Bay Delta Region
Studies and Surveys
- 20mm Survey
- Fall Midwater Trawl
- Fish Salvage Monitoring
- San Francisco Bay Study
- Smelt Larva Survey
- Special Studies
- Spring Kodiak Trawl
- Striped Bass Study
- Sturgeon Study
- Townet Survey
- Zooplankton Study
- All Surveys and Studies
Other BDR Links
Main Office
2825 Cordelia Road, Suite 100
Fairfield, CA 94534
(707) 428-2002
Stockton Office
2109 Arch Airport Rd
Stockton, CA 95206
(209) 234-3420
Acting Regional Manager:
Scott Wilson
Related Programs
Monthly Abundance Indices
Fall Midwater Trawl indices for age-0 striped bass (Morone saxatilis), delta smelt (Hypomesus transpacificus), longfin smelt (Spirinchus thaleichthys), American shad (Alosa sapidissima),splittail (Pogonichthys macrolepidotus), and threadfin shad (Dorosoma petenense) from 1967-2022; please note that no surveys were done in 1974, 1979, and September and December 1976.
The September 1976 index was calculated by taking a quotient of the respective September and October indices (September/October) for pre-Corbula amurensis years 1967-1973, 1975, 1977-1978, 1980-1987 then averaging the quotients.
This mean quotient was then multiplied by the respective 1976 October index to generate the September index. The 1976 December index was calculated for each species by averaging the 1976 November and 1977 January indices.
In addition, due to the low number of stations sampled in Nov. 1969, the 1969 Nov. index is the average of the October and December 1969 index.
Year | Sept | Oct | Nov | Dec | Total |
---|---|---|---|---|---|
1967 | 11941 | 3681 | 1789 | 2266 | 19677 |
1968 | 1633 | 1160 | 602 | 324 | 3719 |
1969 | 3894 | 1548 | 1393 | 1237 | 8072 |
1970 | 2277 | 1817 | 2750 | 1432 | 8276 |
1971 | 3992 | 1837 | 1351 | 2295 | 9475 |
1972 | 3160 | 974 | 1377 | 605 | 6116 |
1973 | 1516 | 441 | 1005 | 1324 | 4286 |
1974 | |||||
1975 | 1772 | 681 | 1284 | 811 | 4548 |
1976 | 239 | 117 | 243 | 821 | 1420 |
1977 | 307 | 204 | 180 | 192 | 883 |
1978 | 1115 | 561 | 336 | 586 | 2598 |
1979 | |||||
1980 | 739 | 384 | 102 | 268 | 1493 |
1981 | 583 | 916 | 1037 | 1995 | 4531 |
1982 | 1476 | 938 | 939 | 1113 | 4466 |
1983 | 1934 | 1994 | 5272 | 3273 | 12473 |
