Rockfish Recruitment and Ecosystem Assessment Cruise Concludes

The SWFSC Fisheries Ecology Division’s Rockfish Recruitment and Ecosystem Assessment Survey concluded on June 12, 2010, following approximately 40 days at sea on the chartered research trawler, the F/V Frosti. A total of 136 midwater trawls and 235 CTD casts, as well as zooplankton samples, seabird and mammal observations, and continuous underway data collections were conducted.

The survey targets pelagic juvenile rockfish for fisheries oceanography studies and for developing indices of year class strength for stock assessments. Preliminary results indicate that rockfish recruitment trends in 2009 and 2010 were of increasing abundance following low productivity in the preceding four years, although this abundance is close to the long term mean for this assemblage. Other young of year groundfish (such as Pacific hake, lingcod and several flatfish species) were also encountered at high levels, as were market squid and euphausiids, while coastal pelagic species abundances were low, likely as a result of reduced availability and an offshore distribution. Humboldt squid, encountered regularly since 2004, were not encountered in either trawl or jigging operations this year. As with the 2009 data, results from this year continue to represent a return to cool, high productivity conditions similar to the 1999 to 2003 period for many groups, while others are at moderate levels that approximate long term mean conditions.

(June 25, 2010)