About 25 sealers arrived on Hay Island, N.S., off the eastern coast of Cape Breton, on Thursday for the start of the grey seal hunt.
Fisheries officers, veterinarians and anti-hunt activists are monitoring the hunt.
Journalists are on the tiny outcrop of rock to observe but are barred from approaching the sealers or getting within ten metres of the hunt.
Seals are reportedly scattered across the island, which is about one kilometre long.
This year, sealers tested small-calibre ammunition that was expected to cause the immediate death of seals and eliminate the risk of ricochet for sealer safety.
A representative of the Humane Society said the experiment is not working.
"We saw seals that were thrashing around after being shot that had to again be clubbed to finish them off. It's been a very difficult thing to watch," said Rebecca Aldworth.
But CBC video showed a seal being rendered lifeless after one shot from a hunter's rifle. Official reports from veterinarians observing the hunt are not yet available.
Hunters say they have secured two Newfoundland-based buyers for the meat. The Department of Fisheries and Oceans has set a quota for the island of 1,900 animals, down from 2,200 last year. The hunt did not take place last year because sealers said they could not find any markets.
The Hay Island hunt officially opened last Thursday, but sealers were delayed by bad weather over the weekend.