The Royal College museum has a large collection of teeth including samples of leopard seals, dating from the early 20th century. So the college was able and provide small samples of these to the New South Wales School of Biological, Earth and Environmental Sciences, who are studying how climate change has altered the diet of the Antarctic Peninsula top marine predators. The stable isotopes of nitrogen and carbon in teeth act as a marker for the diet of the animal, so changes in the diet can be assessed
The WEST COAST of the Antarctic Peninsula has been one of the most rapidly warming places on earth. The EAST COAST has remained reasonably stable. This warming has an effect on the Antarctic ecosystem. The leopard seal is amongst the top predators in this region, therefore, one of the first animals that might show a change in diet. Indeed this seems to have happened; on the west coast it appears the leopard seal is no longer top predator, it now eats krill (a krillavor!). Krill stocks are diminishing, so the future of leopard seals in this area is uncertain. At present the females are significantly smaller than they were thirty years ago. This change has not happened on the east coast. It is interesting to speculate if some leopard seals have changed their hunting areas to follow their preferred prey.
This interesting piece of research may be due to global warming. It would be interesting to know if killer whales, an efficient top predator, also shows evidence of dietary change.
Isobel Williams – Author, Cruise Speaker and Lecturer 