighted average mercury levels in each species were compared to the USEPA criterion for the protection of human health of 0. mg/kg and the FDA action level for commercially caught fish of.0 mg/kg (Figure C.). Although many individual samples had mercury levels that exceeded the FDA action level, none of species-specific weighted average mercury concentrations exceeded the action level. In addition, none of the species for which commercial fishing licenses were issued exceeded the USEPA criterion. However, the average mercury concentrations of several sport fish sturgeon, catfish, crappie, Sacramento splittail, Sacramento pike minnow, largemouth bass, small bass, and striped bass approached or exceeded the USEPA criterion. The bass had the highest average mercury concentrations of any species. Largemouth bass had mercury levels comparable to striped bass mercury levels. The linkage analyses described in Chapter and fish data described in Appendix B are based on samples collected between 998 and 00 for species that represent local conditions and fit within the trophic level food groups defined by the numeric targets (Chapter ). All of the species listed in Table C. and Figure C. were addressed by the numeric target development and linkage analysis (Chapters and, Appendix B), except American shad, Asiatic and resident freshwater clams, chinook salmon, Crangon shrimp, crayfish, striped bass and sturgeon. Of these, only striped bass and sturgeon had average mercury concentrations that exceeded the USEPA criterion of 0. mg/kg. As methyl and total mercury reduction efforts take place and the numeric targets are approached throughout the Delta for the species described in Appendix B, striped bass and sturgeon data also will be re-evaluated for compliance with the USEPA criterion and other adopted, Delta-specific water quality objectives. Table C.: Commercial eries Landings in the Sacramento-San Joaquin Delta and Associated Value (a) Landings (pounds) Value Species Bay shrimp 9,09 9, $,9 $,9 Carp $ Crayfish 00,008 08, $0,0 $, Hitch 0 $0 Longjaw mudsucker 9 $0 Threadfin shad,9 9, $,8 $,08 Yellowfin goby 8 $ TOTAL:,00, $,9 $,889 (a) Source: Delta Methylmercury TMDL C- June 00

20 Table C.: Average Number of Sport ing Licenses Issued in Six Delta Counties (a,b) County Resident Licenses Striped Bass Tag Salmon Tag Steelhead Tag Alameda,0, Contra Costa,0,98 80 Sacramento 89,,0, San Joaquin,0,90 8 Solano,8 9, 9 Yolo 9,9, 0 9 (a) (b),09,0 Total for Delta Counties:,9,9, 9, Total for California:,,9,8 9,9,8 % Delta Licences: 9% % 8% % Source: Resident fish licenses and salmon tags are averaged over a 0-year period, striped bass averaged over years, and steelhead averaged over 8 years. 8 Table C.: Sum of Kept by Delta Anglers per the CDFG s Central Valley Angler Surveys for 999 and 000. (a) (a) Species [Acronym Used in Figure C.] Trophic Level Kept Catfish [CF] 0 Striped Bass [SB] 9 Chinook Salmon [a.k.a. king salmon, KS] 8 American Shad [AS] 9 Splittail [SPT] 9 Sunfish [SF] Black Bass [BB] Sturgeon [ST] 9 Starry Flounder [STF] Sacramento Pikeminnow [SPM] Common Carp [CP] 0 Steelhead Trout [SH] Sacramento Sucker [SKR] Rainbow trout [RT] Data obtained from Fraser Shilling (University of California, Davis), who requested the query of actual reported number of fish kept and released by species and river mile from the CDFG Creel Database for the 999 and 000 Central Valley Angler Surveys 999 and 000. A summary of fish kept by Delta subregion is shown in Figure C.. Delta Methylmercury TMDL C- June 00

21 TROPHIC LEVEL SPECIES TROPHIC LEVEL SPECIES Central Delta Kept Kept Mokelumne/Cosumnes s 0 0 Kept Kept 0 0 Sacramento Kept Kept San Joaquin Kept Kept West Delta AS CP KS RT SF SH SKR SPT ST STF 000 Kept Kept BB CF SB SPM Figure C.: Sum of Kept by Delta Anglers by Delta Subregion per the CDFG s Central Valley Angler Surveys for 999 and 000. (Species acronyms are defined in Table C..) Delta Methylmercury TMDL C- June 00

22 Table C.: Summary of Available Mercury Concentration Data for Species Targeted by Sport and Commercial ing (a,b,c) Common Min Hg Conc. (mg/kg) Ave Hg Conc. (mg/kg) Max Hg Conc. (mg/kg) Weighted Ave (mg/kg) American Shad Black Bullhead Black Crappie Bluegill Carp Catfish Channel Catfish Chinook Salmon Clam, Asiatic Clam, Resident Freshwater 0 (a) (b) (c) Crangon Shrimp Crappie Crayfish Largemouth Bass Redear Sunfish Sacramento Blackfish Sacramento Pike Minnow Sacramento Splittail Sacramento Sucker Shimofuri Goby Smallmouth Bass Striped Bass Sturgeon Threadfin Shad White Catfish Yellowfin Goby CDFG's legal limit is inch minimum (0 mm) for largemouth and smallmouth bass, 8 inch minimum ( mm) for striped bass, and between and inches (,8 to,89 mm) for sturgeon; only data collected from tissue (fillet) samples were included. For other sport fish, only tissue samples collected from fish greater than 00 mm were included. Both fillet and whole fish samples were included for all sizes of threadfin shad, which is typically used as bait. In addition, all sizes of crayfish and clams were included. Results represent total mercury, wet weight concentrations. Little-to-no mercury data were available for adult salmon and American shad caught in the Delta. To evaluate salmon mercury levels for impairment, data from Suisun Bay and Delta s tributary watersheds were reviewed. Because salmon are anadromous (they spend the majority of their lives in the Pacific Ocean and return to fresh waters only to spawn) adult salmon (typically >0 mm) that are caught in the Delta most likely have mercury levels similar to those caught elsewhere in the Bay-Delta and tributary watersheds. The same is likely true for American shad. American shad samples were collected from the American, Sacramento downstream of the Feather confluence, and Suisun Bay. Chinook salmon samples were collected from the upper Sacramento near Red Bluff, American, Sacramento at Mile and San Francisco Bay. Data summarized in this table were collected between 90 and 00. In contrast, the numeric target development and linkage analyses are based on data collected between 998 and 00. Delta Methylmercury TMDL C- June 00

23 . Mercury Concentration (mg/kg, w et w eight) FDA Action Level (.0 mg/kg) USEPA Criterion (0. mg/kg) Figure C.: Minimum, Maximum and Weighted Average Mercury Concentrations in Species Targeted by Sport and Commercial ing Based on Available Data Delta Methylmercury TMDL C- June 00