1984 | 1287 | 2666 | 1374 | 1254 | 6581 |
1985 | 125 | 825 | 58 | 752 | 1760 |
1986 | 2706 | 532 | 508 | 197 | 3943 |
1987 | 603 | 169 | 206 | 372 | 1350 |
1988 | 106 | 98 | 129 | 144 | 477 |
1989 | 154 | 152 | 76 | 60 | 442 |
1990 | 234 | 235 | 397 | 454 | 1320 |
1991 | 262 | 128 | 115 | 439 | 944 |
1992 | 620 | 246 | 544 | 632 | 2042 |
1993 | 508 | 513 | 281 | 254 | 1556 |
1994 | 206 | 188 | 206 | 659 | 1259 |
1995 | 116 | 131 | 141 | 90 | 478 |
1996 | 71 | 46 | 32 | 243 | 392 |
1997 | 287 | 143 | 69 | 69 | 568 |
1998 | 234 | 290 | 126 | 574 | 1224 |
1999 | 154 | 68 | 134 | 185 | 541 |
2000 | 93 | 154 | 90 | 51 | 388 |
2001 | 181 | 217 | 114 | 219 | 731 |
2002 | 18 | 20 | 15 | 20 | 73 |
2003 | 34 | 34 | 25 | 18 | 111 |
2004 | 16 | 17 | 6 | 15 | 54 |
2005 | 40 | 29 | 26 | 26 | 121 |
2006 | 236 | 18 | 39 | 70 | 363 |
2007 | 32 | 34 | 14 | 2 | 82 |
2008 | 57 | 39 | 85 | 39 | 220 |
2009 | 9 | 23 | 14 | 24 | 70 |
2010 | 16 | 5 | 11 | 11 | 43 |
2011 | 112 | 62 | 30 | 68 | 272 |
2012 | 20 | 16 | 14 | 75 | 125 |
2013 | 18 | 5 | 13 | 34 | 70 |
2014 | 8 | 2 | 4 | 45 | 59 |
2015 | 4 | 8 | 11 | 29 | 52 |
2016 | 43 | 4 | 5 | 72 | 124 |
2017 | 43 | 118 | 146 | 163 | 470 |
2018 | 4 | 16 | 9 | 13 | 42 |
2019 | 84 | 43 | 60 | 68 | 255 |
2020 | 10 | 2 | 16 | 24 | 52 |
2021 | 1 | 10 | 40 | 5 | 56 |
2022 | 10 | 34 | 11 | 11 | 66 |
Year | Sept | Oct | Nov | Dec | Total |
---|---|---|---|---|---|
1967 | 94 | 157 | 31 | 126 | 408 |
1968 | 235 | 252 | 123 | 86 | 696 |
1969 | 148 | 78 | 55 | 32 | 313 |
1970 | 742 | 342 | 82 | 507 | 1673 |
1971 | 197 | 471 | 428 | 207 | 1303 |
1972 | 572 | 470 | 81 | 142 | 1265 |
1973 | 308 | 312 | 198 | 327 | 1145 |
1974 | |||||
1975 | 290 | 214 | 102 | 91 | 697 |
1976 | 69 | 42 | 121 | 127 | 359 |
1977 | 98 | 242 | 52 | 88 | 480 |
1978 | 167 | 65 | 31 | 309 | 572 |
1979 | |||||
1980 | 370 | 274 | 587 | 423 | 1654 |
1981 | 132 | 27 | 54 | 161 | 374 |
1982 | 45 | 47 | 79 | 162 | 333 |
1983 | 2 | 28 | 78 | 24 | 132 |
1984 | 47 | 44 | 67 | 24 | 182 |
1985 | 41 | 24 | 28 | 17 | 110 |
1986 | 92 | 15 | 34 | 71 | 212 |
1987 | 71 | 40 | 69 | 100 | 280 |
1988 | 58 | 67 | 19 | 30 | 174 |
1989 | 88 | 75 | 158 | 45 | 366 |
1990 | 109 | 50 | 188 | 17 | 364 |
1991 | 126 | 249 | 279 | 35 | 689 |
