After our 2019 field season, we had many humpback whales fluke pictures to look through from Skjálfandi Bay. As we organized them into our ID catalogue, some diatoms caught our eye. Diatoms are single-celled algae that live in aquatic environments. Concentrations of phytoplankton including diatoms can be used as a measure of primary production in aquatic environments.

Some diatoms attach to whale skin. For humpback whales, diatoms can accumulate on the underside of their flukes, giving them an orange/yellow colouration. So we wondered whether there is something to be learned by looking at the diatoms on whale flukes. We are now exploring the feasibility of using diatom coverage on humpback whale flukes to monitor changes in in primary productivity in Skjálfandi Bay, Iceland.

Our progress so far:
So far we have organised all of the humpback whale flukes from three of our field seasons. We are now working to describe the quality and quantity of the diatoms for each fluke in order to compare them to the primary production in Skjálfandi Bay.