Squid: An Ecosystem Perspective

By Sean Hastings

The harvest of market squid within the Channel Islands National Marine Sanctuary has reached epic proportions in the last five years. In 1996, the squid fishery was the top fishery in volume and economic value in California, with a majority of the harvest centered in the northern Channel Islands (see article on page 7).

Squid play a vital role in the California Current ecosystem, serving as a major link in the food chain as both predator and prey. A variety of seabirds, including sooty and pink footed shearwaters, western gulls, and common murres, dive for squid. A majority of the marine mammals in the Sanctuary, including California sea lions, elephant seals and Risso's dolphins, depend on squid as well. Several fish species, including many that support other fisheries (like yellowfin tuna and halibut), depend on squid as a food resource. Squid are considered voracious predators, preying on copepods and small fish species.

A shift in squid biomasseither due to harvesting, or to oceanographic conditions, like the upcoming El Niñocan send ripples throughout the ecosystem. Resource management agencies, like CINMS and the Department of Fish and Game, are tasked with balancing multiple, often conflicting goals of protecting all species and ensuring a sustainable harvest of targeted species. Effective management requires considering the ecological impacts of harvesting on the entire ecosystem.

Fishery management is not about managing fish, but about managing people. We cannot change El Niño events, but we can work to understand the effects of El Niño on squid biomass as well as the effects of other oceanographic and biological conditions on squid. With a greater understanding of these pieces of nature's puzzle, we can adjust our management and harvest strategies to reflect changes in the environment.


Fishermen supervise the pumping of squid   (©1996 Tom Campbell)

Squid serve as an important protein source to millions of people in the Mediterranean countries, Asia and the United States. The goal, then, should be to harvest squid sustainably so that people and enough squid to fill their niche there are enough squid for in the environment in perpetuity. Currently a variety of Federal and State bills and management options, including California State Senate Bill 364 (the Sher Bill) are being considered to accomplish this goal. For the latest developments regarding state squid legislation, visit the World Wide Web at http://www.leginfo.ca.gov/. Then look under "Bill Information" and enter the number of the bill, or the word "squid."

Unlike many fisheries, squid is considered a relatively "clean" fishery with very little bycatch reported in the catch. While this makes one management issue less troublesome, there remain several questions about other ecological impacts from fishing. For example, do the light boats that turn "night into day" to draw squid to the surface disturb nesting seabirds? Does the harvest of squid (90,000 tons in 1996) have an impact on the squid population or the species that depend on squid?

The fact is that researchers and resource managers simply don't know how much squid is out there and how the population fluctuates. Several research institutions and researchers, from Scripps Institute in San Diego to Moss Landing in Monterey, are beginning to research squid popu-lation dynamics and the squid's role in the California Current ecosystem. Resource managers, fishermen, processors and researchers are coming to the table to discuss what is known, what is unknown and how to manage this burgeoning fishery. See "Things To Do" on page 12 of this issue for details of the upcoming Squid Symposium in October.

Sean Hastings is Research Program Specialist at CINMS.

Purse seiners at work setting their nets.  (©1997 D.B.Pleschner)