Observing whale behaviour above the surface is an often-effective way of assessing the response to disturbance. However, to truly understand the influence of vessels and other humans activities on the lives of whales, you have to dive beneath the surface.
Cetaceans rely heavily on sound for communication, feeding and even navigation. Many species literally ‘see’ their environment in sound. As a result, loud human activities can disrupt this key sensory system, impeding their hearing, voice and ‘sight’. Vessels are no exception, with noise from the engine and cavitation (exploding bubbles caused by propeller rotation) contributing to an altered underwater soundscape.
As a result, characterising this soundscape is key to understanding the influence of vessels on whale populations. We deployed our first hydrophone (underwater microphones) in 2020 in Skjálfandi Bay, our whale-watching area, to do just that. We also hope to listen to whale vocalisations and, if possible, relate changes in vocalisation (rate, frequency and sound level) to variation in vessel traffic. The team doesn’t have much experience in acoustic research, so we’re extremely fortunate to work with Dr Michelle Fournet, a bioacoustics researcher from Cornell University, who currently supervises our fieldwork and data analysis. .
COVID-19 UPDATE: In these trying times, Covid-19 has provided a unique opportunity to listen to a quieter Skjálfandi Bay – by halting whale-watching activities and reducing vessel traffic generally. We worked with our local collaborators at University of Iceland to deploy a hydrophone to characterise this altered landscape and its consequences for whales.