UC Santa Cruz and federal fisheries lab join forces in Center for Stock Assessment Research

Concerns about the sustainability of many West Coast fish populations have led to increasingly tight restrictions on the fishing industry, angering some fishers whose livelihoods are at stake and highlighting the importance of accurate assessments of commercial fish stocks. To help meet the demand for fishery scientists with expertise in the quantitative assessment of fish populations, the University of California, Santa Cruz, and the National Marine Fisheries Service (NMFS) Santa Cruz Laboratory have formed a new partnership called the Center for Stock Assessment Research (CSTAR).

CSTAR is funded by NMFS to support UCSC students (both undergraduates and graduate students) and postdoctoral researchers working in the areas of quantitative fish population dynamics and fishery stock assessment. The program is part of a nationwide effort by the National Oceanic and Atmospheric Administration (NOAA), which oversees the fisheries service, to address the need for more scientists with this kind of training, said Churchill Grimes, director of the NMFS Santa Cruz Laboratory.

In addition to training scientists, CSTAR supports research on advanced stock assessment methods, said Marc Mangel, a professor of applied math and statistics at UCSC, who heads the CSTAR program together with NMFS fishery biologist Alec MacCall.

"We need a better understanding of the dynamics of fish populations to do a better job of managing them," Mangel said. "NMFS is charged with doing the analyses to provide a scientific basis for managing fisheries, and our job in CSTAR is to train people who can do those analyses and to develop new methods that can be applied to the problems of fisheries management."

The NMFS Santa Cruz Lab is responsible for assessments of West Coast salmon and groundfish populations. Groundfish include flatfish such as halibut, roundfish such as lingcod, many different species of rockfish (usually marketed as red snapper), bottom-dwelling sharks and skates, and several other species. As part of their training, UCSC students and postdocs in the CSTAR program work with NMFS scientists on ongoing stock assessments.

"In doing stock assessments, the idea is to bring in as many kinds of information as you can to assess the health of the stock, including numbers of fish, age distribution, sex distribution, and size distribution, because all of those factors affect the population dynamics and determine how the stock will respond to fishing pressure," Mangel said.

The Pacific Fishery Management Council has imposed progressively tighter restrictions on the groundfish fishery over the past five years to allow certain populations to recover from overfishing. These restrictions are having serious economic impacts, which might have been avoided if scientists had understood the fishery 20 years ago as well as they do now, MacCall said.

"We are facing a crisis here on the West Coast that is comparable to the collapse of the sardine fishery in the 1940s and '50s," MacCall said. "The only hope for avoiding this kind of disaster in the future is to have really talented people on the job keeping track of things. It all hinges on our ability to determine how many fish are out there and how much is safe to catch on a sustainable basis."

Many species of groundfish are very long-lived and slow to reproduce, which means that rebuilding their populations will take decades, and in some cases centuries. The estimated recovery time for yelloweye rockfish in northern California, for example, is 208 years.

"Chances are we won't see a healthy groundfish fishery on the West Coast in our lifetimes," MacCall said. "Some of these species live up to 150 years, so their whole life strategy as a fish is to be in it for the long haul. Unfortunately, it took us 20 years to finally be able to do the analyses to say, oops, we've gone too far. That kind of analysis is what CSTAR is now training people to do."

Nine UCSC students and postdocs are currently members of CSTAR, including Michael Bonsall, a visiting research fellow studying speciation and the evolution of longevity in rockfish; Teresa Ish, a graduate student in ocean sciences doing research on the squid fishery, California's largest fishery in terms of volume landed and commercial value; Andi Stephens, a graduate student in ocean sciences looking at the ecological effects of Atlantic salmon that escape from aquaculture ("fish farms") on the West Coast; and Kate Siegfried, an environmental studies graduate student studying the life histories of sharks.

CSTAR gives students a rare opportunity to tackle real-world problems in an academic setting, Mangel said.

"I think the current generation of students, more than any generation that has preceded them, really want to do useful things--they want to solve problems," Mangel said. "With CSTAR, they have the ability to work on important problems at an academically rigorous level, so they can leave here with the training they need to make the kind of contribution they want to make."


Editor's note: Reporters may contact Mangel at (831) 234-2970 or msmangel@ams.ucsc.edu, and MacCall at (831) 420-3950 or alec.maccall@noaa.gov.