Fisher Responses to Variability in the Bering Sea Pollock Fishery

Abstract

Pollock recruitment and biomass in the Bering Sea has fluctuated in concert with environmental changes since the early 2000s. As pollock spatial distributions, densities, and abundances varied, fishers have adjusted their fishing behavior. Utilizing ~30,000 trips made by Bering Sea pollock catcher vessels from 2003 – 2014, we found strong correlations between the distances that vessels traveled and both pollock survey abundance and bottom temperatures. During colder years when waters drove pollock populations north (during the summer B season) and closer to the edge of the Bering Sea shelf, many vessels traveled farther, following fish and maintaining high catch per unit effort (CPUE), despite low pollock abundance. The temperature and abundance relationships remain difficult to disentangle, however, as recent warm years have all occurred in concert with abundant pollock. Without low abundance warm years for comparison, it is difficult to project the impacts of warming. However, if warm waters yield predicted poor recruitment, then pollock may require more effort, even when closer to port. This increased effort (decreased CPUE) represents an additional cost to fishers because vessels use significantly more fuel while fishing than while transiting. Longer trips offer complicated trade-offs for fishers. The far-ranging trips overall had statistically similar net earnings as the shorter trips, suggesting that the higher CPUEs offset the costs, but many vessels are unable to profitably make these longer trips. As climate changes further and variability of pollock populations is predicted to increase, understanding the ability of different vessels to adapt is critical for efficient management.