1992 | 72 | 3 | 57 | 24 | 156 |
1993 | 375 | 470 | 94 | 139 | 1078 |
1994 | 65 | 12 | 7 | 18 | 102 |
1995 | 120 | 349 | 352 | 78 | 899 |
1996 | 19 | 23 | 13 | 72 | 127 |
1997 | 15 | 109 | 71 | 108 | 303 |
1998 | 238 | 97 | 15 | 70 | 420 |
1999 | 198 | 380 | 114 | 172 | 864 |
2000 | 430 | 128 | 56 | 142 | 756 |
2001 | 75 | 481 | 17 | 30 | 603 |
2002 | 20 | 46 | 29 | 44 | 139 |
2003 | 15 | 136 | 17 | 42 | 210 |
2004 | 26 | 18 | 23 | 7 | 74 |
2005 | 3 | 9 | 7 | 7 | 26 |
2006 | 33 | 3 | 4 | 1 | 41 |
2007 | 9 | 4 | 5 | 10 | 28 |
2008 | 2 | 5 | 12 | 4 | 23 |
2009 | 1 | 3 | 3 | 10 | 17 |
2010 | 6 | 12 | 0 | 11 | 29 |
2011 | 50 | 54 | 23 | 216 | 343 |
2012 | 0 | 23 | 12 | 7 | 42 |
2013 | 4 | 3 | 2 | 9 | 18 |
2014 | 4 | 4 | 0 | 1 | 9 |
2015 | 5 | 0 | 0 | 2 | 7 |
2016 | 0 | 0 | 8 | 0 | 8 |
2017 | 0 | 2 | 0 | 0 | 2 |
2018 | 0 | 0 | 0 | 0 | 0 |
2019 | 0 | 0 | 0 | 0 | 0 |
2020 | 0 | 0 | 0 | 0 | 0 |
2021 | 0 | 0 | 0 | 0 | 0 |
2022 | 0 | 0 | 0 | 0 | 0 |
Year | Sept | Oct | Nov | Dec | Total |
---|---|---|---|---|---|
1967 | 15484 | 49992 | 7480 | 8781 | 81737 |
1968 | 1408 | 771 | 446 | 654 | 3279 |
1969 | 35797 | 9845 | 7851 | 5857 | 59350 |
1970 | 889 | 410 | 1056 | 4160 | 6515 |
1971 | 2388 | 5722 | 5019 | 2774 | 15903 |
1972 | 138 | 118 | 106 | 398 | 760 |
1973 | 2794 | 1237 | 808 | 1057 | 5896 |
1974 | |||||
1975 | 318 | 598 | 1198 | 705 | 2819 |
1976 | 15 | 12 | 90 | 541 | 658 |
1977 | 29 | 17 | 83 | 81 | 210 |
1978 | 1744 | 1173 | 1450 | 2252 | 6619 |
1979 | |||||
1980 | 15233 | 6071 | 3526 | 6354 | 31184 |
1981 | 222 | 398 | 179 | 1403 | 2202 |
1982 | 7898 | 13961 | 28171 | 12875 | 62905 |
1983 | 152 | 3106 | 5407 | 3199 | 11864 |
1984 | 328 | 2612 | 2551 | 1917 | 7408 |
1985 | 20 | 31 | 219 | 722 | 992 |
1986 | 972 | 1543 | 1857 | 1788 | 6160 |
1987 | 134 | 70 | 384 | 932 | 1520 |
1988 | 16 | 17 | 207 | 551 | 791 |
1989 | 11 | 32 | 37 | 376 | 456 |
1990 | 10 | 1 | 81 | 151 | 243 |
1991 | 8 | 7 | 27 | 92 | 134 |
1992 | 3 | 0 | 12 | 61 | 76 |
1993 | 99 | 112 | 128 | 459 | 798 |
1994 | 4 | 10 | 79 | 452 | 545 |
1995 | 5430 | 931 | 1516 | 328 | 8205 |
1996 | 2 | 27 | 14 | 1303 | 1346 |
1997 | 106 | 51 | 194 | 339 | 690 |
1998 | 149 | 1578 | 2032 | 2895 | 6654 |
