24 Oct 2012 08:02AM
ST. ANDREWS – If you were not there Aug. 15, you missed this year’s salmon run up the Magaguadavic River.
On that date, a 78-centimetre multi sea winter female wild Atlantic salmon came back from the ocean to the fish ladder at the hydroelectric dam crossing the river at St. George, according to the Atlantic Salmon Federation.
“One,” Jonathan Carr in St. Andrews, the federation’s research and environment director, said. “Only one wild fish came back to the river this year,” a discouraging result after a decade of restocking.
In the 1980s as many as 1,000 salmon returned to the Magaguadavic River each year.
The Department of Fisheries and Oceans began “live gene banking” Magaguadavic salmon at the Mactaquac fish hatchery in 1998. Restocking began in 2002.
In 2007, Cooke Aquaculture provided space, material, expertise and in-kind help at its hatchery at Thomaston Corner on the Magaguadavic itself. Salmon for stocking the Magaguadavic now comes from this hatchery.
Salmon escaped from fish farms outnumber the wild fish coming up the Magauadavic every year – 19 and counting in 2012, Carr said.
Wild fish returning to spawn dropped to two in 2004 but reached six in 2009, 12 in 2010 and 18 last year.
Then, one this year.
“It’s not surprising because all the other local rivers have dropped,” Carr said. “The St. John was terrible this year.”
Up until Oct. 1, only 84 grilse (salmon that return to spawn after one year at sea) and 104 MSW salmon (that spend two or more years at sea) came up the river to the Mactaquac Dam, according to figures the federation cited from Fisheries and Oceans. To the same date last year the numbers were 941 grilse and 624 MSW salmon at Mactaquac.
At the Nashwaak River counting fence, the numbers to Oct. 1 were 16 grilse and 38 MSW salmon, compared to 401 grilse and 230 MSW salmon to the same date last year, the federation reports.
Reports from the Miramichi River system, which drains into the Gulf of St. Lawrence, reflect the same trend.
To Oct. 14, a total of 206 grilse and 141 MSW salmon were counted at the Northwest Miramichi barrier, compared to 842 grilse and 265 MSW salmon to the same date last year, according to figures provided by the federation.
In the Dungarvon, a tributary of the Renous River which flows into the Main Southwest Miramichi, the numbers were 166 grilse and 128 MSW salmon to Oct. 14, compared to 633 grilse and 267 MSW salmon to the same date last year.
In the Magaguadavic River, exotic fish including smallmouth bass and, since 2003, chain pickerel, prey on juvenile salmon. But this does not explain the low numbers returning from the ocean, according to scientists and conservationists.
For every 100 smolt that go to sea in the spring, about seven should come back to spawn, Carr said. The numbers did not reach that this year, especially in the Magaguadavic.
Possible factors include collapse of other species such the northern cod, which seals and other creatures eat, and warmer water temperatures affecting what the salmon eat.
“So there is a whole suite of factors,” Carr said. “I’m saying that marine mortality is a big issue for us right now.”
In some Gulf of St. Lawrence rivers, scientists surgically insert two-centimetre sonic “pingers” in salmon, then deploy receivers to record what happens to individual fish, Carr said.
He does not give up on salmon in Charlotte County rivers. Monitoring, including electro-fishing surveys, still finds juvenile salmon in New, Pocologan and Digdeguash rivers and in Dennis Stream, Carr said.