SAN FRANCISCO, Sept. 24 (Xinhua) -- A team of researchers in the United States has found that individuals who diversified their fish catch had much less income variability than people who specialized by fishing one species or obtaining a single type of fishing permit.
Being the first to track the effect of fishing practices on individuals, rather than fishing fleets or communities, the researchers evaluated income volatility among those employed in an area with some of the largest, most valuable fisheries in the world - the waters surrounding the state of Alaska.
Based on analysis of nearly 30 years of revenue and permitting records for individuals fishing in Alaskan waters and on tracking how their fishing choices, in terms of permits purchased and species caught, influenced their year-to-year income volatility, the findings were published in the latest issue of the Proceedings of the National Academy of Sciences, or PNAS.
The researchers discovered that individual fishers who specialized by purchasing one permit had greater year-to-year variability in income compared to fishers who purchased multiple permits. The magnitude of the income variability depended on the species that the permit covered.
In the United States, both the federal government and state agencies manage fisheries through a system of permits and quotas that individuals can purchase. Quota systems allow permit holders to purchase shares, or a fraction of the total allowed catch. And permits vary widely by the number of species they allow the holder to catch, when they can catch and the fishing techniques allowed.
In Alaska, permits regulate who can fish for salmon, sea cucumbers and sea urchins, for example. In the mid-1990s, regulators began to use individual quota systems to manage certain species in waters surrounding the state, such as halibut, sablefish and king crab.
"Previous work has shown that individuals who fish commercially have higher income variability than farmers," lead author Sean Anderson, who conducted the research as a postdoctoral researcher in the University of Washington (UW) School of Aquatic and Fishery Sciences, said in a news release. "Our analysis showed that fishers holding single permits expose themselves to exceptional risk of high year-to-year income variability."
Most individual fishers, 70 to 90 percent, held one permit over the study period, perhaps because diversifying is no simple task. Permits may cost thousands or hundreds of thousands of U.S. dollars, depending on the species, location, scope and fishing method, and the cost of these permits has increased over time. Other barriers, such as caps on the number of permits and the costs of purchasing additional gear for multiple species, may also make diversifying difficult.
The research was the joint work of researchers from UW, the U.S. National Oceanic and Atmospheric Administration (NOAA), the University of Alaska Fairbanks and the Alaska Department of Fish and Game.
"We do not know which factors - including fishing costs, natural forces, market demand and management policies - have made the majority of individual fishers specialize despite high income variability," acknowledged co-author Eric Ward, with NOAA's Northwest Fisheries Science Center. "Additional research may, in time, help scientists and policymakers come up with practices that can reduce income variability for fishers and keep fishery harvests sustainable."
