Research undertaken by staff at the NAFC Marine Centre has shown that there is a high survival rate of velvet crabs discarded from the local fishery.
The study looked at whether discarding crabs was likely to result in mortalities and have an impact on the stocks as a whole.
In some areas around Shetland a relatively high proportion of undersized individuals are caught in creels, these cannot be landed and have to be returned to the sea. The work was carried out during a closed season in the velvet crab fishery. The closed season is designed to protect the crabs following their moult, when they cast their hard shell and are then soft-shelled for a period of weeks while they grow.
These soft-shelled crabs are also discarded, as they are not marketable, and it is thought that they may be particularly vulnerable during this time.
The study reveals that velvet crabs are fairly resilient to capture and discard, with very few discard mortalities recorded.
It should be noted that these experiments were carried out in controlled conditions. Velvet crabs are sensitive to exposure to air, so to minimise the potential impacts of discarding at sea they should be handled with care and quickly returned to the water.
