Canada's largest seal cull for more than 50 years is taking place despite protests by environmentalists and animal rights groups.
Previous seal hunts have provoked international outrage
The government is allowing more than 300,000 seals to be killed, arguing that the campaign is both ecologically sound and economically justified.
Protests helped end the hunting of young seals for their pelts off Canada's east coast 25 years ago.
Some activists say their efforts to report this cull are being blocked.
Sealers have been making their way out to ice floes off the coast of Newfoundland and Labrador for the annual hunt.
Under new guidelines, most seals are meant to be shot and not clubbed to death in a bid to make the killing more humane.
Around 140,000 seals are expected to be slaughtered by the end of Tuesday.
The seal hunt in Newfoundland and Labrador withered 25 years ago as images of hunters clubbing infant seals horrified TV viewers across the world.
The US banned imports of seal products in 1972 and the EU followed suit a decade later with a ban on white pelt imports taken from the youngest babies.
Up to 350,000 baby harp seals to be killed this season
Preliminary culls started at the beginning of April
2,500 men and 150 trawlers to gather for intensive 36-hour phase of cull on 12 April
Up to 10,000 seals to be killed per daylight hour
Killing of "whitecoat" seals - aged up to 12 days - banned
As a result, the Canadian government reduced quotas for seal hunting to as low as 15,000 annually - mainly for meat and local handicraft. But with fur again in fashion, the hunt is back.
Canada increased the quotas last year, allowing a million seals to be killed over the space of three years.
Canadian Natural Resources Minister John Efford said many claims about the hunt were simply wrong.
He argued that the seal population was exploding - with an estimated 5.2 million harp seals in the North Atlantic at present - and commercial fish stocks were vanishing.
Mr Efford added that the cull was important for the local economy during a traditionally slow economic time of the year.
The Canadian tourism commission admitted last week it was keeping an eye open for an international backlash should the protests gather strength.
One campaigning group, the US-based Humane Society, has been taking full-page adverts in prominent American newspapers to urge a travel boycott against Canada.
Groups accuse officials of "attempting to scapegoat seals" for their own fisheries mismanagement.
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The International Fund for Animal Welfare (Ifaw) says government guidelines on humane hunting methods are being ignored.
"We filmed and witnessed seals being skinned alive right in front of us," Ifaw activist Rebecca Aldworth told Reuters news agency last week.
"We saw live seals being dragged while conscious across the ice with boat hooks; we saw stockpiles of dead and dying seals. It was really horrific."
The Ifaw also accused Canada's federal Department of Fisheries and Oceans of deliberately delaying the issue of ice floe permits to protesters wishing to witness the hunt.