Where marine predators and fishers come into contact, conflict follows. Across the world, conservation has been helping pinnipeds (seals, sea lions, and walruses) recover after being systematically hunted and culled. In parallel, this recovery has revived their clash with fisheries – a crucial livelihood for coastal communities around the world.
New research has revealed that pinnipeds and fisheries interact frequently, and the losses are significant; a third of all fishing days have interactions with pinnipeds, and 13.8% of catch is lost. However, these losses aren’t distributed evenly; small-scale fisheries are almost three times as likely to have negative interactions and lose four times more catch to pinnipeds than large-scale fisheries. Senior author Dr Katrina Davis said:
“The conflict threatens pinniped population recovery, but also can impose really harmful impacts on fisheries. The variation in impacts experienced by small and large-scale fisheries explains why our results show more frequent interactions but lower catch loss than we might expect – the often severe losses incurred by small-scale fisheries are partly masked by the relatively smaller losses incurred by large-scale fisheries.”
Fisheries using nets see more interactions and a higher proportion of catch lost. Net fisheries interact with pinnipeds on 41.2% of fishing days and lose 17.0% of their catch, in contrast to just 15.1% of fishing days and 3.44% of catch lost in line fisheries. Small-scale fisheries using nets are consequently the most likely to both interact and lose out.
It’s critical to balance ecological, economic, and social outcomes in this conflict. The researchers have mapped potential hot-spots for interactions to help guide management efforts – these hot spots are areas with high fishing effort, the presence of pinnipeds, and proximity to a coast. This information can help to target conflict mitigation schemes, including trials of acoustic deterrent devices and other technologies, as well as monitoring and compensation programs.
The poorest sectors of society bear much of the burden of human-wildlife conflict, and the importance of engaging with small-scale fisheries in this context is becoming ever clearer. The Food and Agriculture Organization of the United Nations declared 2022 the ‘international year of artisanal fisheries and aquaculture’, citing the small-scale fishing industry as ‘small in scale, big in value’ for the achievement of sustainable development goals. Katrina added:
“Pinniped population recovery is absolutely a conservation success story. However, we need to be conscious of the impact of this success on fishing industries and look for solutions that protect recovering pinniped species without imposing large costs on fisheries. The livelihoods of this important natural resource sector must be protected, and strategies such as compensation can go a long way.”
The next steps in this area of research are to review the success of mitigation technologies, including acoustic deterrents, to understand what has been most effective in different settings — and the attractiveness or practicality of these technologies for fishers. The researchers are also developing bioeconomic models to explain how depredation behaviours (e.g., consumption of fisheries catch by seals) spread through seal populations and how fishery incomes are impacted by this spread.
To read more about this research, published in Nature Communications, visit: https://doi.org/10.1038/s41467-024-51298-6
