Scientists Predict Climate Change Winners & Losers in Antarctica

(CN) – Applying workplace safety parameters to marine Antarctic animals, scientists say they can now predict climate change winners and losers in the Southern Ocean.

In this Jan. 31, 2018, image supplied by Dr Regina Eisert of the University of Canterbury a minke whale floats to the surface through the ice in McMurdo Sound, Antarctica. (Regina Eisert/University of Canterbury via AP)

A British Antarctic Survey team sponsored the National Environmental Research Council utilized risk assessments normally applied in occupational settings and found mammals that depend on sea ice for food and breeding like humpback whales and emperor penguins will be at greater risk as temperatures rise and sea ice melts. The winners will be starfish and jellyfish and other animals who feed in open-water and along the seafloor as melting ice will open up new habitat.

“One of the strongest signals of climate change in the Western Antarctic is the loss of sea ice, receding glaciers and the break-up of ice shelves,” lead author Dr. Simon Morley said in a statement. “Climate change will affect shallow water first, challenging the animals who live in this habitat in the very near future. While we show that many Antarctic marine species will benefit from the opening up of new areas of sea floor as habitat, those associated with sea ice are very much at risk.”

As the amount of available climate change research grows, those reviewing it all need more novel approaches for honing in on which species would be most at risk. While knowledge has grown over the past 40 years gaps still remain, according to researchers.

“We took a similar approach to risk assessments used in the workplace, but rather than using occupational safety limits, we used information on the expected impacts of climate change on each animal,” seabird ecologist and study co-author Mike Dunn said in a statement.

“We assessed many different animal types to give an objective view of how biodiversity might fare under unprecedented change,” he said. These assessments make up part of a special article collection on aquatic habitat ecology and conservation.

Reviewers found a domino effect. They scored krill – crustaceans whose young feed on the algae growing under sea ice – as vulnerable. This in turn makes the animals who feed on krill likewise vulnerable. Krill eaters include Adelie and chinstrap penguins and the humpback whale.

Adelie penguins in Antarctica. (Photo by Jason Auch via Wikipedia Commons)

The emperor penguin is scored as high risk because climate change is already affecting sea ice and the ice shelves they require for breeding and raising their young.

This effect goes other way as well.

“The southern right whale feeds on a different plankton group, the copepods, which are associated with open water, so is likely to benefit,” Dunn said. “Salps and jellyfish, which are other open-water feeding animals are likely to benefit too.”

Starfish, sea urchins and worms – the bottom-feeders, scavengers and predators of the sea – will also likely benefit because they will have greater fodder as the vulnerable species die off.

“Many of these species are the more robust pioneers that have returned to the shallows after the end of the last glacial maximum, 20,000 years ago, when the ice-covered shelf started to melt and retreat,” co-author Dr. David Barnes said in a statement. “These pioneer species are likely to benefit from the opening of new habitats through loss of sea ice and the food this will provide.”

Barnes explained that while some species can find safe areas to ride out the changes some will be greatly altered.

“Even if, as predicted for the next century, conditions in these shallow-water habitats change beyond the limits of these species, they can retreat to deeper water as they did during the last glacial maxima. However, these shallow-water communities will be altered dramatically – temperature-sensitive animals with calcium shells were scored as the most at risk if this happens,” Barnes said.

Researchers are optimistic that as more information becomes available their predictions will improve. They are also planning how to weigh the gains and losses against each other to determine in which cases the benefits might outweigh the losses.

“The next step is to assign weights to the factors and predicted impacts. For example, temperature is a factor that has major effects on cold-blooded marine animals, but will it be more of a problem than the benefit from loss of sea ice? It is very difficult to know until we have more data,” Morely said.

The study was published Thursday in Frontiers in Marine Science.

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