TriOceans has spent 8 years curating a photoID catalogue for bottlenose dolphin in Far North Waters and can track how the population parameters evolve.
PhotoID (short for photo identification) is used by researchers to track bottlenose dolphin movements, social networks and habitat preferences. Each fin is unique like a human fingerprint, enabling individual movements to be tracked with minimal disturbance.
Markov chains are used to assess how the behaviour of marine mammals changes across a range of variables (depth, group size, presence of calves or vessels…). Results indicate bottlenose dolphins spend less time feeding and resting, but more time milling and socialising in the presence of vessels. This work follows from a Massey unviersity study conducted in 2016 – https://www.doc.govt.nz/globalassets/documents/conservation/marine-and-coastal/bottlenose-responses-dolphin-vessel-activity-northland.pdf
Did you know not all bottlenose dolphins are the same?
Two ecotypes can be found here: a coastal and a pelagic (or offshore) bottlenose dolphin. While not different enough to be classified as separate species, those two “groups” do not mix, and the TriOceans team even assisted in a study identifying they use slightly different whistles. So how can you tell the difference? Look for circular scarring along their flanks: these scars come from the cookie cutter shark (Isistius brasiliensis) and are only seen on the pelagic individuals. The pelagic ecotype remains widely unknown, however it does seem to be of a friendly nature: they are often seen in association with pilot whales or false killer whales. In fact, false killer whales in New Zealand have never been seen without pelagic bottlenose dolphins around! The video above was recorded during scientific research in Northland and shows the close association between 2 different species. Don’t forget to turn your sound on! Can you hear the difference between the 2 species?
Kernel density maps of little blue penguins in the Bay of Islands
The TriOceans team drives pre-planned transect lines to cover Far North waters evenly whilst searching for target species. This allows for reliable population and distribution estimates. Amongst those recorded are the little blue penguin, allowing us to build an 8 year database of their daytime movements.
Little blue penguins are found throughout Far North waters, yet they remain largely unstudied
TriOceans