What happens when you heat the Antarctic Sea by one degree?

One or two degrees might sound like a negligible change in temperature, and more often than not – in the oven, in the sauna, on your holiday in Crete – it is. But turn up the heat that much in the Antarctic Sea, and the results are altogether more stark.

According to researchers in Antarctica, increasing the temperature by one or two degrees on the seabed can have huge implications for polar marine ecosystems. The team, funded by the Natural Environment Research Council, published a study in Current Biology detailing the staggering effects galvanised by the ostensibly marginal temperature change, in a feat dubbed “the most realistic ocean warming experiment to date”.

When researchers heated an area of seabed by one degree, a single species of bryozoan (Fenestrulina rugula) began breeding like mad. Proliferation was so speedy that the species grew to dominate the community, causing biodiversity in the locality to plummet in under two months. Another unforeseen effect was that a certain species of marine worm – Romanchella perrieri, for those in the know – grew to 170% of its usual size. Unhealthy growth seemed to characterise the environmental changes elicited by a one degree temperature increase.

Results when the one degree increase was bumped up to two degrees, however, showed slightly more variation. Rate of growth in response to temperature varied according to species, age and seasons, with growth rates spiking in the Antarctic summer.

The findings have predictably gloomy implications for the future of global warming, with scientists warning that climate change could have a bigger impact on polar marine ecosystems that hitherto recognised. Gail Ashton, of the British Antarctic Survey and Smithsonian Environmental Research Center, was left reeling by the findings: “I wasn’t expecting a significant observable difference in communities warmed by just 1°C in the Antarctic,” she lamented. “I have spent most of my career working in temperate climates where communities experience much greater temperature fluctuations and wasn’t expecting such a response to just 1°C of change.”

If we don’t get our act together climate-wise, the Antarctic Sea and its various polar counterparts could become a hotbed of natural homogeneity, with biodiversity flattened due to incremental temperature rise – the word ‘hotbed’ used, harrowingly, in the most literal of ways.