- Independent government-commissioned study finds a pathogen new to UK waters as as likely as not cause of late 2021 mass crustacean deaths.
- Report says maintenance dredging was very unlikely to have caused deaths and would not have produced enough pyridine or other toxic chemicals.
- Earlier government study blamed a natural harmful algal bloom; an industry-backed academic study pointed to pyridine pollutant linked to dredging.
- The die-off affected crabs, lobsters and other crustaceans along Hartlepool to Whitby from October to December 2021.
- Chief scientific adviser Patrick Vallance welcomed the report, saying options and likelihoods are clearly laid out despite no definitive answer.
What caused the mass death of crustaceans off the coast of northeast England in late 2021? A new finding on Friday brought relief to the government, which is developing a flagship new “freeport” in the region.
The customs-free zone in Teesside is one of several planned that are aimed at showing off Britain’s “post-Brexit freedoms” in trade, according to the government.
Some in parliament called this week for dredging at that and other freeport sites to be suspended in case it was the cause of the die-off of crabs, lobsters and other crustaceans from October to December 2021.
A first study by government scientists into the mystery phenomenon blamed a “naturally occurring harmful algal bloom” stretching from the towns of Hartlepool to Whitby.
Then, a study by academics backed by the fishing industry pointed to an industrial pollutant called pyridine, possibly linked to the dredging.
Teesside has historically been associated with heavy industry, particularly chemical plants.
But the latest government-commissioned study by independent experts said it was “as likely as not that a pathogen new to UK waters” was the cause.
Maintenance dredging, required to keep the port open, was also “very unlikely” as the cause, failing to generate enough pyridine or other toxic chemicals to kill the crabs.
Patrick Vallance, the government‘s chief scientific adviser, welcomed the report.
“Whilst with the current data there cannot be a definitive answer, the options for possible causes and an analysis of likelihood are clearly laid out in the report,” he said.


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