Dolphin teeth to track pollution

UNIVERSITY of Otago researchers will use the teeth of bottlenose dolphins to better understand coastal contamination.

Metal exposure in marine species will be tracked by researchers to determine pollution in the ocean. Metal contaminants are absorbed into teeth and bones, posing a risk for both humans and animals.

As dolphins feed on fish, they are potentially susceptible to metals like lead or mercury — just as humans are and humans eat some of the same seafood as dolphins, Carolina Loch, of the faculty of dentistry, said.

‘‘Wastewater from mining and city pollution goes back into the marine environment and it comes back to us when we consume seafood,’’ Dr Loch said.

‘‘The idea is about using a species living in that environment with teeth that record contamination throughout the animal’s life.’’

Water or seaweed samples can reveal information about contaminants at a certain point in time, but the dolphin teeth enable the researchers to look at what happened in past times.

For example, researchers will look at whether there was any correlation to a reduction in pollution when leadedfuel bans for road vehicles came into effect in New Zealand in 1996.

Dr Loch expects that high concentrations of toxic metals in teeth will be correlated with increased industrial contamination, while decreased levels would be expected where environmental practices improved.