Report by Rachel Bullock
Fishermen struggling to make a living are calling for more proof from Government over the deaths of thousands of shellfish along the region's coastline.
According to fishermen in Whitby, shellfish trade is down 90 per cent in the region with some now being forced to use food banks.
It comes nearly four months after dead crabs and lobsters were first reported to have washed up on the region's shores.
The Department for Environment, Food and Rural Affairs (DEFRA) has attributed the most likely cause to the naturally occurring harmful algal bloom - but the fisherman remain unconvinced.
'We need more evidence'
James Cole, chair of Whitby Fishermen's Association, said: "In all my experience as a fishermen over 35 years I've never known an algal bloom of this magnitude doing this much devastation.
"We need more evidence of what's happened, we need more testing, we need more people to come. We've had nobody with any guidance come and see us and help us out of this situation.
There is concern that pollution from decades of heavy industry on the River Tees may be partly responsible, with the chemical pyridine highlighted in particular.
Calls from fishermen for more clarity from Government has gained support, with the local MP now involved.
Robert Goodwill, Conservative MP for Scarborough and Whitby, said he has been meeting with the fishing minister - with another one set for Wednesday.
He told ITV News Tyne Tees he would look into how strong the evidence is for algal bloom being the cause.
He also said he wanted to see more detailed data on pyridine and whether it could provide an explanation.
Dr Gary Caldwell, marine biologist from Newcastle University, said that algal bloom was a more likely explanation though further testing should not be ruled out.
He said: "Large mortality events down to algal blooms is increasing and we think it's possibly linked to climate change.
"But that's not saying that there aren't other factors that may be involved, because the site is impacted by industrial pollution through the Tees Estuary."
'Harmful algal bloom'
And DEFRA repeated today that their investigation points to algal bloom as the most likely cause.
A spokesperson said: "Our sampling established that no pyridine was present in the water or sediment samples we collected but was detected in crab tissue from both impacted areas and non-impacted areas elsewhere in the country.
"As such, any levels detected in crab tissue are likely to be linked to biological processes and not necessarily from the environment.
"Significant testing and modelling has ruled out a number of potential causes including chemical pollution, sewage, animal disease or dredging.
"The most likely cause of the deaths seems to be a naturally occurring, harmful algal bloom."