Working Group on the Biology and Life History of Crabs (WGCRAB; outputs from 2020–2022 meetings)

The Working Group on the Biology and Life History of Crabs (WGCRAB) provides a forum for crustacean scientists to discuss common trends and challenges faced by these fisheries in different countries. The group’s main objective is updating and providing data on landings, fisheries and biology of crab and lobster stocks, and discussing appropriate assessment methodologies that can be applied to these stocks in the ICES area.

Additional objectives include considering the impact of environmental drivers, diseases and pollution in the main commercial fisheries, reviewing research, and generating new knowledge on vital crustacean population biology. Examples were provided on fisheries for Cancer pagurus and Homarus gammarus in Ireland, France, Norway, Sweden, UK, Jersey and the Isle of Man, on Chionoecetes opilio in Norway and Canada, on Paralithodes camtschaticus in Norway, and on Callinectes sapidus in Spain. WGCRAB is progressing in evaluating and discussing assessment methods, sharing new knowledge, and working toward collaborating projects.

For this cycle of the group’s work, novel work on a disease affecting brown crabs, the presence of contaminants in crustaceans and the impact of introduced species were discussed. Several new stock assessments were proposed and presented for the first time for brown crab and European lobster, using mainly length-based methods or productions models such as SPiCT. WGCRAB recognises that further work must be carried out before achieving peer-reviewed assessments of the main ICES crab and lobster species.

Many crab and lobster fisheries lack scientific data and capacity to perform robust assessments of stock status and appropriate management advice. Moving forward, the group will continue to evolve towards implementation of stock assessments for all species considered and will assess new ways of working, such as, seeking assessment expertise from other ICES WGs, consider a longer meeting format, or creating a new assessment subgroup.

WGCRAB notes a common declining trend in CPUE and survey data observed in most brown crab fisheries, and recognizes that this message needs to be communicated widely and can be achieved with a collaboration paper to be produced in 2023. The group continues to collaborate and share data on a number of studies involving brown crab, snow crab and European lobster.

Whilst WGCRAB will move towards providing assessments of stock status for crustacean fisheries, it will continue to encourage participation from members who work on the biological studies that underlie stock assessments. The group will extend its focus into exploring genetics and stock structure of crab and lobster populations in the NE Atlantic and a new term of reference was proposed to deal with the quality of biological parameters used in stock assessments.