Fish deaths ‘perplexing,’ says federal scientist
HALIFAX • Scientists have yet to find a cause for the massive fish kill off southwestern Nova Scotia, but one federal official said that based on testing so far, he doesn’t believe there is a reason to be concerned.
Kent Smedbol, manager of population ecology for the Department of Fisheries and Oceans (DFO), said Friday that while the lack of an obvious cause is “perplexing,” he doesn’t personally believe there is need for concern at this point.
“I can’t speak for the department, personally at this point from most of the studies that have been undertaken, the evidence provided to date, I don’t think there’s a great cause for concern,” Smedbol said in a news conference.
Since late November, thousands of dead herring have been found in a 100-kilometre swath from St. Mary’s Bay to Tusket, with most found between the mouth of the Sissiboo River and Plympton. More recently, scores of starfish, clams and lobster have also turned up dead, and a dead whale also washed ashore on Whale Cove.
Smedbol said scientists conducted testing on the Bay of Fundy on Thursday and preliminary results for temperature, salinity and dissolved oxygen came back normal.
A camera scan of the bottom of St. Mary’s Bay also showed normal conditions and an abundance of live lobster in the area.
“That would indicate that the die off was unlikely due to an environmental event, because you would expect more broad-scale die offs across species particularly in the benthos, animals on the bottom,” Smedbol said. “Things seem to be pretty normal on the bottom of St. Mary’s Bay.”
Fish kills are not uncommon, especially in fresh water, but the last kills of comparable size involving herring occurred in the Bay of Fundy in 1976 and 1979, one official said Friday.
Smedbol said that to date scientists have not turned up evidence of disease, parasites or toxins, and nothing has “stood out” in the physical examination of the fish and other marine life.
He said DFO would be conducting further tests on recently collected invertebrate samples and was also willing to look for any connections by examining the carcass of the humpback whale, which he described as being in “a fairly advanced state of decomposition.”
“We have certainly worked through what I call the usual suspects and the fish health lab is working on a few more viral probes ... we will have to wait and see what happens over the next week,” said Smedbol.
He said a storm during the holiday period caused a sudden temperature drop to -5 C in shallower waters near Digby.
The temperature dip and rough surf may have caused some creatures living on the bottom to die and wash up, Smedbol said, however he cautioned the examinations have turned up nothing conclusive.