Diversifying fisheries portfolios stabilizes fishing communities

February 12, 2018

Cline TJ, DE Schindler, and R Hilborn. 2017. Fisheries portfolio diversification and turnover buffer Alaskan fishing communities from abrupt resource and market changes.  Nature Communications 8:14042.

In a nutshell
  • Many coastal fishing communities the world over focus their fishing efforts on a small number of target species without explicitly maintaining capacity to take advantage of other potential marine resources
  • Overreliance on a handful of select fisheries may increase the susceptibility of these communities to detrimental impacts resulting from abrupt shifts in natural and market conditions
  • Here, fishing-derived revenues were compared among coastal communities throughout Alaska over a 20-year period marked by sudden shifts in environmental and market conditions, with communities that engaged in a broader range of fisheries found to be more resilient to such changes than were communities in which fishing efforts were more narrowly targeted
  • Diversifying fisheries may therefore represent a means by which fishing-based communities can mitigate potential negative economic and social impacts associated with abrupt changes in natural and market conditions
Many fishing communities in coastal areas around the world have become increasingly dependent on a handful of often dynamic and variable marine resources for their economic livelihoods and subsistence, leaving them vulnerable to rapid and unexpected changes in environmental conditions and markets at local, regional, and even global scales. Moreover, the uncertainty associated with future climate change further heightens the economic risk of increasing specialization in these communities, as the geographical ranges and abundance of many marine species are expected to shift in response to warmer water temperatures, increasing acidification, altered water chemistry, and other physical and ecological changes.

Broadening the resource base of the local economy is one strategy that fishing communities could employ to overcome the limitations of overspecialization and improve both economic and social resilience, according to a recent analysis conducted by Tim Cline, a graduate student at the University of Washington’s School of Aquatic and Fishery Sciences, and his colleagues. Cline and his team compared average fishing revenues in 106 Alaskan coastal communities over a 20-year period encompassing the 10 years prior to and the 10 years following 1989, a time frame during which physical changes in the North Pacific Ocean transformed the ocean food web, and surging salmonid aquaculture production undercut the global market price of wild-caught salmon.

A dataset provided by the Alaska Commercial Fisheries Entry Commission containing several decades worth of information about the harvesting patterns of coastal fishing communities in Alaska enabled the researchers to assess the relative stability and resilience of those communities engaging in a wide variety of fisheries to those reliant on a narrower range of target species based on fluctuations in community fishing revenues. Cline et al.’s analysis indicated that although total annual revenues declined by as much as 50% in many fishing-dependent Alaskan communities, those exploiting a wider diversity of marine resources were buffered from the shocks of abrupt changes in environmental or market conditions to a much greater degree than those utilizing only a relatively small range of marine resources. Moreover, communities engaging in the highest levels of resource diversity were largely impervious to ecological and market variability, with some even benefiting, as those communities had the capacity to switch – at the community level if not the individual level – between fisheries depending on which were the most profitable at any given time, and to take advantage of new revenue streams, such as the then-emerging sushi market.

In light of these results, Cline and his coworkers concluded that, much like financial analysts who advise that shareholders spread their risk by investing across a range of assets, fishing-dependent communities worldwide should likewise be encouraged to adopt broader fisheries portfolios as a way to safeguard against the worst impacts of market volatility and changes in natural conditions. In addition, management agencies could develop policies that encourage flexibility in the resources harvested by fishing communities as marine ecosystems respond to ongoing global change.

Science Spotlight by Ken Ferguson