Fish mystery: researchers unsure what killed tens of thousands of herring

The Department of Fisheries and Oceans has yet to identify the cause of the herring die-off in southwest Nova Scotia.

“What it is, is a bit of a mystery,” said David Whorley, director for Fisheries and Oceans Canada in southwest Nova Scotia.

The first sightings were reported late last month along the eastern edge of St. Marys Bay, and more dead fish were reported on beaches in the Annapolis Basin and farther west, near Pubnico.

Fisheries and Oceans spokesman David Whorley says a battery of tests have so far turned up nothing in terms of a plausible explanation.

However, he stressed that several possible causes have been ruled out, including the fact that no infections or infectious agents have been detected.

As well, Whorley says examinations of the small, silvery fish have failed to find any obvious signs of damage, and tissue samples appear to be clear of any type of virus or harmful bacteria.

Still, Whorley said more testing is on the agenda.

People should report any sightings of dead herring, but they should refrain from collecting samples, as a precaution, he said.

Agencies/Canadajournal