Analyzing Climate Change Through Shark Teeth

Photo Credit: Florida Museum of National History

During the Eocene epoch, 53 to 38 million years ago, the Arctic had a experienced a radically different climate than it does today. Instead of an icy tundra, the Arctic supported a temperate forest with brackish water. Now, shark teeth taken from a coastal Arctic Ocean site provides a rare set of marine records that could help us understand what effects current climate change may have on the Arctic's ecosystem.

Currently, the Arctic is experiencing a temperature increase that is twice the global rate and rising sea temperatures may lead to decreases in salinity levels (due to ice melt) which could cause problems for some animals living in the region. Shark teeth can provide insight into past climates of the Arctic, such as the warmer saltier Eocene epoch, because sharks are constantly exchanging water with their environment and therefore the isotopic oxygen ratio found in their teeth is directly correlated to the waters temperature and salinity. They found that during the warmer periods sand tiger sharks, which usually prefer areas of high salinity, were hanging out in brackish to freshwater. These findings suggest that certain sharks may be able to cope with salinity changes due to global warming.

Read the full article here: Shark Teeth Analysis Provides Detailed New Look at Arctic Climate Change