| SS9.01 Ecosystem Science Practiced in an Urbanized Estuary: South San Francisco Bay |
| Schafer, K, L, Aquamarine Research, Mountain View, USA, kateschafer@earthlink.net |
| |
| LONG TERM OBSERVATIONS OF FISH POPULATIONS IN SOUTH SAN FRANCISCO BAY |
 |
| We report on a study comparing the changes in fish populations in South San Francisco Bay over a thirty-year period. The analyses are based on 2,561 otter trawls completed between February 1973 and June 1982 and an additional 3,999 trawls completed between October 1992 and December of 2001. Striking differences in fish abundances were seen between the two time periods, although there was no general trend across all species. All of the nine observed species of surfperches (Family Embiotocidae) have declined dramatically during the period of this study, and several species have not been collected for more than ten years. English sole (Parophrys vetulus) populations have also shown a significant decline between the two time periods. At the same time, populations of species with similar habitat preferences, including speckled sanddabs (Citharichthys sordidus) and Pacific sanddabs (Citharichthys stigmaeus), have increased or remained stable during the same time period. California halibut (Paralichthys californicus) populations have increased, and seem to be heavily influenced by offshore sea surface temperatures. |
|
|