Provincial wildlife officials are expected to finalize plans next month for the recovery of disappearing American Eel populations in the Ottawa River.
The species once accounted for more than 50 per cent of the biomass in the Ottawa River watershed. In the early 1900s, the river “ran silver” with estimated hundreds of thousands of the snake-like fish.
Sometimes, they were even a nuisance – jamming mill wheels because of their abundance, says David Browne, director of conservation at the Canadian Wildlife Federation.
This is a very different picture now, says Browne, who notes that a conservation team found only 37 eels above Arnprior during a recent study.
The eels are an elusive migratory species, making it difficult to track the total population.It migrates along the east coast of North America into freshwater tributaries from Ontario up to the Labrador coast.
It’s important to find ways to get them moving into upstream habitats, as well as migrating to sea, says Browne.
This could mean changing the turbine and intake hydro systems found along the Ottawa River or rerouting fish populations using fish ladders and diversion channels.
The goal is to bring migration levels back to those seen in the 1980s by 2070 and to cut mortality rates in half by 2050.
The American eel was listed as endangered under Ontario’s Endangered Species Act in 2008, but is still “under consideration” for a new classification at the federal level, says Fisheries and Oceans spokesman David Walters.
While no final decision has been made on the status of the species, “conservation and protection of species at risk remain a priority,” says Walters.
Throughout the Ottawa River watershed, there are more than 50 dams but no functioning structures to allow the fish to pass safely.
Many female eels migrating to the Sargasso Sea in the North Atlantic are killed by hydro turbines, according to a Ontario Ministry of Natural Resources proposed recovery strategy .
Making dams and hydro projects more passable for eels could also mean making them safer for other migratory aquatic species such as sturgeon and walleye, says Browne.
The first obstacle that eels meet is a dam at the mouth of the Ottawa River in Rigaud, Browne says. Parks Canada provides a fish passage through a lock, but it is not available throughout the year.
The federal fisheries department has been criticized for its “poor track-record on biodiversity,” says Meredith Brown, head of the Ottawa Riverkeeper advocacy group.
“For the number of species they’ve listed as endangered, they’ve hardly written recovery strategies and for those recovery strategies that they’ve made, they haven’t really implemented them.”
The species was reassessed by COSEWIC, a federal wildlife advisory committee, as threatened in May 2012, says Walters.
Co-operation between the federal government, hydro companies, aboriginal groups, conservationists and other provinces – specifically Quebec in the case of the eel – is integral to lowering fish mortality, Brown says.