‘It’s not human-caused’: Environmental factor likely trigger of fish kill in St. Mary’s Bay

Published on January 19, 2017

Department of Fisheries and Oceans Canada regional director of science Alain Vézina explains to reporters that the recent marine life mortalities were likely killed by a confluence of environmental factors, and not caused by human activity or infection.

©Chris Muise

HALIFAX, NS - “Some sort of environmental event” is the likely cause of the recent swath of herring mortalities that washed up along the shore of St. Mary’s Bay, provincial government representatives heard Jan. 19.

Bumping back a planned meeting on the lobster fishery, the Standing Committee on Resources invited members of the Department of Fisheries and Oceans Maritime Region and the provincial Department of Fisheries and Aquaculture to explain their findings on what caused the recent fish deaths.

“We certainly know what it isn’t,” says Alain Vézina, regional director of science with the DFO. “It’s not human-caused.”

Vézina told the committee, as well as a scrum of journalists after the meeting, that extensive tests done on the herring remains and the environment excludes any sort of man-made cause or any viral or bacterial pandemic of any sort.

“We have ruled out anything that would be caused by pollution, pesticides, or natural contaminants in the environment. We have ruled all that out,” says Vézina. “What’s left, really, is some sort of environmental event.”

We have ruled out anything that would be caused by pollution, pesticides, or natural contaminants in the environment. Alain Vézina, regional director of science with the DFO

The DFO and DFA said their findings suggest a perfect storm of environmental factors came together to cause this larger-than-usual fish kill. Sudden cold snaps in temperature, high winds, high tides, and fish behaviour all likely played a part in this event – although in exactly what way is still unclear.

“There’s a confluence of events here that may have led to these events, but we don’t know exactly how these things interacted,” says Vézina, who noted that most of the herring they observed in the region were juvenile – natural wanderers, according to him. Clogging up the waters was another possible factor, he added.

The team from the DFO and DFA fielded questions and concerns from the members of the committee, ranging from climate change concerns, the rumours of red tide, concerns over pesticides, and more.

A panel of members from the Department of Fisheries and Oceans Canada (DFO) and the NS Department of Fisheries and Aquaculture (DFA) sat before the Standing Committee on Resources to share their findings on what caused the recent marine life mortalities on Nova Scotian shores.

©Chris Muise

More science spending needed?

Queens-Shelburne MLA Sterling Belliveau addressed what he characterized as the “elephant in the room” - the question of more science spending in our fisheries for better monitoring capacities.

“In the last decade, we have seen the federal government slash science on the fisheries,” says Belliveau. “I’m suggesting that we need to have better monitoring in place...do you think the monitoring presently around our culture is adequate to answer the question of these kills?”

Vézina replied that some of that money will likely be invested in the region, but the event witnessed along St. Mary’s Bay was a rare occurrence, small in scale compared to the overall allowable catches, and one difficult to catch before it happens.

He says that the kind of province-wide monitoring Belliveau suggests would not be feasible.

“It would be very hard to develop a monitoring system that would be affordable, that would allow us to detect this event somewhere else. It’s very unpredictable,” says Vézina.

And, he warns, this sort of thing will happen again – it’s just impossible to say when. “These events have happened since the dawn of time...(they’re) not frequent. They’re unusual, but they do occur.”

Vézina says that they’ve set up temperature monitoring equipment to keep an eye on the area for a little bit longer, just in case there is a pattern to detect, but concludes that the DFO and DFA are basically in stand-by mode – basically, case closed. But they’ll be ready to move if another incident occurs in those waters.

“If there was a recurrence of events, then we would be ready to redeploy very quickly on-site, to see what’s happening,” says Vézina.

The future of aquaculture

The DFO and DFA believe that this event is likely over, and that fish stock in the region is still healthy. Healthy enough, even, to look to growing our region’s aquaculture even further.

Bruce Osborne, executive director of Fisheries and Aquaculture, says that Nova Scotia hasn’t yet reached its full aquaculture potential, and meeting that potential will be vital in the years to come.

“The world is hungry for seafood right now,” says Osborne. “Future growth for seafood, to feed the world the protein that it needs and demands, is going to come from aquaculture. There’s always strong, latent interest in people to establish aquaculture businesses in Nova Scotia.”