1999 | 1953 | 2736 | 331 | 223 | 5243 |
2000 | 1635 | 48 | 938 | 816 | 3437 |
2001 | 74 | 46 | 27 | 100 | 247 |
2002 | 127 | 144 | 182 | 254 | 707 |
2003 | 10 | 62 | 77 | 318 | 467 |
2004 | 44 | 9 | 9 | 129 | 191 |
2005 | 1 | 22 | 13 | 93 | 129 |
2006 | 1563 | 169 | 184 | 33 | 1949 |
2007 | 2 | 0 | 2 | 9 | 13 |
2008 | 0 | 19 | 43 | 77 | 139 |
2009 | 0 | 8 | 10 | 47 | 65 |
2010 | 2 | 7 | 4 | 178 | 191 |
2011 | 68 | 16 | 92 | 301 | 477 |
2012 | 6 | 2 | 17 | 36 | 61 |
2013 | 8 | 28 | 21 | 107 | 164 |
2014 | 6 | 3 | 5 | 2 | 16 |
2015 | 0 | 0 | 0 | 4 | 4 |
2016 | 3 | 0 | 2 | 2 | 7 |
2017 | 6 | 23 | 25 | 87 | 141 |
2018 | 13 | 5 | 8 | 26 | 52 |
2019 | 11 | 2 | 4 | 27 | 44 |
2020 | 0 | 0 | 22 | 6 | 28 |
2021 | 1 | 12 | 209 | 101 | 323 |
2022 | 7 | 261 | 53 | 82 | 403 |
Year | Sept | Oct | Nov | Dec | Total |
---|---|---|---|---|---|
1967 | 1519 | 1091 | 607 | 205 | 3422 |
1968 | 274 | 277 | 137 | 70 | 758 |
1969 | 1320 | 1177 | 789 | 402 | 3688 |
1970 | 366 | 254 | 170 | 66 | 856 |
1971 | 351 | 473 | 380 | 255 | 1459 |
1972 | 140 | 56 | 109 | 30 | 335 |
1973 | 599 | 193 | 211 | 82 | 1085 |
1974 | |||||
1975 | 1240 | 587 | 486 | 178 | 2491 |
1976 | 95 | 69 | 102 | 80 | 346 |
1977 | 126 | 147 | 233 | 130 | 636 |
1978 | 762 | 1060 | 321 | 221 | 2364 |
1979 | |||||
1980 | 1295 | 1697 | 523 | 401 | 3916 |
1981 | 286 | 522 | 349 | 277 | 1434 |
1982 | 2245 | 1609 | 1325 | 210 | 5389 |
1983 | 962 | 852 | 958 | 159 | 2931 |
1984 | 292 | 172 | 267 | 86 | 817 |
1985 | 316 | 332 | 564 | 386 | 1598 |
1986 | 694 | 567 | 313 | 286 | 1860 |
1987 | 261 | 292 | 222 | 124 | 899 |
1988 | 805 | 310 | 300 | 135 | 1550 |
1989 | 569 | 339 | 592 | 378 | 1878 |
1990 | 1493 | 947 | 1369 | 507 | 4316 |
1991 | 1076 | 779 | 872 | 260 | 2987 |
1992 | 755 | 530 | 463 | 266 | 2014 |
1993 | 1972 | 1567 | 908 | 710 | 5157 |
1994 | 439 | 387 | 391 | 117 | 1334 |
1995 | 3246 | 2220 | 791 | 555 | 6812 |
1996 | 1756 | 1072 | 935 | 523 | 4286 |
1997 | 265 | 565 | 639 | 1125 | 2594 |
1998 | 1318 | 2093 | 515 | 214 | 4140 |
1999 | 346 | 155 | 145 | 69 | 715 |
2000 | 253 | 326 | 126 | 59 | 764 |
2001 | 338 | 239 | 110 | 78 | 765 |
2002 | 372 | 832 | 334 | 382 | 1920 |
2003 | 3345 | 2947 | 1279 | 1789 | 9360 |
