'Dead Sea': Millions of themisto plankton rotting ashore in Paulatuk, N.W.T.

People in Paulatuk, pop. 300, are wondering why a mass amount of dead, cold-water plankton have washed up on their beach.

1st recorded incident in Beaufort Sea as far as community, experts know

A bag of themisto libellula collected for sampling by Kim Ruben early last week. (Diane Ruben)

A cold-water plankton species has washed up on the shores of Paulatuk, N.W.T. — dead, and in the millions.

The themisto libellula is a type of zooplankton — a close relative to shrimp — abundant in most Arctic and subarctic seas, including in the Beaufort Sea near Paulatuk. It's eaten by Arctic char and cod, as well as seals and birds, and grows to be about one centimetre long.

Two weeks ago, at least 10 kilometres worth of themisto libellula showed up on the shorelines of the hamlet of about 300. And now, they're rotting.

One of the themisto libellula found along the beach in Paulatuk, N.W.T., last week. Themisto are born at about one millimetre and can grow up to five centimetres. (Kim Ruben)

Diane Ruben, who's with the community's hunters' and trappers' group, says this is the first time she's seen such a large amount of dead themisto, adding that people in the community are collecting samples to see exactly why all the plankton washed ashore.

Kim Ruben, one of the community members who's helped collect samples, says the layer of plankton initially looked like maggots — and doesn't smell very good either.

It smells like "kind of rotten seafood when you're driving around," Ruben said.

'Pretty unusual'

Louis Fortier, a professor at l'Université Laval in Quebec and an expert in Arctic zooplankton, says it's hard to say exactly what caused the themisto to wash ashore like this.

But he says it could likely be because of near-perfect wind conditions and very specific timing; if the themisto were feeding near the surface of the water while high winds gusted through the community.

"That's why this is pretty unusual," he said.

Two weeks ago, winds gusted 60 to 90 kilometres an hour near Paulatuk and Tuktoyaktuk, N.W.T., nearly pulling an abandoned building away from the coast. Fortier says those high winds could have played a major factor.

Lois Harwood, a biologist with the Department of Fisheries and Oceans, says her recent research shows there is one precedent to this incident, which happened in 2001 in Svalbard, an archipelago island between Norway and the North Pole. She says there's no record of this happening in the Beaufort.

'Bear with them'

Despite their off-putting smell, Fortier says the dead themisto shouldn't disrupt the ecosystem, and that the millions that washed ashore in Paulatuk are a fraction of the full population.

He says they'll likely "feed the sea birds for a while with abundant food" — which might be the only way to get rid of the rotting themisto.

Diane Ruben, who's with Paulatuk's hunters' and trappers' organization, says the dead themisto start on the community's beach and then stretch at least 10 kilometres to Argo Bay beach. (Google)

"The best thing would be to try and throw them back in the ocean, I guess," Fortier said. "Otherwise they'll just have to bear with them and the birds will probably feed on them."

Kim Ruben isn't sure what the community is going to do with them, but she hopes something is done soon.

"It's pretty [much] like 'Dead Sea,'" she said.