This week I started a new project. I'm working with a professor of mine compiling one large folder of photo identifications of dusky dolphins (specifically, a population off the east coast of New Zealand) from three different studies that span over 30 years! This is the longest study of this species of dusky dolphin in the world! I simply go one by one, using the Finscan program to identify if a specific dolphin's fin matches any other images from the other folders. We use things like notches and scars a dolphin's fin might have to identify them. Dolphins' fins do not grow back, so a notch that one had in a photo in 1984 will have that same notch in 2007. They could have more notches or scars, but once they are aquired, they are permanent.
I'm still not quite sure exactly what area of marine biology I am completely interested in, so I like this project because it gives me a good idea what being a marine mammologist might entail. When I learn something new, I also tend to think of new questions that gets me interested in what I am doing. A question that I asked was "how do these dolphins get these distinctive marks?" A colleague of my professor recently published a research paper just on that subject using these same photos I am helping identify. It turns out, most of the small marks the dolphins aquire are from interactions between the dolphins. Most of the larger, nastier looking marks most likely come from human interactions gone wrong. They even addressed the possibility of marks coming from predators, but very few are likely from their most known predator, the killer whale. The thought concluded is that the killer whales are very efficient with snagging their prey, so very few live to show the scar. The photo above, is not a photo I took, but yet a visual for the dolphin type I am working with. These are a very small dolphin species that is naturally seen throughout New Zealand and throughout Southern Australia.