Canada: Seals aren’t mackerel’s biggest predator, according to a study by DFO and partners

CORNER BROOK, N.L. — While fingers are often pointed at seals for consuming more than their fair share of commercial fish species, a study on mackerel has shown other predators have likely been putting a bigger dent in the fish stock. The joint study was conducted by the Department of Fisheries and Oceans (DFO) Canada, the Northeast Fisheries Science Center based in Woods Hole, Mass., and Cégep de Rimouski in Quebec. It indicated that natural predation of Atlantic mackerel seems to be on the rise, but the array of predators is varied and the forage fish is considered a minor prey source for grey seals. Mackerel are also feasted on by northern gannets, spiny dogfish, bluefin tuna, white-sided dolphins, harbour porpoises and pilot whales. “A lot of harvesters were asking us about seals and were worried, so we started to wonder maybe there is more going on,” said Elisabeth van Beveren, a DFO biologist who co-authored the study. “What’s clear was other predators likely consume much ...