POD! Fish- DFG Summer Townet Survey Juvenile fish sampling 1959-2006

Since 1959, this survey has developed indices for the abundance of young striped bass when the average size is 38 mm by sampling 31 stations from San Pablo Bay through the Delta. The original purpose was to predict recruitment to the adult stock but the index has proven valuable in gauging the environmental health of the estuary. Young striped bass abundance is primarily a function of Delta outflow, Delta water exports and egg production. Abundance indices for other species have also revealed important trends. For example, the index for delta smelt was useful in determining its status as a threatened species. This survey is mandated by the 1995 USFWS Biological Opinion (BO) for delta smelt on the operation of the SWP and CVP.

自1959年起，本调查通过对圣巴勃罗湾（San Pablo Bay）至三角洲（Delta）区域的31个采样站位进行采样，构建了平均体长38毫米的幼条纹狼鲈（striped bass）的丰度指数。该调查最初的目的是预测成鱼种群的补充量，但后续证明该指数在评估河口生态系统健康状况方面极具应用价值。幼条纹狼鲈的丰度主要由三角洲径流量、三角洲外调水量以及产卵量决定。其他物种的丰度指数也揭示了重要的种群动态趋势。例如，三角洲胡瓜鱼（delta smelt）的丰度指数曾用于确定其被列为受威胁物种的保护等级。本调查是1995年美国鱼类及野生动物管理局（USFWS）针对三角洲胡瓜鱼（delta smelt）发布的、针对州水资源工程（SWP）与中央河谷工程（CVP）运行方案的生物意见书（BO）所强制要求开展的。