The low number of white hake and Atlantic cod has led to the recommendation they be given endangered status by the Committee on the Status of Endangered Wildlife in Canada.
Nearly half a million grey seals in the Northwest Atlantic that feed on the fish are the main cause behind the recommendation, according to the committee.
It's also a combination of two other factors, said Hugues Benoit, head of the marines fish section at Fisheries and Oceans Canada.
"The available information we have now it does suggest that the combined effect of the low level of abundance of these fish species and high level of abundance of grey seals could be the cause of elevated natural mortality," he said.
Benoit suggests that seals are a "generalist" species — they eat what's available to them. If the population of hake and cod are scarce, seals move on to any other available species.
The decline of fish populations and the possible declaration of some species as endangered are leaving fisherman with limited options.
"They [fisherman] respect the rules even though it's a frustrating to be following rules," said Christian Brun, executive director of the Maritime Fishermen's Union.
"They feel it's a challenge to participate and establish an equilibrium and balance in these fisheries."
Brun said the seals will often interfere with fisherman by eating fish caught in the nets which leads to reduced harvest numbers.
Seal cull: is it the answer?
In 2012, the Senate's fisheries committee announced a plan to cull 70,000 seals to save the cod population. The committee's report also also recommended setting up a bounty system to compensate hunters.
The plan was criticized by some, including a group of marine biologists at Dalhousie University who claimed the seal population wasn't solely responsible for the decline in cod.
The culling of the seals was reconsidered several times, but never approved.
Hunting for seals is open, but there is a decline in the market due to the ban on seal products by the European Union.
An earlier version of this story indicated there are nearly half million grey seals in the Northumberland Strait. In fact, that's the number of grey seals in the entire Northwest Atlantic.Mar 15, 2016 10:35 AM AT