Salmon groups and experts proposing to eradicate invasive smallmouth bass in the Miramichi watershed say they still hope to proceed this year, although COVID- 19 is making things more difficult.
However, cottage owners on Miramichi Lake aren’t on board with the idea.
Field work is expected to resume soon, with public health guidelines in mind, on the plan to use rotenone to wipe out the smallmouth population in Miramichi Lake, Lake Brook and a portion of the Southwest Miramichi River.
Neville Crabbe, spokesman for the Atlantic Salmon Federation, said the coronavirus pandemic may affect how many people can do research on the river, but it’s important to move as quickly as possible to address the issue.
“We’re doing our best to advance this project where we’re at the 11th hour;’ Crabbe said Friday.
“If as non-governmental organizations and First Nations groups working together, we don’t put the maximum effort in here, we aren’t doing right by the Miramichi River and its ecosystem,” he said.
The group behind the rotenone plan includes the salmon federation, North Shore Micmac District Council, Miramichi Salmon Association, Maliseet Nation Conservation Council, the Miramichi Watershed Management Committee and New Brunswick Wildlife Federation.
Brian Finlayson, a rotenone expert from California advising the group, said rotenone is a plant-based pesticide that has been used by fisheries and wildlife agencies around the world since the 1930s. He said it works well because it dissipates quickly and is more toxic to fish than to mammals, birds, insects and amphibians.
Finlayson said rotenone can also be neutralized downstream from the treated area with potassium manganate, a granular oxidant commonly used in water supply systems. Once injected into the river, he said, it will oxidize the rotenone – causing it to break down within 15 to 30 minutes.
“Time is of the essence [for the treatment],” Finlayson said Saturday.”The longer we wait, the greater the chances the fish will move downstream and become more widespread in the watershed. Hopefully it’s not too late already.”
According to Fisheries and Oceans Canada, smallmouth bass were illegally introduced in 2008 to Miramichi Lake, part of the Southwest Miramichi’s headwaters. They were being held in the lake by a barrier before some fish escaped last year via Lake Brook, a narrow stream connecting the lake to the river.
Smallmouths have been spotted on four occasions in Lake Brook. In August 2019, they were discovered in the Southwest Miramichi near the mouth of McKiel Brook.
The salmon federation and other groups have pushed DFO for years to chemically eradicate the bass from the lake. They amended their previous application to the department April 8 to include treatments for the lake, stream and a IS-kilometre portion of the river.
Finlayson said the smallmouths may not only impact the already-declining Atlantic salmon populations in the Miramichi if they colonize in the river, but they also could affect brook floaters, freshwater mussels and other aquatic species in the lake.
“It certainly won’t be good news for the Atlantic salmon in the river, especially if the bass get loose and spread throughout the watershed;’ he said. “That could be the final nail in the coffin for salmon.”
Trish Foster owns a cottage on Miramichi Lake and raised concerns about the pesticide proposal on behalf of a camp owners’ committee. She said there are many other issues affecting salmon, such as deforestation, herbicide spraying, overfishing, predators at sea, parasites and climate change, among others.
She said cottage owners are worried about how poisoning the lake, brook and a section of the river could affect their safety, other fish species and the ecosystem, along with the rest of the Miramichi watershed.
Foster said she’s also concerned the substance the working group plans to use is not purely rotenone, but is actually a harsher chemical that contains rotenone as an ingredient.
“Two cottages on the lake source their water from the lake,” she said. “We’ve been told that, three days later, we can drink the water and let kids swim in it. None of us believe that should be happening.”
Foster said an environmental impact assessment is needed to determine the potential effects of poisoning the lake on the area, but Crabbe said the provincial government is reviewing the updated application to determine whether any further studies are needed.
Foster said camp owners also disagree that treating the lake with pesticides is effective, and they’re worried multiple doses of poison will be needed.
“Our lake does not lend itself to this process,” she said. “We don’t see this as a solution to the problem of salmon populations declining.
“We have some very serious concerns, and I would think anyone on the Miramichi River would be worried about the idea of poisoning several kilometres of it.