VessEl noiSe effectS on balEen whaLe bioenergetics

ongoing

Baleen whales are mega predators that shape the ecosystem structure and maintain healthy marine environments. A decrease in their populations can therefore have cascading trophic impacts detrimental to marine ecosystems they inhabit. The marine soundscape has dramatically changed since the Industrial Revolution. With increasing traffic, ship noise has become the most ubiquitous and pervasive source of anthropogenic noise in the ocean. Baleen whales rely heavily on acoustic cues for interpreting and exploring the marine environment. However, they hear best and produce sound at the same frequencies where cargo ships make the most noise, which makes them potentially the most sensitive species to vessel noise disturbance. Numerous studies have documented short-term adverse effects on baleen whales exposed to vessel noise, including changes in behaviour, and decreases and/or cessations in foraging. However, there is a lack quantitative data on i) the specific noise levels that trigger changes in behaviour, and ii) how these noise-induced behavioural changes impact the fitness of the exposed individuals. Through VESSEL, I propose to fill these important knowledge gaps by applying an innovative combination of state-of-the-art tagging technology and noise analysis to, for the first time in baleen whales, i) quantify received noise levels on the animal, and ii) estimate a dose-response relationship between vessel noise levels and the energy budget of the exposed individuals. The outcomes of VESSEL will be crucial to parameterize Population Consequence of Disturbance (PCoD) models that link disturbance parameters to fitness and population dynamics. Importantly, VESSEL will be of direct relevance to the management of underwater noise levels in EU marine waters by providing evident-based estimates of critical noise thresholds for the fitness of baleen whales that will set thresholds for Good Environmental Status (GES).