“We’re getting some genetic samples from the fish. So we’ll actually be able, in years to come, to look back and compare to see if there were any interactions between the farmed salmon and the wild salmon,” said Miranda Squires.
“We’ll be able to look at the genetics and the numbers to see if they are going down, if they are going up.”
The V-shaped fence spans a tranquil pool in the Come By Chance River, about two kilometres upstream from Placentia Bay.
At its centre is an underwater trap where fish are stopped, counted, sampled and then released to continue spawning upstream.
The location was chosen by both environmental consulting companies and the federal fisheries department, based on where Grieg’s sea cages will be in Placentia Bay.
Grieg is required to build and operate the fence following an environmental assessment of the company’s plans. The company says the fence is part of the company’s environmental effects monitoring plan.
Grieg says the fence it constructed earlier this year will cost $205,000 to build and operate in 2021.
By the end of August, 76 salmon were counted at the fence, but that number is reported by DFO with an asterisk as a partial count, because the fence was removed during part of the season.
Grieg officials say the fence on the Come By Chance River was knocked over fallowing a heavy rainfall in August. They say many fish were holding in a pool below the fence before the washout and it’s believed those salmon may have moved upstream before the fence was reconstructed.
Squires is optimistic the fence, which is expected to operate for a minimum of 10 years, will gather good data.
DFO’s Atlantic salmon recreational fishery statistics for 2012 to 2016 shows 927 salmon were caught in the Come By Chance River by recreational fishers during that period.
Grieg’s transfer to sea cages delayed
Grieg was scheduled to transfer immature salmon, produced in its land-based facilities, to sea cages in Placentia Bay this summer.
However the company delayed that plan and culled a million fish after infectious salmon anemia (ISA) was found in one of the fish scheduled to be placed in a sea cage this summer.
A further 295 fish samples showed no other incidents of ISA, a virus that scientists say can be fatal to both farmed and wild salmon but doesn’t harm humans.
“We had a suspected case of ISA but Grieg Seafood’s main focus is sustainability. We could have put the fish out if we wanted to, but we didn’t want to take any risks,” said Squires.
“Our mandate is to do as little damage to the environment as possible. So, we thought our best course of action is to put fish out in 2022, when we do more testing and we know that everything is good to go.”
Grieg says it’s on track to transfer about three million fish to the sea in the summer of 2022. Harvesting is expected to take place in 2023 and 2024.
The company expects to build a second counting fence in the Bay de l’Eau River in 2023, near its expected farming site in Rushoon.