Pathways to sustaining tuna-dependent Pacific Island economies during climate change

Abstract

Climate-driven redistribution of tuna threatens to disrupt the economies of Pacific Small Island Developing States (SIDS) and sustainable management of the world’s largest tuna fishery. Here we show that by 2050, under a high greenhouse gas emissions scenario (RCP 8.5), the total biomass of three tuna species in the waters of ten Pacific SIDS could decline by an average of 13% (range = −5% to −20%) due to a greater proportion of fish occurring in the high seas. The potential implications for Pacific Island economies in 2050 include an average decline in purse-seine catch of 20% (range = −10% to −30%), an average annual loss in regional tuna-fishing access fees of US$90 million (range = −US$40 million to –US$140 million) and reductions in government revenue of up to 13% (range = −8% to −17%) for individual Pacific SIDS. Redistribution of tuna under a lower-emissions scenario (RCP 4.5) is projected to reduce the purse-seine catch from the waters of Pacific SIDS by an average of only 3% (range = −12% to +9%), indicating that even greater reductions in greenhouse gas emissions, in line with the Paris Agreement, would provide a pathway to sustainability for tuna-dependent Pacific Island economies. An additional pathway involves Pacific SIDS negotiating within the regional fisheries management organization to maintain the present-day benefits they receive from tuna, regardless of the effects of climate change on the distribution of the fish.

Clustering of disaggregated fisheries data reveals functional longline fleets across the Pacific

“…120,121 For transboundary fisheries in the Pacific Ocean, fleet-disaggregated analyses could be used to (1) address the differential effects of time/area closures and catch quotas, (2) analyze the competition for space among sectors (i.e., large-scale versus small-scale, longline versus purse-seine) and emerging ocean users (i.e., offshore wind farms, aquaculture operations, and deep-sea mining claims), (3) study the socioeconomic attributes and/or environmental associations of different fishing livelihood strategies, (4) estimate bycatch and non-target species interactions, and (5) audit self-reported logbook records. Given the degree to which concerns regarding the relative distribution of costs and benefits continue to impede the adoption of pelagic longline management and conservations measures 77 and recent research regarding the asymmetrical impacts of climate change on regional fishery landings and revenue, 9 we suggest such applications are particularly salient for transboundary fisheries across the Pacific.…”

“…Enduring knowledge gaps surrounding the nature and extent of regional resource extraction have contributed to ongoing biodiversity loss 7 while functioning to undermine the development of sustainable harvest strategies and the provision of social and economic benefits. 8 As new threats and stressors emerge alongside accelerating global environmental and socioeconomic change, 9 calls for increased coordination, cooperation, and transparency across the sector have intensified, and the need for equitable and comprehensive ecosystem-based resource management has grown increasingly urgent. 10,11 Although high-volume purse-seine fisheries comprise the vast majority of large pelagic fisheries landings across the Pacific, pelagic longline fisheries represent a substantial proportion of total catch value (30% in the Western Pacific in 2019 12 ) while exerting significant top-down pressure on open-ocean ecosystems across the basin.…”

Seafood in Food Security: A Call for Bridging the Terrestrial-Aquatic Divide

“…For Pacific Island countries and territories, for example, where subsistence fishing provides a key source of dietary protein, forecasts predict that even well-managed fisheries will struggle to meet demand in 2030 (Bell et al, 2009). In this region, redistribution of fish due to climate change poses a serious threat to food security, one which may require policy intervention and negotiations to ensure long-term resource conservation (Bell et al, 2021). Such region-specific research is needed to ensure local seafood system sustainability, with knowledge sharing across regions allowing best practice to spread rapidly and underpin global sustainability.…”

AMPLE: An R package for capacity building on fisheries harvest strategies

“…The four main target species, skipjack, yellowfin, bigeye and albacore, are caught by a diverse range of fleets and fishing methods. For many countries in the WCPO, tuna fisheries are crucial for their economies, livelihoods and culture [ 8 – 11 ]. However, tuna stocks will only be a dependable and renewable resource if they are managed responsibly.…”