Sea warming threat to native marine species

FOUR out of five marine species living in the oceans around Antarctica are expected to decline in number as the seafloor warms over the next century.

A British Antarctic Survey (BAS) team examined the potential distribution of more than 900 species of Southern Ocean shelf-dwelling marine invertebrates under a warming scenario produced by computer models.

The researchers concluded that, while some species in some areas will benefit, four out of five of the species native to the region (79 per cent) will lose out.

They said their findings, published in the journal Nature Climate Change, have “important implications” for future resource management in the region.

An average warming of 0.4 of a degree is predicted by 2099, and while the warming will not be enough to allow any species from other neighbouring continents to invade or colonise Antarctica, it will cause the unique local species to change their distribution.

More animals will lose suitable habitat than will gain it, with those animals especially adapted to the coldest water on Earth – for example in the Weddell and Ross Sea – losing out the most.

Areas of the West Antarctic Peninsula may become too warm for many native species, according to the study. The seafloor animals of the Southern Ocean shelf have long been isolated by the deep ocean surrounding Antarctica and the Antarctic Circumpolar Current, with little scope for southward migration, according to the research team.

Study lead author Doctor Huw Griffiths, a marine biologist, said: “While a few species might thrive at least during the early decades of warming, the future for a whole range of invertebrates from starfish to corals is bleak.”