Fishing Gear Efficiency and Selectivity Mechanisms

Fishing gear efficiency refers to the proportion of encountered target organisms that are successfully captured, while selectivity denotes the gear’s capacity to discriminate between desired and non‐desired species or size classes. Advances in design and deployment seek to maximise capture rates of legal‐size specimens and minimise bycatch and habitat impact. Key strategies include optimisation of mesh size and shape, incorporation of escape vents or gaps, use of visual or olfactory attractants, and deployment of novel materials or illumination. The balance between efficiency and selectivity is crucial for sustainable fisheries management, as improved selectivity reduces discarding, enhances stock conservation and mitigates ghost fishing. Integration of behavioural insights, engineering innovations and automated monitoring has led to more precise gear configurations across pot, gillnet, longline and trawl fisheries worldwide.

Research from Nature Portfolio

Recent studies have explored the use of biodegradable biopolymer baits and automated behaviour recognition to enhance the efficiency of passive gear. Trials in the Bay of Biscay assessed bio-baits formulated from shellfish and varying polymer concentrations. By combining deep‐learning tracking with supervised classification of fish responses, researchers quantified the temporal dynamics of attraction. While natural bait remained more immediately attractive, bio-baits maintained fish interest beyond four hours and reduced dependency on finite resources. The work also demonstrated that even imperfect tracking models yield robust behavioural metrics, paving the way for smarter bait development and continuous, low-impact monitoring of pot fishery performance.

Fishing Gear Efficiency and Selectivity Mechanisms publication trend

The graph below shows the total number of articles in fishing gear efficiency and selectivity mechanisms across all publications each year (not limited to Nature Index journals).

Technical terms

Catch per unit effort (CPUE): A standardised measure of catch relative to fishing effort, used to compare gear performance.

Selectivity curve: A graph showing the probability of capture as a function of organism size, reflecting gear discrimination.

Bycatch: Non‐target species or size classes captured unintentionally by fishing gear.

Ghost fishing: Continued, unmonitored capture of organisms by lost or discarded gear.

Escape vent: A designated opening in pots or traps allowing undersized or non‐target individuals to exit.

Mesh size: The length of one side of the opening in a netting panel, a key determinant of size selectivity.

References

1. Ghost fishing efficiency by lost, abandoned or discarded pots in snow crab (Chionoecetes opilio) fishery. Marine Pollution Bulletin (2023).
2. Assessment of sustainable baits for passive fishing gears through automatic fish behavior recognition. Scientific Reports (2024).
3. Effectiveness of escape vent shape in crab pots for releasing swimming crab Portunus trituberculatus in the East China sea. Aquaculture and Fisheries (2023).
4. Effect of gillnet mesh size on the capture probability and capture patterns in the Asian paddle crab (Charybdis japonica) fishery. Heliyon (2024).