Are Marlborough Sounds’ Hector’s dolphins genetically unique?

reproductively active, we’ve done that from dead animals washed ashore, and looked at the ages of teeth.

‘‘Sectioning teeth in much the same way you might look at rings in a tree,’’ van Helden said.

‘‘But now we’ve got new techniques that have been developed, and it’s very exciting because we’re just under way, and it allows us to start to look at the ages of animals simply by using tiny, little biopsy samples.’’

Van Helden said new research tools also allowed scientists to monitor what the dolphins were feeding on, which in turn could give the team an insight into the animals’ movements around the top of the south.

‘‘The research on their diets is pretty new.

It’s understanding their isotopic range, which will essentially tell us where they’re feeding and what sorts of species they’re feeding on.

‘‘This will help us through time as we try to navigate trying to understand the implication of things like climate change on the distribution of animals, and their associated diets. ‘‘So if there are changes in diet, whether their diet changes through time or whether they move in association with their diet and the movement of animals which they feed on,’’ van Helden said.

It was hoped the data collected would allow the team to see if the populations across the top of the south remained separate, or whether animals interacted, and moved between groups.

‘‘We have very little information about animals from Golden Bay and Tasman Bay, and whether they are related to either the animals on the top of the West Coast, Marlborough Sounds, or the animals in Cloudy Bay at the top of the East Coast.

‘‘Some of the questions to still ascertain are whether or not those Hector’s dolphins in the Marlborough Sounds are genetically different, or just an extension of the Cloudy Bay population and whether or not they’re in the Sounds all the time, or whether they move between those two populations.

‘‘Is there a cut-off point between the Marlborough Sounds and Tasman Bay for example? The animals in Golden Bay and Tasman Bay may be distinct from those in the Sounds. We don’t yet fully understand that,’’ van Helden said.

Van Helden said the more information his team had about the animals and how they lived, the better equipped they would be in managing and protecting them from potential threats, including toxoplasmosis, an infectious parasite that was predominantly spread through cats urine and could be catastrophic to dolphin populations.

‘‘We know that dolphins all around the country are susceptible to catching this, and dying from this disease, and that seems to be pretty significant,’’ van Helden said.

According to DOC, Maui (Cephalorhynchus hectori maui) and Hector’s (Cephalorhynchus hectori) dolphins were closely related and were two subspecies of the same dolphin species.

Ma¯ui dolphins were found only along the west coast of the North Island, and it was estimated there were only around 54 individuals remaining.

The Hector’s dolphin population was estimated to be about 15,000 and was classed as nationally vulnerable.

Van Helden said monitoring the dolphins’ movements, and