2004 | 680 | 83 | 78 | 106 | 947 |
2005 | 826 | 552 | 177 | 189 | 1744 |
2006 | 1119 | 142 | 646 | 406 | 2313 |
2007 | 123 | 257 | 116 | 57 | 553 |
2008 | 14 | 25 | 19 | 213 | 271 |
2009 | 81 | 75 | 252 | 216 | 624 |
2010 | 130 | 54 | 114 | 385 | 683 |
2011 | 413 | 204 | 142 | 135 | 894 |
2012 | 135 | 141 | 34 | 105 | 415 |
2013 | 74 | 61 | 86 | 88 | 309 |
2014 | 46 | 17 | 72 | 143 | 278 |
2015 | 6 | 12 | 22 | 39 | 79 |
2016 | 61 | 67 | 117 | 68 | 313 |
2017 | 434 | 451 | 1870 | 331 | 3086 |
2018 | 85 | 136 | 222 | 621 | 1064 |
2019 | 568 | 261 | 618 | 508 | 1955 |
2020 | 202 | 97 | 330 | 469 | 1098 |
2021 | 24 | 103 | 164 | 107 | 398 |
2022 | 110 | 155 | 198 | 235 | 698 |
Year | Sept | Oct | Nov | Dec | Total |
---|---|---|---|---|---|
1967 | 43 | 10 | 3 | 9 | 65 |
1968 | 6 | 7 | 3 | 2 | 18 |
1969 | 7 | 11 | 7 | 3 | 28 |
1970 | 13 | 0 | 2 | 2 | 17 |
1971 | 4 | 5 | 8 | 1 | 18 |
1972 | 3 | 0 | 1 | 9 | 13 |
1973 | 2 | 0 | 2 | 0 | 4 |
1974 | |||||
1975 | 2 | 1 | 0 | 1 | 4 |
1976 | 0 | 0 | 1 | 1 | 2 |
1977 | 0 | 0 | 0 | 0 | 0 |
1978 | 14 | 16 | 4 | 3 | 37 |
1979 | |||||
1980 | 11 | 4 | 1 | 0 | 16 |
1981 | 9 | 3 | 3 | 3 | 18 |
1982 | 76 | 20 | 12 | 11 | 119 |
1983 | 54 | 26 | 63 | 11 | 154 |
1984 | 10 | 1 | 4 | 1 | 16 |
1985 | 3 | 4 | 0 | 8 | 15 |
1986 | 14 | 25 | 8 | 11 | 58 |
1987 | 10 | 3 | 4 | 12 | 29 |
1988 | 3 | 4 | 2 | 0 | 9 |
1989 | 3 | 1 | 0 | 0 | 4 |
1990 | 5 | 2 | 1 | 0 | 8 |
1991 | 10 | 2 | 6 | 0 | 18 |
1992 | 2 | 0 | 1 | 0 | 3 |
1993 | 4 | 3 | 1 | 2 | 10 |
1994 | 0 | 1 | 0 | 2 | 3 |
1995 | 43 | 27 | 5 | 1 | 76 |
1996 | 13 | 0 | 0 | 9 | 22 |
1997 | 1 | 0 | 0 | 0 | 1 |
1998 | 127 | 92 | 45 | 17 | 281 |
1999 | 24 | 3 | 12 | 0 | 39 |
2000 | 0 | 4 | 3 | 1 | 8 |
2001 | 10 | 2 | 0 | 15 | 27 |
2002 | 0 | 0 | 1 | 0 | 1 |
2003 | 4 | 5 | 0 | 0 | 9 |
2004 | 1 | 2 | 1 | 0 | 4 |
2005 | 5 | 0 | 0 | 0 | 5 |
2006 | 1 | 0 | 3 | 0 | 4 |
2007 | 1 | 0 | 0 | 0 | 1 |
2008 | 0 | 0 | 0 | 0 | 0 |
2009 | 0 | 0 | 0 | 1 | 1 |
2010 | 0 | 0 | 0 | 0 | 0 |
2011 | 15 | 0 | 0 | 0 | 15 |
2012 | 0 | 0 | 0 | 1 | 1 |
2013 | 0 | 0 | 0 | 1 | 1 |
2014 | 0 | 0 | 0 | 1 | 1 |
2015 | 0 | 0 | 0 | 0 | 0 |
2016 | 0 | 0 | 0 | 0 | 0 |
2017 | 0 | 0 | 0 | 1 | 1 |
2018 | 0 | 0 | 0 | 0 | 0 |
2019 | 0 | 0 | 0 | 0 | 0 |
