Tees Estuary mass marine deaths: Thousands of dead crabs washed up on north-east beaches including Saltburn and Staithes as Environment Agency launch investigation

The phenomenon was first reported in the Hartlepool and Redcar areas over the weekend but photographs have now emerged of dead crustaceans washed ashore as far south as Saltburn and Staithes on the Yorkshire coast.

All of the affected beaches are in the vicinity of the Tees Estuary, which the Environment Agency is now investigating for potential industrial pollution incidents.

Samples have been taken from the crustaceans, water and sediment for laboratory analysis, to see if pollution was the cause.

Lab analysis will also be used to test the dead crabs for disease.

A Environment Agency spokesman said: “Samples of water, sediment, mussel and crab have been collected and are being sent to our labs for analysis, to consider whether a pollution incident could have contributed to the deaths of the animals.”

Anyone who sees pollution affecting wildlife is asked to call the Environment Agency on 0800 807060.

Witnesses claim they first began seeing the dead marine life in early October. The deaths will also have a knock-on effect on the wider ecosystem, as many other species rely on crustaceans for food.

A deceased porpoise has also been found on a beach in Redcar and dead fish have been reported, suggesting the catastrophic events could be related - as could mass seabird strandings and deaths reported all along the North Sea coast, including in Filey and Runswick Bay, in September.A Teesside University marine pathologist told the BBC that the event could have occurred up to a month ago with the effects only just becoming apparent.

Redcar's Conservative MP, Jacob Young, has raised the issue in parliament.