By Tom Brough;
Whilst this strange ‘summer’ weather still limits some of our boat work in the more remote areas of Banks Peninsula, our research teams have been making the most of good weather windows and getting some solid work done.
We’ve been retrieving and redeploying devices called TPODs that are permanently moored around the Peninsula (see picture). At present we have 11 TPOD’s moored around the peninusla, from Birdlings Flat to Lyttelton and everywhere in between. We bought these around 10 years ago for the price of around $3,000 each.
These handy gadgets record the sounds of Hector’s dolphins and so can tell us about the locations on the Peninsula that the dolphins prefer.
Because dolphins make particular sounds called ‘buzzes’ when foraging, TPODs can also tell us how often dolphins are foraging in particular areas. The current deployment of TPODs has been in the water since September and have had to put up with two 10m+ swell events during the last month; causing no small about of anxiety to our researchers!
We have also been continuing out our routine photo-ID surveys of the Banks Peninsula coastline. Finding and photographing dolphins with natural marks in their dorsal fins allows us to keep tabs on the number of dolphin in the Banks Peninsula population. Occasionally, we can identify dolphins by slightly stranger means.
A dolphin we regularly see on the north side of the Peninsula, often following trawlers off Lyttelton Harbour. The dolphin is nicknamed ‘mouthy’ and for some reason seems to breathe through its mouth rather than its blowhole.
We recently published a paper on how this could occur; it being the first time this strange behaviour has been observed in the wild.
Understanding the dolphins’ habitat and the reasons they are found in particular places is one of our current research questions.
To answer this we deploy all kinds of scientific gizmos to tell us more about the areas the dolphins use more frequently.
This device (see picture), nicknamed Roberto, gives us a salinity and temperature profile of the water column as it is lowered to near the sea floor. Roberto also shows how much phytoplankton is in the water and measures dissolved oxygen. Having this kind of information allows us to understand and so better protect the important habitat of these special dolphins.
Fingers are crossed for better weather as we head into February when we will start looking at dolphin prey distribution, sediment sampling, and nutrient loads. Stay tuned!
Tom works for the New Zealand Whale and Dolphin Trust
The New Zealand Whale and Dolphin Trust was launched in 1992 by researchers Associate Professors Liz Slooten and Steve Dawson, along with Trust Patron Sir Geoffrey Palmer to foster research and effective conservation of whales and dolphins in New Zealand. The Trusts long-term goal is; “To enhance the current knowledge of behavioural ecology, distribution and genetic diversity of New Zealand’s whales and dolphins and help create informed management decisions”.
Follow their work @hectorsdolphin on twitter
or on Facebook @whaledolphintrust
Don’t forget we offer Akaroa Harbour Nature Cruises every single day of the year that is protected by a Hector’s dolphin sighting guarantee, or you can come and cruise again with us for free. We donate a portion of every single ticket sale back towards the eductaion and research of Hector’s dolphins.