Biological characteristics of the catch from the 1990-91 Pacific Herring, Clupea pallasi, roe fishery in California
1991
Spratt, Jerome D.
The Tomales-Bodega Bay catch during the past two seasonshas been from the northern part of Bodega Bay, due to theclosure of the Tomales Bay fishery.In the Tomales-Bodega Bay area, 4-, 5-, and 6-yr-old herringClupea pallasi, comprised 79% by number of the 1990-91season's gill net catch.The number of 4-yr olds (1987 year class) increased to 21%of the gill net catch. Four-yr olds are an indicator of recruitment strength into the gill net fishery.Average length of herring in the Tomales-Bodega Bay areagill net catch decreased due to a shift to younger herringin the catch, as well as, poor growth characteristics during1990. Herring age and size data obtained from Tomales Bay with avariable mesh research gill net were similar to data from San Francisco Bay obtained with the same net. All age classes were taken and herring ranged in length from 148 mm to 226 mm.In San Francisco Bay, the age composition of the gill netcatch was also primarily 4-, 5-, and 6-yr-old herring, whichcomprised 79% of the catch. In the round haul fishery 2- and3-yr-old herring dominated, comprising 72% of the catch.The average length of herring in the San Francisco Bay gillnet and round haul catches decreased. Both are the lowestrecorded average lengths by the respective gear types exceptfor the 1983-84 El Nino season.Observed poor growth characteristics this season are attributed to reduced upwelling off central California in 1990. (26pp.)
显示更多 [+] 显示较少 [-]