Doug Wentzell, regional director of fisheries management with the Department of Fisheries and Oceans, addresses a news conference in Dartmouth, N.S. on Thursday, Jan. 5, 2017. The department, along with several other government agencies, was unable to determine the cause of the massive herring and marine invertebrate deaths in Southwest Nova Scotia in recent months. THE CANADIAN PRESS/Andrew Vaughan
HALIFAX — A dramatic fish kill appears to be subsiding in southwest Nova Scotia, officials said Thursday as they ruled out human activity as a cause — but acknowledged we may never know why tens of thousands of dead herring have washed ashore over the past month.
Fisheries officials say they found just 10 to 15 fish Wednesday in an area where thousands washed up at the peak of the die-off, between the Sissiboo River and Plympton.
Doug Wentzell, regional director of fisheries management for the Department of Fisheries, says those few fish are the remnants of herring that have been washing up for the last few weeks in and around St. Marys Bay.
He says tests for toxins, viruses, infections, contaminants and other possible causes have come back negative, and testing is now being wrapped up.
Officials also looked at a dramatic temperature change around mid-December, about two weeks after the dead herring first appeared, and say that may explain why crabs, starfish and other sea life also began turning up dead.
As well, officials say they found far more herring swimming in the area than normal during testing Wednesday.
The Canadian Press