Independent findings had also suggested that pyridine was unlikely to be the cause. Previous speculation about the shellfish deaths had blamed harmful algae, while a report commissioned by fishers linked the deaths to dredging in the River Tees and the presence of pyridine.
An independent panel of experts had suggested that a new disease or parasite in UK waters was a more likely cause. Cefas reanalyzed shellfish samples for pyridine using a new testing method and found low levels of the chemical but concluded that it was unlikely to have caused the deaths.
The findings aim to settle the debate over the cause of the shellfish die-off, which had raised concerns among the public and fishermen. Some local officials expressed skepticism over the latest findings and criticized the government's handling of the investigations into the matter.