Rethinking sustainability in seafood

Abstract

Sustainability is a common goal and catchphrase used in conjunction with seafood, but the metrics used to determine the level of sustainability are poorly defined. Although the conservation statuses of target or nontarget fish stocks associated with fisheries have been scrutinized, the relative climate impacts of different fisheries are often overlooked. Although an increasing body of research seeks to understand and mitigate the climate forcing associated with different fisheries, little effort has sought to integrate these disparate disciplines to examine the synergies and trade-offs between conservation efforts and efforts to reduce climate impacts. We quantified the climate forcing per unit of fish protein associated with several different U.S. tuna fishing fleets, among the most important capture fisheries by both volume and value. We found that skipjack tuna caught by purse seine, a gear type that is often associated with relatively high bycatch of nontarget species, results in lower climate forcing than all other sources of proteins examined with the exception of plants. Conversely, skipjack tuna caught by trolling, a gear type that is often associated with relatively low bycatch of nontarget species, generates higher climate forcing than most other protein sources with the exception of beef. Because there is a range of selectivity and climate forcing impacts associated with fishing gears, examining the trade-offs associated with bycatch and climate forcing provides an opportunity for broadening the discourse about the sustainability of seafood. A central goal of more sustainable seafood practices is to minimize environmental impacts, thus mitigation efforts—whether they target conservation, habitat preservation, or climate impacts—should consider the unintended consequences on fisheries conservation.

Benefits, concerns, and solutions of fishing for tunas with drifting fish aggregation devices

“…A number of recent studies using different data sources and numerical methods concur that PS fishing for tropical tunas (including dFAD sets) has a lower fuel use intensity (i.e., the ratio of biomass caught to fuel consumed) and overall carbon footprint compared to other non-PS fishing methods and most terrestrial forms of meat production (Basurko et al, 2022;Chassot et al, 2021;Mckuin et al, 2021;. found that "surrounding nets" fishing methods (including fishing for both small and large pelagics) had the lowest fuel use intensity of all industrial fishing methods included in their analysis.…”

“…The higher fuel consumption when using dFADs compared to FSC is likely explained by (i) the use of supply vessels (in some oceans); (ii) the larger vessel size (>80 m) of highly dFAD‐dependent purse seiners; and (iii) the larger spatial extent of the dFAD fishery (Chassot et al, 2021). Overall, fishing for large pelagics (including a variety of non‐PS gear types), had a carbon footprint per kilogram (kg) of catch comparable to that of pork, chicken and some forms of aquaculture; all of which are considerably lower than those of wild‐caught crustaceans and beef production (Mckuin et al, 2021). In particular, Mckuin et al (2021) found that, for skipjack catch, the climate forcing (which combines fuel use consumption and fuel‐specific global warming potentials) with highly selective gears like trolling is as much as 12 times higher than the skipjack caught with the less selective gear such as PS, and PS skipjack climate forcing is lower than all terrestrial and other fishery food sources.…”

Environmental performance of Cantabrian (Northern Spain) pelagic fisheries: Assessment of purse seine and minor art fleets under a life cycle approach

“…Worldwide studies on FUI are mainly concerned with species-specific fisheries. In this line there are different claims for tuna fisheries, with consumptions ranging from 0.28 to 0.77 using purse seiners (Avadí and Fréon, 2015;McKuin et al, 2021), to values of 0.95 when longline is used . In the case of other species, such as anchovy catches by purse seine, the use of diesel per FU is 0.34 (Laso et al, 2018b), somewhat higher than that recorded for Peruvian anchoveta (0.01) (Fréon et al, 2014a).…”

Achieving Sustainability of the Seafood Sector in the European Atlantic Area by Addressing Eco-Social Challenges: The NEPTUNUS Project

“…Numerous methods have been used in sustainable fishing practices to reduce the ecological impacts of bycatch, including modifications of the gear used, quotas, banning discards, and time/area closures [132]. Many researchers [126,133,134] have suggested a reframing of the narrative around sustainable seafood to incorporate the complete supply chain and a focus on reusing waste by-products as a valuable resource.…”

“…Public perceptions of sustainable seafood and climate change vary and are mainly focused on ecological concerns [133], though the impacts along the supply chain are substantial. While current perceptions of sustainability in seafood are primarily focused on ecological concerns, impacts stemming from the material, water and energy demands of the seafood supply chain can also be of increasing importance to consumers [132]. For example, in order to reduce direct potential impacts from seafood packaging, it was recommended to increase recycling [67].…”