In the United Kingdom, the growth of crustacean fisheries using baited traps has been a defining feature of coastal fisheries over the past 20–30 years. These fisheries are unusual because animals are captured alive and, if returned to the sea, have a very high survival rate (unlike finfish, which typically die during capture). For this reason, restrictions on landing undersized individuals and egg-bearing females—and voluntary or management initiatives such as v-notching—are highly effective methods for protecting a portion of the stock.
Animals protected by such measures may still benefit from feeding on bait within traps before being returned to the sea. In addition, individuals small enough to pass through the trap mesh (or escape gaps, where present) may repeatedly enter traps to feed. Fishing with baited traps may therefore act as a subsidy to the ecosystem, potentially supplementing the diets of both commercial species and bycatch.
In the latest Editor's Choice article from ICES Journal of Marine Science, Rooke and colleagues investigate bait use in the Holderness crustacean fishery (UK). Estimates of spatiotemporal fishing effort, observed catch-per-unit-effort (CPUE) metrics, and official landings data were combined to assess the potential scale of bait use in the area, and the extent to which protected commercial crustaceans may utilise this resource.
The results suggest that a substantial proportion of the area is under the direct influence of bait, and that the volume of commercial crustaceans entering traps—and potentially consuming bait—exceeds official landings by at least an order of magnitude. The study also finds evidence of heterogeneous trap distributions, likely reflecting fishers' knowledge of productive and unproductive grounds, meaning that subsidy effects are likely to be highly localised. The regular, year-round input of bait across these targeted spatial patterns is therefore likely to have ecological consequences—potentially influencing the distribution of commercial crustaceans or supporting scavenger communities more broadly.
While the self-reinforcing nature of crustacean trap fisheries has contributed to a global rise in crustacean landings, this may have come at the expense of diversity in fishing practices and target species in some regions. As climate change increasingly affects coastal seas—through shifting species distributions and unpredictable population dynamics—this narrowing of practices could pose risks to fishing communities. The fishing industry, particularly the small-scale sector with limited capacity to follow shifting stocks, needs the flexibility to adopt a range of fishing methods to target locally abundant species. With appropriate management approaches, fishing can maintain a broad footprint, lightly trodden.
Read the full paper, Estimating the extent and impact of bait use in a UK coastal fishery, in ICES Journal of Marine Science.
