Yorkshire mass crab and lobster deaths: Government close investigation for second time after 'healthy specimens' reported
The North Sea around the Tees Estuary has been affected by the issue as far south as Staithes and Whitby since last autumn, when large numbers of dead crustaceans washed up on beaches.
An investigation was launched and after causes such as pollution, disease and undersea cable disturbance were ruled out, it was eventually announced that toxic algae was responsible.
Yet fishermen are still reporting poor catches and earlier this year crowdfunded an independent study into the phenomenon by an expert, believing that recent dredging of the Tees may have disturbed harmful chemicals.
Defra agreed to re-open the investigation and conduct further testing, but have now closed it for good after reporting that healthy specimens are now being landed.
A statement from Defra said: “Defra and partner agencies completed a thorough investigation into the cause of dead crabs and lobsters found washed up on the North East coast between October and December 2021.
“Evidence gathered in the investigation showed a naturally occurring harmful algal bloom was the most likely cause of the incident, and ruled out a number of potential causes including chemical pollution, sewage, animal disease, and dredging.
“Healthy crabs and lobsters are being caught in the region and, while crab and lobster stocks will continue to be monitored, the investigation has now been closed.”
The health of crab and lobster stocks is vital to the success of the inshore shellfish industry along the Yorkshire coast.
A fishermen's union called the North East Commercial Fishing Collective, which includes members of the Whitby Fishermen's Association, refused to accept the first investigation's outcome and crowdfunded a £5,000 fee to hire marine pollution consultant Tim Deere-Jones to independently analyse samples.
Mr Deere-Jones concluded that a chemical called pyridine was behind the deaths. DEFRA had already said that pyridine was present in crab tissues tested, but said this was linked to natural processes rather than environmental factors and that it was also found in control samples of crabs taken from non-affected regions.
Pyridine is released as a waste product from a number of different industries. Mr Deere-Jones added that there could be historic deposits of the chemical dating from the Tees' days as a highly polluted river that had been disturbed by recent dredging work.