The province has given the go-ahead for Cermaq Canada to use up to 2.3 million litres of a pesticide called Paramove 50 to remove sea lice from fish at 14 salmon farms in Clayoquot Sound, but opponents fear the mixture of hydrogen peroxide, surfactants and other chemicals will harm other species and weaken the immune system of farmed fish, making them more likely to contract diseases that could infect wild fish.

Bonny Glambeck, co-founder of Clayoquot Action, a group circulating a petition against use of the pesticide in Clayoquot Sound, said studies show the pesticide can persist in the surface layer of the water, home to marine organisms, such as Dungeness crab, prawns, young salmon and herring.

“Right now the wild salmon smolts are migrating and using the shallow areas to make their way out to the ocean and this is where it will end up when it is dissipating,” she said.

The bigger problem is that it can suppress the immune systems of farmed salmon for two weeks and that means they are more susceptible to viral outbreaks such as piscine reovirus, Glambeck said.

“So just as the young salmon are passing by the farms, we could shock these farmed fish into getting PRV or that becoming HSMI (heart and skeletal muscle inflammation disease) which is deadly to wild salmon,” she said.

Recent studies have confirmed a link between PRV, which is common among farmed salmon, and HSMI.

Although the hydrogen peroxide mixture, called Paramove 50, has been used at other sites in B.C., it has never before been used in Clayoquot Sound and the provincial government says steps are being taken to ensure the pesticide is well-diluted before it is discharged.

A permit application, submitted by Cermaq to the B.C. Ministry of Environment, requests permission to use the pesticide between January 10, 2018 and January 9, 2021 at fish farms in Fortune Channel, Bedwell Sound, Cypress Bay, Herbert Inlet, Millar Channel and Shelter Inlet.

A proposal to pour pesticide directly into pens protected with tarpaulins was turned down and the province is demanding that a well boat be used to reduce the amount of pesticides and minimize the effect on other marine organisms.

“The treatment bath, inside the well boat, will begin naturally breaking down as additional seawater is added before it’s filtered and discharged into the ocean far from shore,” Environment Minister George Heyman said in an e-mailed statement.

In 2011, over 13,000 farmed Atlantic salmon were killed at an east coast fish farm after a well boat treatment that used Paramove 50, according to an incident report filed with Health Canada.

In Norway, 126,000 farm fish died in 2016 during delousing treatment, an event fish farming company SalMar said was likely due to overexposure to hydrogen peroxide.

The government is continuing to look at whether sea lice treatments are scientifically supported and consistent with international best practices and a new interim policy, to guide statutory decision-makers, demands more stringent information-gathering and reporting, Heyman said.

That interim policy will be reviewed “over time” to ensure it is having the desired effect, he said.

“We take very seriously the concerns related to sea lice treatment expressed by First Nations and the public as the the protection of our waters and health of our wild fish stocks is paramount,” he said.

The pesticide Paramove 50, which stuns sea lice, meaning they fall off fish as they rub up against each other, is being used instead of antibiotic insecticides administered in feed, because, globally, sea lice are becoming resistant to antibiotics given to farmed fish.

However, Cermaq says the company wants to use Paramove 50 because the hydrogen peroxide bath treatment has a low environmental impact and is a more natural way to manage sea lice than feeding pesticides.

“It’s important that, as farmers, we have multiple tools in the box to allow us to effectively manage sea lice on our marine farms,” said Cermaq Canada managing director David Kiemele in an e-mailed response to questions from DeSmog Canada.

“The request and subsequent approval for the use of Paramove 50 was our first step in achieving a multi-faceted approach to integrated pest management,” said Kiemele, adding that hydrogen peroxide has been used internationally and in other areas of B.C. without negatively affecting the environment.

The Cermaq website points out that “hydrogen peroxide is almost the same as water, with just one more oxygen molecule,” and that, as long as the treatment is used properly, there are no risks to wild or farmed fish.

The Cermaq website emphasizes that fish farmers take good care of their fish, which are their livelihood, and many steps are taken to ensure the treatment is done properly.

However, for Glambeck, the heart of the issue is that the discussion should not be about the best poison to put in B.C.’s coastal waters, but how to move fish farms out of the ocean.

“It will be a couple of years and then another chemical will be needed. We need to look for long term solutions,” she said.

“The problems of disease and sea lice are global fish farm problems that the industry has not been able to solve — and they are not trying to solve them because of concern about the environment but because it is costing them a lot of money — so the industry globally now is looking towards closed containment,” she said.

Land-based farms are the answer, for the industry and for wild fish, and both levels of government should be working at a transition strategy to support fish farm workers and communities, Glambeck said.

Two major land-based fish farms are opening in Maine, with the global trend towards land-based containment, and B.C. is going to be left out of the game if companies insist that ocean pens are the only way to go, she said.

“We are going to be stuck with 1980’s technology. Our governments need to be investing in moving this industry forward into the new millennium,” Glambeck said.

“At the same time we are losing our wild salmon and allowing them go the same way as the East Coast cod. All the markers are there, the science is there to show we really need to intervene and get these farms out of the ocean,” she said.

Doug Donaldson, Minister of Forests, Land and Natural Resource Operations, who is in charge of provincial aquaculture tenures, has said that the province is interested in moving to closed containment and, with 22 fish farm tenures coming due for renewal in June, both the industry and environmental groups will be watching closely.