Global warming may make it difficult for Antarctica's cold-blooded animals to survive, leading to an upset in ecological balance, warn scientists.
Compared to their temperate and tropical cousins, cold-blooded polar marine animals are incapable of fast growth.
Until now scientists had assumed that a lack of food in winter was the major limiting factor.
But now, studies of the protein-making abilities of limpets in both the sea around the British Antarctic Survey's (BAS) Rothera Research Station and in the laboratory aquarium has shown that these animals cannot make proteins - the building blocks of growth - efficiently.
Growth in animals occurs primarily by making and retaining proteins. But, while the tropical water limpets typically retain 70 percent of the proteins they make, those in the Antarctic appear only to retain about 20 percent.
According to lead author Dr Keiron Fraser from BAS, the findings are an important step in understanding the complex biodiversity of Antarctica's unique ecosystem.
"Sea temperature is predicted to increase by around 2°C in the next 100 years. If cold-blooded Antarctic animals can't grow efficiently, or increase their growth rates, they are unlikely to be able to cope in warmer water, or compete with species that will inevitably move into the region as temperatures rise," said Dr Keiron.