By Hollie London
3rd year student studying BSc (Hons) Ocean Science and Marine Conservation – University of Plymouth
As part of my dissertation research, I was lucky enough to have the opportunity to spend 3 months on-board “Voyager”, a responsible whale-watching vessel based in Baltimore, West Cork, Ireland. I worked alongside Dr Nicholas Slocum from Whale Watch West Cork, mapping the distribution of cetaceans in local coastal waters. During the summer months, Irish waters become home to a range of feeding cetaceans, including odontocetes (toothed whales) such as short-beaked common dolphin and mysticetes (baleen whales) such as fin whales and minke whales.
One part of my research involved the photo-identification of minke whales – something that had not been attempted in Irish waters previously. Photo-identification uses photography to document unique markings such as dorsal or tail (fluke) shape, pigmentation patterns, deformities and rake marks (tooth marks from other cetaceans), to identify individual cetaceans in the same way humans can be identified by fingerprints. During my time in West Cork, I was able to identify 8 individual minke whales from both sides of their dorsal fin, with 2 repeat sightings.
Another part of my research was recording water properties such as the temperature and salinity of the water during cetacean sightings. Different water masses will have different temperatures or salinity, meaning they do not mix together. At the boundaries between these water masses, a process can occur known as upwelling. Upwelling can bring nutrients to the surface of the water, leading to plankton growth and the aggregation of prey. By understanding where these nutrients ‘hotspots’ are, it can help us to understand how cetaceans use West Cork for foraging and feeding. This can provide evidence for the implementation of conservation and protection strategies where necessary.