Yorkshire mass crab and lobster deaths: Algae blamed for deaths of thousands of crabs and lobsters, say officials

An investigation into the incident, which saw crustaceans washed ashore along parts of the north-east coast of England between October and December 2021, did not identify any “single, consistent, causative factor”.

But a harmful algal bloom in the area at about the same time was identified as being of significance, a report from a joint agency investigation into the incident said.

Earlier this month fishermen from Scarborough, Whitby and Redcar to South Gare, near the mouth of the River Tees, to demand a new investigation into the deaths, refuting the Government’s investigation which blamed the bloom and said they believed the blame lay with 250,000 of dredged sediment in the Tees.

But yesterday a spokesperson for the Environment Department (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 and concluded that a naturally occurring harmful algal bloom was the most likely cause.

“We ruled out a number of potential causes – including chemical pollution, sewage, animal disease, and dredging.”

The investigation by the Environment Agency, Centre for Environment, Fisheries and Aquaculture Science (Cefas) and the Marine Management Organisation (MMO) examined a range of potential causes.

Tests on dead crabs and lobsters washed up in the incident, which affected a stretch of coastline stretching from County Durham and Teesside to Robin Hood’s Bay, confirmed they had been exposed to algal toxins.

The report said that the significance of these algal toxins in the context of the deaths was not yet fully understood and Government-funded research will look into the issue.

It also said healthy crabs and lobsters are now being caught in the area and the investigation is closed.