Miramichi Leader

Invasive Bass Threaten Atlantic Salmon Population

Kris McDavid

Aug 26, 2019
One of the worst-case scenarios for those working frantically to preserve and grow the threatened Atlantic salmon population in the Miramichi River system has officially come true.

Mark Hambrook, the president of the Miramichi Salmon Association, speaking in a video statement issued Thursday, said there has been a confirmed sighting of an invasive smallmouth bass within the Southwest Miramichi River watershed, and is calling on officials with Fisheries and Oceans Canada to act swiftly in order to assess and contain the problem.

Worry about smallmouth bass infiltrating the Miramichi River has been a source of anxiety for conservationists dating back more than a decade.

The non-native fish were introduced illegally to Miramichi Lake, a headwater of the river system not far from Napadogan, in 2008.

In the years since, salmon stakeholders had been pushing for DFO to eradicate the bass population within the lake using a chemical that has proven effective in similar situations elsewhere in the country.

Instead, the department has focused on attempting to contain the threat, undertaking electro fishing, inviting anglers in to fish the lake and also using gill nets and trap nets, while installing a wooden fish barrier near where the lake connects to the upper reaches of the river.

The bass was pulled from the river at McKiel Brook, not far from the small Lake Brook outflow that connects the lake to the Southwest Miramichi.

Hambrook and others have maintained for years that those efforts haven't gone far enough, and that the concerns of groups like the MSA have not been heard.

And now that this has happened, Hambrook said the situation needs to be made an immediate priority.

"We've been trying hard for 11 years, not only the MSA but all of our conservation partners, to try and get the smallmouth bass eradicated, only to be met with a brick wall from Fisheries and Oceans," he said.

"The fish are still there 11 years later, and now they've escaped the lake and are into the Southwest Miramichi – we hope there's only one or two individuals, and hopefully DFO will take the lead and mount an eradication program in the river and assess what the extent of the damage is ... but this is on them."

The Miramichi Leader has reached out to Fisheries and Oceans Canada for comment on the matter and is awaiting a reply.

The threat of the smallmouth bass establishing a population in the Miramichi watershed is one of several challenges facing the river's legendary run of wild Atlantic salmon.

A discussion paper penned for the department by members of the Canadian Science Advisory Secretariat in 2009 noted that smallmouth bass tend to thrive wherever they are introduced.

Despite not being native to the Maritimes, smallmouth bass are believed to now inhabit 69 lakes and 34 rivers in New Brunswick alone.

"When smallmouth bass are introduced into a water body, they prey heavily on smaller fish, can out-compete other fish species, and can become a dominant component of the food web," the report reads.

"There is a high likelihood of widespread establishment of smallmouth bass in the Southwest Miramichi River and in the Gulf Region rivers in general."

When it comes to the situation at Miramichi Lake, organizations like the MSA had been pushing for the government to use the chemical rotenone, which would basically poison any fish swimming in the 223-hectare lake without harming the rest of the aquatic habitat.

The idea would see stocks of the lake's native fish, about 16 species, saved prior to the chemical being added and reintroduced to repopulate after the poisoning.

Officials have so far balked at that plan, citing the cost, issues with permitting and questions over whether rotenone would be effective on a lake of that size.

The presence of smallmouth bass is just one of several threats facing the Atlantic salmon. Warmer water temperatures, the ongoing impacts of poaching, grey seal activity, the explosion of the native striped bass population, and years of commercial activities in Greenland are all believed to have had a major impact as well.

DFO reported that Miramichi salmon populations were an estimated 27,400 last year, a far cry from the peak stock size of 116,000 in the 1970s.

But the news isn't all bad, Hambrook added.

Updated fish count data from a monitoring station positioned along the river is indicating the number of returning grilse – salmon which have spent a single winter at sea – are up so far this year over last.

On the flip side, however, he said the new numbers also show that there are fewer larger salmon on both main branches of the Miramichi than there were this time last year.

Fisheries and Oceans, because of warm water temperatures, have had to close and reopen large numbers of cold water pools to angling multiple times this summer, and Hambrook said the MSA has been receiving reports of people taking part in recreational tubing on the river disturbing the salmon as well.

"Be careful out there, because the water is warm and those fish are stressed," Hambrook said. "And if you go tubing, we're getting lots of reports of tubers harassing salmon in the river ... be responsible and gently float down the river if you're coming to a salmon-holding area."

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