Crab Ecology and Fisheries Management

Crabs occupy a broad range of marine and estuarine habitats from intertidal zones to the deep sea, serving as key benthic predators, scavengers and ecosystem engineers. Their life cycle is defined by successive moults, during which growth and morphological changes occur, culminating in a terminal moult for some species. Feeding habits vary widely, encompassing detritivory, carnivory and omnivory, and influence nutrient cycling and food-web dynamics. Many crab populations support globally significant fisheries, with annual landings measured in hundreds of thousands of tonnes. Management approaches have evolved from simple size and season regulations towards more holistic frameworks incorporating stock–recruit relationships, habitat protection and ecosystem-based quotas. Emerging challenges include the northward shift of cold-water species under global warming, the rise of invasive populations creating diplomatic and governance disputes, and the need to balance social and economic interests with conservation. Advances in physiology, genomics and predictive modelling now inform adaptive harvest strategies, gear design, property-rights regimes and spatial planning, fostering resilience in both crab populations and dependent fishing communities.

Research from Nature Portfolio

Recent studies have illuminated the endocrinology and molecular regulation of the male snow crab after its terminal moult. Researchers measured circulating levels of methyl farnesoate before and after the final moult and conducted eyestalk transcriptome analyses to identify gene networks controlling hormone synthesis and degradation. They discovered a pronounced increase in methyl farnesoate titres post-moult, likely driven by downregulation of degrading enzymes and inhibitory neurohormones, and linked to activation of biogenic amine pathways that underlie behavioural shifts related to mating success. These findings deepen our understanding of crustacean reproductive biology and could inform broodstock management and stock enhancement programmes.

Crab Ecology and Fisheries Management publication trend

The graph below shows the total number of articles in crab ecology and fisheries management across all publications each year (not limited to Nature Index journals).

Technical terms

Terminal moult: The final moulting event after which a crab ceases to grow and attains reproductive maturity.

Methyl farnesoate: An endogenous juvenile-hormone analogue in crustaceans that regulates growth, moulting and reproductive processes.

Sea ice extent: The total area of ocean surface covered by a minimum concentration of sea ice, used as an indicator of habitat availability for ice-dependent species.

User rights: Legal entitlements defining who may fish, under what conditions and for how long, forming the basis of access regimes in managed fisheries.

References

1. Rethinking user rights of profitable marine invasions: Lessons from the Norwegian Barents Snow Crab fishery. Ocean & Coastal Management (2024).
2. Eyestalk transcriptome and methyl farnesoate titers provide insight into the physiological changes in the male snow crab, Chionoecetes opilio, after its terminal molt. Scientific Reports (2023).
3. Sub-Arctic no more: Short- and long-term global-scale prospects for snow crab (Chionoecetes opilio) under global warming. PLOS Climate (2023).