Monterey Bay Aquarium Research Institute

The early life history and fishery of the California market squid, Loligo opalescens


Louis Zeidberg, Ph.D.

Wednesday, May 19, 2004
Pacific Forum – 3:00 p.m.


The severe decline in the California commercial fishery for Loligo opalescens following the 1997 El Niño lead to industry-sponsored research. Thus we examined egg beds in Monterey Bay, paralarvae distribution in the Southern California Bight, video of juveniles from MBARI, and reviewed fishery landings data for 1981–2003. Observations of egg beds led to new theories of spawning behaviors and confirmed egg predators. As sample sites approached shore, paralarvae abundance increased dramatically. Furthermore, ageing revealed that the paralarvae were entrained for weeks within 3 kilometers of shore. These hatchlings exhibited a 15 meter vertical diel migration. Juveniles were filmed in-situ in Monterey Bay with an ROV and were captured with a trawl in Santa Monica Bay for allometry measurements. Squid fishery landings decreased substantially following large El-Niño events, 1982–1983 and 1997–1998.We created a regression of catch per unit effort (CPUE) from a paralarvae density index (PDI) for management applications.

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