North Yorkshire Council has backed calls for a public inquiry into the unexplained mass deaths of shellfish off its coastline.
Thousands of marine creatures, including crabs, have washed up dead between Hartlepool and Whitby since late 2021.
Crab and lobster fishermen in Whitby say their livelihoods are at risk because of reduced catches, which many blame on dredging in the river Tees.
Previous research, supported by the fishing industry, suggested the deaths could have been due to the chemical pyridine, possibly from dredging in the mouth of the River Tees.
The Department for Environment Food & Rural Affairs said it was likely to be due to naturally-occurring harmful algae and environment secretary Therese Coffey has previously said no further analysis will take place.
However, a panel of 12 experts said in January no definitive cause had been found, but they ruled out pyridine and concluded it was possible a disease or parasite new to UK waters was responsible.
Labour councillor Neil Swannick, whose Whitby division has been affected by the die-offs said: ‘I can't think that anybody would not now understand that this is a big issue for fishing communities on the North East coast.
‘The net result was that there will be pressure on the secretary of state to convene a public inquiry, which was the original aim of my motion.’