• Call for Social Sciences Papers
  • Sign-up for PNAS eTOC Alerts

Benefits and risks of diversification for individual fishers

  1. Benjamin C. Williamsc,d
  1. aSchool of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195;
  2. bConservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanographic and Atmospheric Administration, Seattle, WA 98112;
  3. cCollege of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, AK, 99801;
  4. dDivision of Commercial Fisheries, Alaska Department of Fish and Game, Juneau, AK 99811;
  5. eAlaska Fisheries Science Center, National Marine Fisheries Service, National Oceanographic and Atmospheric Administration, Seattle, WA, 98115;
  6. fAuke Bay Laboratories, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanographic and Atmospheric Administration, Juneau, AK 99801
  1. Edited by Hugh P. Possingham, University of Queensland, St. Lucia, QLD, Australia, and approved August 4, 2017 (received for review March 2, 2017)


Individuals who rely on natural resources for their livelihoods, such as fishers, farmers, and forestry workers, face high levels of income variability. For fishers, catching multiple species has been shown to reduce revenue variability at large scales (vessels and communities), but the individual-level consequences of maintaining catch diversity are unknown. Our work demonstrates that individuals in fisheries targeting a diversity of species and individuals who participate in multiple fisheries buffer income variability compared with less diverse individuals. However, large adjustments in diversification strategies from year to year are risky and usually increase revenue variability. The most effective option to reduce revenue variability via diversification—purchasing additional permits—is also expensive, often limited by regulations, and therefore unavailable to many.


Individuals relying on natural resource extraction for their livelihood face high income variability driven by a mix of environmental, biological, management, and economic factors. Key to managing these industries is identifying how regulatory actions and individual behavior affect income variability, financial risk, and, by extension, the economic stability and the sustainable use of natural resources. In commercial fisheries, communities and vessels fishing a greater diversity of species have less revenue variability than those fishing fewer species. However, it is unclear whether these benefits extend to the actions of individual fishers and how year-to-year changes in diversification affect revenue and revenue variability. Here, we evaluate two axes by which fishers in Alaska can diversify fishing activities. We show that, despite increasing specialization over the last 30 years, fishing a set of permits with higher species diversity reduces individual revenue variability, and fishing an additional permit is associated with higher revenue and lower variability. However, increasing species diversity within the constraints of existing permits has a fishery-dependent effect on revenue and is usually (87% probability) associated with increased revenue uncertainty the following year. Our results demonstrate that the most effective option for individuals to decrease revenue variability is to participate in additional or more diverse fisheries. However, this option is expensive, often limited by regulations such as catch share programs, and consequently unavailable to many individuals. With increasing climatic variability, it will be particularly important that individuals relying on natural resources for their livelihood have effective strategies to reduce financial risk.


  • ?1Present address: Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, V6T 6N7, Canada.

  • ?2To whom correspondence should be addressed. Email: sean.anderson{at}dfo-mpo.gc.ca.

Freely available online through the PNAS open access option.

Online Impact

                                    1. 99132880 2018-01-23
                                    2. 802899879 2018-01-23
                                    3. 295573878 2018-01-23
                                    4. 352668877 2018-01-23
                                    5. 984633876 2018-01-23
                                    6. 545928875 2018-01-23
                                    7. 976569874 2018-01-23
                                    8. 871324873 2018-01-23
                                    9. 263462872 2018-01-23
                                    10. 577161871 2018-01-23
                                    11. 255603870 2018-01-23
                                    12. 117346869 2018-01-23
                                    13. 90982868 2018-01-23
                                    14. 663415867 2018-01-23
                                    15. 793874866 2018-01-23
                                    16. 843582865 2018-01-23
                                    17. 864971864 2018-01-22
                                    18. 258841863 2018-01-22
                                    19. 957295862 2018-01-22
                                    20. 553518861 2018-01-22