March 20th 2018
Update: Hector’s Health Surveys
Our new project is underway!
We have begun piloting a new technique which we will hope will teach us more about the health of our local Hector’s dolphins.
We are using a sampling technique never before attempted with this species known as ‘blow sampling’ to determine whether it can be used to detect infectious diseases.
This method has been used successfully in the past with orca, humpbacks and bottlenose dolphins, and requires us to capture the air and water expelled from the Hector’s blowhole (basically dolphin breath!).
We do this using a petri dish on the end of a long pole, and the samples are then labelled and sent away for analysis at the Institute of Veterinary, Animal and Biomedical Sciences at Massey University.
This project was prompted by the discovery of a new disease within our local Hector’s dolphin population.
In December 2016 a Hector’s dolphin that washed near Harnett’s Creek, Kaikōura, was found to have died from tuberculosis. The bacteria that causes this particular strain of tuberculosis, Mycrobacterium pinnipeddi, is common in fur seals in sea lions, and has been reported seven times in New Zealand beef cattle, but has never before been found in cetaceans (dolphins, whales and porpoises).
Read the Stuff article about this case here.
Hector’s are only found around New Zealand, and are already listed as endangered, so it is crucial that we understand how infectious diseases such as tuberculosis are making their way into our local dolphin populations.
One possibility is that human related pollution and pathogens can be washed into the ocean following heavy rains. This phenomenon is known to have caused the deaths of sea otters off the California coast. In this case the otters were found to be infected with a parasite called Toxoplasma gondii which comes from cat faeces.
We are hoping that blow sampling will allow us to detect the presence of this, and other, infections– a first step in determining where the problem is coming from and devising a strategy to better protect our dolphins from this new threat.
February 1st 2018
Update: Hector’s Dolphin Surveys
K.O.R.I is pleased to announce the successful completion of our first batch of boat-based surveys for 2018!
These surveys are part an ongoing study that began in 2013 which aims to record and monitor the critically endangered Hector’s dolphins found in the waters around Kaikōura.
Our survey routes alternate between the two sides of the Kaikōura Peninsula, taking us as far as the Hapuku River to the North, and the Haumuri Bluffs to the South. We note all the marine mammals we encounter (as well as any penguins!), and also record environmental data as we go.
We are happy to report that amongst a multitude of other species including dusky dolphins, common dolphins, New Zealand fur seals, little blue penguins and Hutton’s shearwaters, we have had numerous sightings of our main subject matter – the Hector’s dolphin.
Encountering Hector’s dolphins allows us not only to monitor their behaviour and habitat, but also helps us achieve the other main aim of our surveys – to add to our catalogue of recognisable individual Hector’s dolphins.
We use photo identification of the Hector’s dorsal fins in the hope of spotting distinctive markings to distinguish an individual from the group. This isn’t always easy, but the dolphins do help us out as they come close to the boat to play in the swell. The photographs we take then go into our catalogue to help build a picture of the populations we have here.
The surveys we have conducted so far have been possible due to generous funding from several groups – and K.O.R.I would like to thank the Encounter Foundation and The Department of Conservation for helping us carry out this important work.
The analysis of the data so far collected is ongoing, but we are already looking forward to getting back onto the water in March for the next batch of surveys!