B.C. Environment Ministry urges more protection for Haida Gwaii slugs

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A species of small slugs found only in Haida Gwaii off B.C.'s North Coast and a remote area of Vancouver Island are under threat from climate change and habitat destruction, according to a recent report.

In the report Management Plan for Haida Gwaii Slug in British Columbia published last month, researchers of B.C.'s Ministry of Environment and Climate Change Strategy says logging on Haida Gwaii's Graham Island and northern Moresby Island is also one of the major threats to Haida Gwaii slugs.

The tiny mollusks measuring eight to 17 millimetres in length could easily fit on a quarter. Their dark-coloured bodies are covered with small projections known as papillae.

The species was first documented in Haida Gwaii in 2002 and was classified as a species of special concern in Canada in 2013, meaning it is at risk of becoming threatened or endangered.

The report says other key risks to the Haida Gwaii slugs include extreme temperatures and increased storms and flooding as a result of climate change, and the Sitka black-tailed deer that humans introduced to the archipelago since the late 19th century.

As the deer browse on vegetation, they decrease the amount of plant litter on the ground, which deprives the slugs of cover and needed moisture. It can also expose the slugs to wind and sun.

Kristiina Ovaska, one of the biologists writing the report, says in 2002 that she discovered the Haida Gwaii slugs, which she describes as a unique species that can only be found in one other place on Earth: the Brooks Peninsula on northern Vancouver Island.

"It was quite an unusual looking creature," she told host Carolina de Ryk on CBC's Daybreak North. "It has a hump ... Any tiny little papillae or projections [are] on the mantle that covers the hump."

Ovaska says although some people may see slugs as pests in their house gardens, Haida Gwaii slugs play a very important role in the ecosystem.

"Small organisms that [are] small but mighty break down organic matter, and some of the slugs also disperse spores of mushrooms and little truffles that form intricate relationships with trees.

"We should keep in mind that they may be small, but they have millions of years of evolution," she said. "We don't fully understand what they do and what their functions are in the forest."

The B.C. Ministry of Environment's report recommends a list of measures to reduce threats to the Haida Gwaii slugs, including cutting the number of Sitka black-tailed deer in the slugs' habitat, and working with land managers to establish a habitat protection plan for the slugs.

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