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As climate change raises the ocean’s temperature, some fish species are moving poleward to cooler waters. In the United States, as elsewhere, commercial fishers are trying to adapt. But as a new study of trawler communities along the US east coast documents, fishers’ efforts to adjust are being constrained by a regulatory environment that isn’t adapting with them.
The research, led by Eva Papaioannou, a marine ecologist with the GEOMAR Helmholtz Centre for Ocean Research Kiel in Germany, looked at trawl fishing communities in 10 ports from North Carolina to Maine, where rising water temperatures have been especially pronounced.
Papaioannou and her colleagues dug into government records and vessel trip reports, examining decades of data about vessel activity patterns, distributions of fish stocks, and fish landings. They compared two periods, 1996 to 2000 and 2011 to 2015, and confirmed that the fish these communities are primarily targeting, fluke and hake, had shifted northward by up to 200 kilometers.
The scientists also interviewed members of these communities to find out how they were responding to their changing fishing grounds. “Fishers are on the water every day, so they see these changes, and they’re incredibly adept at dealing with variability,” says Becca Selden, a biologist at Wellesley College in Massachusetts, and a study co-lead.
The team found that the majority of fishers remained in their traditional grounds, but switched to targeting different, more abundant species. “Most prior work assumed that there wouldn’t actually be species switching,” says Selden. “But this was one of the dominant strategies that we observed.” As the scientists wrote in their study, this desire for “spatial stability” of fishing grounds was both the preferred strategy among all fisher communities surveyed, but also the most sustainable practice for local fish stocks.
But switching species comes at a cost. According to the researchers, fishers need the flexibility to catch a variety of species—something that regulations often thwart. “The realities of what and where they fish are mediated by the regulatory framework,” says Papaioannou by email.
Federal and state management plans determine which species can be caught and which must be avoided, and these plans have grown more exacting over the years. Fishers can only harvest within the limits of the permits they purchase, and each species typically requires a separate permit. Harvesting diverse fish types then becomes expensive, and those who cannot bear the cost are constrained in what they catch.
“Multiple permits cost money,” says Elliott Hazen, an ecologist with the US National Oceanic and Atmospheric Administration’s Southwest Fisheries Science Center who was not involved in the research. “And that tends to favor larger fishing vessels. Smaller vessels are probably most at risk from losing access when species move.” Consequently, the researchers found that while many trawl operators were changing their fishing practices to new target species between the two time periods studied, catch diversity actually declined.
While those with smaller trawlers usually remained in their traditional grounds, the study found that those with larger vessels (over about 20 meters) would sometimes embark on longer voyages from their home ports to follow their target fish to new waters. This was rarely the fishers’ first choice, however. Such ventures are more expensive, potentially more hazardous, and keep fishers away from home for longer periods. Fishers, Papaioannou says, desire to fish their traditional grounds, where they possess a vast local knowledge. Their allegiance to their home port is key in shaping their responses to changes in the abundance and distribution of fish, she adds.
The study noted that regulations may be incentivizing these long voyages. Each port has a quota for a specific fish that is based on past harvest levels, with higher catch histories resulting in higher quotas. This can mean a ready market for landing catches—even if the species is no longer abundant in nearby waters. The scientists found that some captains have become itinerant in response to these incentives. Rather than returning to their home port to land their catch, they will travel to different ports along the coast where they can best exploit quota allocations.
Most management policies, Selden says, are based on the assumption that fish populations are in equilibrium. But when these populations change, quota allocations don’t change with them. “We’re pegging quotas to biomass,” she says, “but we’re not addressing any directional shifts.” This can benefit some ports but impair others, affecting the livelihoods of fishing industry service workers and fostering more transient fishing communities, according to the researchers.
Fishing regulations could be more responsive to shifting circumstances if management agencies were equipped with more timely data, says Selden. One source of such data might even be the fishing communities themselves. “The technology on these fishing boats is incredible,” says Selden. “Empowering them to collect their own data would help them trust it and to see how it integrates with other fishers into a bigger picture.”
Fishing communities are already adapting to the consequences of climate change. The researchers say that regulatory support for these communities must adapt, too. Policies to allow more flexible species harvesting closer to home ports would do a lot to make fishing safer, more effective, and more economical in a changing world.