Climate change hasn’t hit N.L. aquaculture hard yet, says MUN professor — but it’s coming | CBC News

A Memorial University ocean sciences professor says climate change hasn’t hit Newfoundland and Labrador’s aquaculture industry hard yet — but it will.

Paul Snelgrove, a MUN professor and the associate scientific director of the Ocean Frontier Institute, said diseases spread more rapidly in warmer water, and if ocean waters heat beyond the threshold of a fish or invertebrate, mortality could become more prevalent.

“Thinking about fishes and mussels, which are the main species that are grown around here, both are temperature-sensitive, and growth rates will vary as a function of temperatures,” he explained. 

The biggest concern with warmer temperatures, he said, is their  effect on the entire ocean environment, including on the food chain.

Mussels, for example, feed on natural phytoplankton, Snelgrove said, and changes to the micro-organism can have ramifications on mussels’ growth rates and even their flavour when they’re consumed. 

“The main issue that overrides everything is whether you increase mortality, because of course that will reduce the profitability of aquaculture and the amount of product that’s actually eventually delivered to market,” he said.

Jamie Baker, executive director of the Newfoundland and Labrador Aquaculture Industry Association, says everyone in the sector is bracing for it.

Baker told CBC News there haven’t been “any immediate impacts just yet” but warming oceans will be a challenge for everyone in the long term.

“When you start seeing the temperatures creeping up, obviously it’s something everyone pays close attention to and everybody’s putting a lot of work into keeping a close eye on,” he said.

People in the industry know the challenges of ocean dynamics and how species react to the changing environment, he said.

“I think this is probably something we can all agree on — the entire marine sector — climate change is going to be the biggest challenge facing all of us whether it’s fisheries, angling, farming… I mean, you name it.”

This summer has been “status quo” with respect to the changing temperatures, he said, and people working in the industry have so far been able to adapt to the changing climate.

“We have people who know what they’re doing, who understand what’s happening in the water probably better than anyone,” he said. 

“That’s your first line of defence when it comes to dealing with any sort of environmental issue, particularly temperatures and weather events.” 

Snelgrove said it’s hard to predict what will happen in the long term.

“But certainly change is ongoing and it is suggested that these changes will continue and perhaps get even worse over time,” he said.

Migrating species

Newfoundland and Labrador is wedged between the subarctic and a temperate environment, he said

“As these ocean waters warm more and more, we may tend to see more of a shift towards these temperate species,” he said, adding the effect has already been seen in shrimp. 

“Shrimp are clearly moving further north than they have been historically,” he said. “And so for a fishery, of course, that’s important because it’s moving the shrimp away from the more accessible areas where we live toward more northern areas that are longer distances for ships to travel in order to capture them.” 

MUN research professor Kurt Gamperl says haddock is another example of species that are moving toward the Earth’s poles.

“I hear from colleagues that obviously haddock weren’t really a significant fishery on the south coast of Newfoundland, but there’s a lot of haddock around now.”

Gamperl has been working in the industry for about three decades, with both cold and warm temperature species, and recently built a lab in the Bahamas to better understand how tropical and subtropical fish operate and adapt to change. 

Though Newfoundland and Labrador has not seen drastic changes in aquaculture because of climate change, he said, temperatures are getting close to the point where they’re going to potentially start affecting salmon, which will not eat after the water temperature rises above 18 C. 

And, Gamperl said, climate change can increase storms and extreme weather events, which can also affect how the industry is managed.

One of the bigger challenges, he said, will likely be sea lice, which will have more time to reproduce in warmer waters. Sea lice attach themselves to fish, including salmon, and feed on them to survive. Their larvae will grow quicker in warmer temperatures, and get larger earlier in the season, he said.

“So the warm water temperatures means that the industry will be challenged with higher life counts and possibly higher impacts on the fish.”

We know there are going to be other challenges. How severe those are, we just don’t know.– Kurt Gamperl

In Tasmania, Gamperl said, surface ocean temperatures have reached 24 C and the industry is looking to move to cooler waters.

“I don’t think in Newfoundland the waters are going to warm that much,” he said. “But the industry is going to have to adapt, and there’s a number of ways they could potentially do that.”

Selective breeding, changing management protocol and advancing technologies can be used to mitigate the effects of climate change, said Gamperl, and there’s time to do that.

“I would say it’s not an immediate worry and that it is going to have small effects. Long term is hard to predict,” he said. “We know there are going to be other challenges. How severe those are, we just don’t know.”

Gamperl said selective breeding could take four or five years, but it could result in fish that are more tolerant of higher temperatures. 

“I see some impacts coming in the next five to 10 years,” he said. “it’s not anything that the industry can’t actually adjust to.” 

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