Cod stocks in the southern Gulf of St. Lawrence, from the Gaspé to Cape Breton, have hit an all-time low, according to biologists from the federal Department of Fisheries and Oceans.

Moncton-based DFO biologist Doug Swain said only around 50,000 tonnes of cod are left in the area — about 15,000 less than the 65,000 tonnes in 1993, shortly after a moratorium on cod fishing was introduced across Atlantic Canada.

Swain said the latest numbers have him concerned about the cod's future.

"The last assessment, the estimate of the spawning stock biomass, is the lowest that's ever been observed in the 58-year record that we have," Swain said.

"Even if there's no fishing, the stock is likely to decline, so it's a very difficult situation."

In 2004, the federal government reopened a limited cod fishery in the Gulf of St. Lawrence following a 12-year moratorium on fishing across Atlantic Canada and Quebec. The remainder of the cod fishery was shut down in 2003.

But Swain said that slowly reproducing adult cod, not the limited fishing, have contributed most to the species' decline in the southern Gulf. Cod have not been reproducing quickly enough to counterbalance the number of fish that are dying, he said.

"According to our assessment … even if there's no fishery, the spawning stock's expected to decline next year," he said.

Scientists only have theories on why adult cod are not reproducing quickly enough, from predators such as seals to the possibility of genetic changes that encourage smaller, slower-growing fish.

As for the fishery's future, Swain said it is too soon to say what the federal fisheries minister will do with it in light of the latest numbers.

"That doesn't mean there will be no fishery, because there's other things to be taken into account in determining whether there will be a quota, and that's the economic and social considerations," he said.

"But from a biological perspective, there's very little extra production that can be fished without having the stock decline."