Live gene bank only hope for inner Bay of Fundy salmon
The survival of Atlantic salmon in the inner Bay of Fundy is now almost entirely dependent on two federal fish hatcheries, according to a new and dire population estimate released by Fisheries and Oceans Canada.
The report said fewer than 105 adult Atlantic salmon in total are returning each year to the 50 rivers in the inner Bay of Fundy in New Brunswick and Nova Scotia.
The salmon making it back are almost entirely from two federal government hatcheries where wild fish were first taken 21 years ago for captive rearing in a live gene bank.
“Under current conditions, it is highly unlikely that adult returns to these rivers can be maintained without the support of the Live Gene Bank program, given the lack of juvenile production from natural spawning,” the report concluded.
The report is based on modelling, surveillance and analysis from 2013 to 2017.
Even the river with the biggest returns, the Big Salmon River in New Brunswick, saw just 32 adults make it back to spawn in its best year, 2015.
Tim Robinson, general manager of the habitat recovery program in the Petitcodiac River for the Fort Folly First Nation, is even more blunt.
The program is trying to restore salmon to the Petitcodiac after a dam that blocked the river for decades was removed a decade ago.
“The population would have gone extinct by now if not for the live gene bank program,” he said.
About gene bank program
The program started in 1999 when the returning population was estimated at 250 wild fish per year.
Salmon were removed from the Gaspereau and Stewiacke rivers in Nova Scotia and the Big Salmon River in New Brunswick to conserve its unique genetics and maintain the population until marine survival improved.
That hasn’t happened.
After the salmon went to sea, the report estimated only 0.05 per cent to 0.62 per cent survived to return to spawn.
In 2013, Fisheries and Oceans Canada believed just 37 adults returned in total, while in 2015 returns, the number was 205.
Trying to get the numbers back up
To increase marine survival, Robinson and others are intercepting salmon smolts leaving the Petitcodiac River and putting them in a wild salmon farm at Dark Harbour, Grand Manan, operated by Cooke Aquaculture.
“We raised them there with our partners till they mature to adults and we’re bringing them back and put them in the rivers to spawn and create a huge next generation,” he said.
“We’re trying to see if we can find a way to bring back numbers beyond what the live gene bank is capable of doing.”
The two hatcheries in the gene bank program are in Coldbrook, N.S., which holds the Gaspereau and Stewiacke population, and Mactaquac, N.B., which preserves the Big Salmon River population.
Every year, the program releases tens of thousands of fish back to their rivers of origin.
Surplus hatchery-raised fish are released into other inner Bay of Fundy rivers.
The report stated those rivers may contain remnant populations of Atlantic salmon.
www.cbc.ca 2020-05-16 09:00:00