ASF Rivernotes 6 Nov 2020

This will be our last regular River Notes blog for 2020, a year no one will forget. Amongst the raging headlines about the pandemics and elections, wild Atlantic salmon had a relatively good year.

Something went better at sea this winter and spring. It seems more salmon survived, perhaps a combination of improved environmental conditions and a reduced total harvest at Greenland thanks to the conservation agreement between ASF, the North Atlantic Salmon Fund, and Greenland commercial fishermen.

DFO, U.S., and Quebec scientists will now begin the process of collecting data from trap nets and counting facilities, analyzing the numbers, and estimating total returns. That will take some time, but the true test of the strength of this year’s returns comes five years from now, when the first of the eggs laid in rivers this month and last will return from the sea as adults.

At Rocky Brook, a phenomenal tributary of the Southwest Miramichi, a recent redd count found four times more salmon egg nests than in recent years, and the highest total number since 2001.

On the Sandy River, a tributary of the Kennebec in Maine, the redd count was also substantial this year, considering there were only 51 salmon trapped and trucked from an impassable dam lower in the system.

So how do these fish find their way back home after at least a full winter spent in the North Atlantic?

Their partially driven by magnetic fields and an imprinted smell of their home river. Salmon have such strong receptors that individuals can detect a single drop of certain chemical in water equivalent to the volume of 10-Olympic sized swimming pools

Three unique life strategies developed over thousands of years act as an evolutionary safeguard for the species.

Multi-sea winter fish that spend two or more winters in the rich waters off west Greenland are like a Maritimer heading for Alberta, in better days perhaps, to work far from home for big reward.

Grilse, adult salmon that spend a single winter at sea, not travelling all the way to Greenland, are like the kid from Cape Breton moving to Halifax for a time – more resources, but a shorter distance to home.

The third life strategy, used by so-called precocious parr, is comparable to never leaving your home town. These tiny males but all their energy into becoming sexually mature, not growing large. They stay put in the stream where they were born and when larger adults are in the act, these sneaky parr dart in and add their genetic material to the mix.

It’s believed that precocious parr can fertilize up to 30 per cent of all eggs in some rivers, proof that life takes all kinds.

On Nov. 4, 2020, ASF’s Executive Director of U.S. Programs, John Burrows, joined staff from Maine’s Department of Marine Resources on the Sandy River searching for redds. A greater number than usual were observed, a positive sign for this high-quality habitat.

Miramichi
There is excellent news from Rocky Brook and Clearwater Brook, two tributaries of the the Southwest Miramichi.

At the end of October, a team from Rocky Brook Camp did a count on both streams and posted some impressive numbers. On Rocky Brook, 218 redds were counted, the highest figure since 2011, and on Clearwater there were 112, the best since 2008.

St. John River
The final 2020 numbers are in for salmon returning to the Mactaquac Dam, and sadly the spiral to anthropogenic extirpation on this once great river continues.

Their were 146 large salmon this year compared to 192 in 2019. For grilse, there 346 to Oct. 31, vs 507 to the same date in 2019.

Overall it may have been a good year for Atlantic salmon here in North America. Plus indications it was a good year in many European areas. Yet because of Covid-19 pandemic restrictions on researchers, the assessment is likely to be more difficult.

In the end we will need to have a greater degree of confidence that the Atlantic salmon themselves know what they are doing, and will be the stronger for it in 2021.