European genes found in wild Atlantic salmon cause alarm
A study into the wild Atlantic salmon population of Canada’s Inner Bay of Fundy is raising alarm among conservationists concerned about the impact the local aquaculture industry may be having on the species.
A newly released study that reviewed data collected over the past 15 years found a breed of hybrid salmon have taken root in the waters of the Inner Bay of Fundy.
The study was a review of the Science Associated with the Inner Bay of Fundy Atlantic Salmon Live Gene Bank and Supplementation Programs conducted by Canada’s Department of Fisheries, Oceans, and the Coast Guard (DFO) through the Canadian Science Advisory Secretariat.
The preamble notes that the returns of Atlantic salmon to the inner Bay of Fundy – a population that once existed in the tens of thousands – began to decline in the 1980s. That decline continued in the region so that in 1999 only 250 adults are believed to have returned to 50 rivers in the inner bay. The inner Bay of Fundy Atlantic salmon was assessed as endangered in 2001. In 2008, a recovery potential assessment conducted by the Canadian government forecasted the extinction of the species without the support of a program known as live gene banking (LGB).
To prevent the extinction of the genetically distinct group, DFO captured 1,029 juveniles and transferred them to biodiversity facilities in the Canadian Maritimes for captive breeding and rearing. The LGB project has been in operation for three salmon generations – 15 years – and shows “little evidence of progress towards the re-establishment of self-sustaining populations,” according to the new study.
“Results from several population genetic analyses are all consistent with extensive and ongoing gene flow from non-local (likely outer Bay of Fundy) sources into the Big Salmon River gene pool, and this could represent a risk to the conservation of [inner Bay of Fundy] genetic characteristics in the ... LGB population,” the study said.
It is now illegal to import European salmon into North America, but imports were allowed in various forms through 2006. The DFO study pointed to the likelihood that European salmon that escaped from farms in Eastern Canada, or hybrids between European and North American salmon, spawned in the inner Bay of Fundy between 1997 to 2012.
According to DFO reports, numerous fish farm escapes occurred during that time period. Most significant among them was the 2010 loss of 174,000 Atlantic salmon from three aquaculture sites in Western Passage (between Passamaquoddy Bay and Gulf of Maine) and Grand Manan. In addition, four potential breaches in nets were observed in Seeley’s Cove and Maces Bay, New Brunswick, in 2012, though no change in biomass were observed. In 2013, another 1,000 to 1,500 salmon escaped from a damaged pen in Western Passage. And in 2015, 40,000 salmon escaped three cages off Grand Manan.
Neville Crabbe, the communications director for the Atlantic Salmon Federation, a non-governmental organization dedicated to the conservation of wild Atlantic salmon, called the findings "alarming."
His colleague, ASF Director for Regional Programs Geoff Giffin, said his organization would like to see DFO to carry out more extensive genetic testing to determine if, in fact, farmed fish are getting into the gene pool. If they are, the ASF wants steps taken to cull the non-native species, which is one of the recommendations in the review. The ASF also wants DFO to compel the aquaculture industry to release genetic databases so that the source of the foreign DNA can be identified.
"Whether or not the genetics are European or local genetics, if they are escaping from farms, farmed salmon are domesticated animals and the science is very clear on the impacts of domestication on salmon,” Giffin said. “Over time, their offspring become less fit, their survival goes down, [and] they are less adapted to the local environment."
In an interview with the CBC, Atlantic Canada Fish Farmers’ Association Executive Director Susan Farquharson also urged the DFO to conduct more extensive studies on the issue. However, she called for the retraction of the new report.
“Simply put, the report is just poor science,” she said. “The DFO report notes the presence of European-ancestry fish in the Bay of Fundy but it clearly states that a full analysis was not conducted and it recommends that it be done.”
Farquharson said the industry only uses Saint John River-strain fish and has been screening for European gene variants for 20 years.
"DFO has the regulatory authority to check for genetics in our fish any time they want through introduction and transfer regulations,” Farquharson said.
Photo courtesy of Canada’s Department of Fisheries, Oceans, and the Coast Guard