A new disease or parasite in UK waters may have killed thousands of shellfish off the coast of the North East and North Yorkshire, according to a report.
A panel of 12 experts found it was “as likely” as a new pathogen to cause death in late 2021.
They said regular dredging of the Tees River is “highly unlikely”, while main dredging is “highly unlikely”.
They also eliminated the chemical pyridine as “unlikely.”
And it’s “unlikely” to be caused by a harmful algal bloom, but the available data “can’t be definitive,” they said.
While the government had previously blamed harmful algae, fishermen commissioned a report suggesting this was due to pyridine used in the marine industries.
‘Twitching’ dying creatures
Previous academic research sponsored by the fishing industry had suggested that the deaths were likely due to chemicals from dredging at the mouth of the Tees River to protect channels for port traffic.
The mass demise of marine life on the 40-mile (70km) coastline from Hartlepool to Whitby saw crustaceans wash ashore between October and December 2021, along with dying creatures, “twitching” and displaying lethargic behavior.
Although there is no direct evidence of disease or parasites, the new report added that theory could explain this movement in shellfish.
But he said a combination of factors, rather than one considered by the board, may have led to “unusual” deaths.
The Department of Environment, Food and Rural Affairs (Defra) said the panel consisted of experts from academia and industry with “a range of knowledge and experience”.
Tammy Horton of the National Oceanographic Center, one of 12 experts, said the process was “interesting but frustrating.”
“I wish we could come to a conclusion but none of it is definitive,” he said.
“We found more questions than answers.
“We were able to overlook something, but not confidently control something.
“We didn’t find evidence of a new pathogen – we’re just saying it could be a new pathogen.”
He added that it is “highly unlikely” that a pathogen affecting crabs would pose a threat to human health.
While the panel said there is a possibility of re-examining samples taken in 2021, it added that “it may not be possible”.
Another of the panel’s experts, Crispin Hallsall, an environmental chemist at Lancaster University, said his lab has not done any additional analysis.
‘Explore all roads’
“We only got together in December,” he said.
“This is desk work. We tried to explore all these avenues.”
But he said this report “soothes the pyridine story.”
Lawmakers investigating the shellfish deaths had previously criticized the government-appointed investigation for “lack of transparency”.
The Environment, Food and Rural Affairs Committee had expressed concerns about the lack of transparency and communication regarding the report, including explaining which experts were selected to form the panel.
Pathogens known to cause similar symptoms are causing the death of crustaceans worldwide, the report said.
He said no significant pathogens were identified in the North East case, but that “full molecular screening was not performed during the initial investigation.”
Defra chief scientific adviser Gideon Henderson said the report, by “leading marine scientists”, “could not identify a single clear cause” but pointed to those more likely to explain the outbreak.
Conservative MP for Middlesbrough South and East Cleveland Simon Clarke said it was now “absolutely clear” that the deaths were not “caused by Tees’ capital or maintenance screening or anything else associated with the Teesworks site”.
He said it was a “concern” that investigators were detecting an unknown pathogen, adding: “There is much more to be done now to investigate this and also to look at the support we can offer our local fishermen to recover.”
Fishermen, including Adrian Noble in Whitby, described the situation with the deaths as “terrible”.
Redcar Conservative MP Jacob Young said that after “doomsday scenes” on the beaches, “we now need to focus on how we’re helping our fishermen rebuild the industry on Teesside.”
Tees Valley Mayor Ben Houchen said the report “clarifies” that neither dredging nor working for free port played a role in the death.
“When I was elected, I promised the ex-steel workers on that site that I would create a new and thriving industry of the future with thousands of quality local jobs for local people,” he said.
“Today, with the backing of science, we can look each one in the eye and say that the work we do in a field that means so much to so many people is safe and of the highest possible standard.”
He said the deaths were “devastating” for the fishing community and that it was crucial that the government support fishermen and help them recover.
But Alex Cunningham, Labor MP for Stockton North, said the matter was “not quite closed” and called for further investigation, and Middlesbrough’s Labor MP Andy McDonald said the report “resolved nothing”.
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