2020 | 0 | 0 | 0 | 0 | 0 |
2021 | 0 | 0 | 0 | 0 | 0 |
2022 | 0 | 0 | 0 | 0 | 0 |
Year | Sept | Oct | Nov | Dec | Total |
---|---|---|---|---|---|
1967 | 6810 | 3640 | 928 | 1357 | 12735 |
1968 | 1631 | 1570 | 1618 | 614 | 5433 |
1969 | 5915 | 1146 | 828 | 509 | 8398 |
1970 | 1596 | 820 | 786 | 861 | 4063 |
1971 | 1064 | 3473 | 1759 | 610 | 6906 |
1972 | 1527 | 1858 | 1106 | 622 | 5113 |
1973 | 1043 | 46 | 113 | 30 | 1232 |
1974 | |||||
1975 | 292 | 24 | 267 | 135 | 718 |
1976 | 1585 | 421 | 323 | 628 | 2957 |
1977 | 2703 | 2847 | 2897 | 569 | 9016 |
1978 | 984 | 481 | 149 | 485 | 2099 |
1979 | |||||
1980 | 1243 | 4023 | 1472 | 541 | 7279 |
1981 | 1164 | 3428 | 1823 | 259 | 6674 |
1982 | 304 | 375 | 1197 | 225 | 2101 |
1983 | 583 | 587 | 653 | 265 | 2088 |
1984 | 346 | 113 | 278 | 20 | 757 |
1985 | 278 | 258 | 60 | 225 | 821 |
1986 | 742 | 342 | 1657 | 88 | 2829 |
1987 | 891 | 72 | 1984 | 528 | 3475 |
1988 | 409 | 287 | 1555 | 158 | 2409 |
1989 | 1808 | 564 | 4209 | 316 | 6897 |
1990 | 405 | 898 | 1710 | 2846 | 5859 |
1991 | 631 | 420 | 1399 | 866 | 3316 |
1992 | 742 | 1054 | 371 | 791 | 2958 |
1993 | 1521 | 2537 | 1927 | 693 | 6678 |
1994 | 331 | 819 | 836 | 319 | 2305 |
1995 | 1631 | 592 | 730 | 384 | 3337 |
1996 | 146 | 1150 | 934 | 2528 | 4758 |
1997 | 797 | 3543 | 6140 | 4787 | 15267 |
1998 | 1922 | 2070 | 959 | 797 | 5748 |
1999 | 2670 | 772 | 2392 | 1693 | 7527 |
2000 | 68 | 1879 | 1218 | 9812 | 12977 |
2001 | 4382 | 1616 | 1407 | 6996 | 14401 |
2002 | 137 | 1024 | 253 | 317 | 1731 |
2003 | 748 | 339 | 380 | 497 | 1964 |
2004 | 610 | 179 | 330 | 182 | 1301 |
2005 | 287 | 1141 | 1009 | 428 | 2865 |
2006 | 1852 | 140 | 121 | 112 | 2225 |
2007 | 80 | 130 | 44 | 2923 | 3177 |
2008 | 59 | 293 | 66 | 32 | 450 |
2009 | 2 | 8 | 13 | 20 | 43 |
2010 | 37 | 36 | 3 | 44 | 120 |
2011 | 67 | 20 | 52 | 89 | 228 |
2012 | 5 | 3 | 11 | 22 | 41 |
2013 | 9 | 61 | 39 | 168 | 277 |
2014 | 18 | 1 | 175 | 88 | 282 |
2015 | 194 | 82 | 277 | 253 | 806 |
2016 | 114 | 50 | 252 | 244 | 660 |
2017 | 12 | 72 | 84 | 123 | 291 |
2018 | 24 | 84 | 33 | 57 | 198 |
2019 | 43 | 17 | 251 | 32 | 343 |
2020 | 43 | 5 | 522 | 65 | 635 |
2021 | 11 | 28 | 85 | 97 | 221 |
2022 | 7 | 39 | 73 | 138 | 257 |