A thorough investigation on the cause of death of crabs and lobsters that were washed up on the North East coast between October and December 2021 has been completed by Defra and partner agencies.

Following significant testing and modelling to rule out possible causes, they believe the deaths were potentially a result of a naturally occurring harmful algal bloom.

From evidence found during the investigation, it’s unlikely that chemical pollution, sewage or infectious aquatic animal diseases were the cause of the deaths. Follow up work in January 2022 by the Environment Agency has shown live healthy crabs present in the same area.

Evidence gathered by Government scientists and multiple agencies throughout this investigation will continue to be collated and studied. While this is no longer an active investigation, the agencies will continue to work with local fishers and remain on standby to respond if further events occur.

The in-depth investigation considered evidence from:

• Surveys by an EA boat, Humber Guardian, and shore-based monitoring teams.
• Traditional and innovative screening methods of samples of water, surface sediments, and crab which looked for over 1,000 potential chemical contaminants.
• Follow up on any indicative chemical signals, including pyridine, involving further testing of water, sediment, blue mussels and crabs.
• Washup events reported by the public and fishers.
• An analysis of crab samples for signs of infectious disease and naturally occurring marine harmful algal toxins.
• A review of environmental permits and industrial sites for evidence of abnormal discharges.
• A review of licenced marine activity in the local area (or deemed licence).
• Satellite imagery and phytoplankton samples.

While there is no food safety risk from eating crabs that have been caught in waters off the North East coast, it is unsafe to eat dead or dying crabs found on the affected coast.

The public are encouraged to continue report any incidents of concern to the EA helpline on 0800 80 70 60 and industry are encouraged to contact NE IFCA on 01482 393 515 or ne.ifca@eastriding.gov.uk.