Using western science and Inuit knowledge to model ship-source noise exposure for cetaceans (marine mammals) in Tallurutiup Imanga (Lancaster Sound), Nunavut, Canada

Abstract

Tallurutiup Imanga (TI) is a National Marine Conservation Area (NMCA) established in 2019 at the eastern entrance of the Northwest Passage in Lancaster Sound, Nunavut, Canada, to protect 110,000 square kilometres of core habitat for cetaceans. This study examines the potential impacts of underwater noise from increased ship traffic in TI NMCA on three cetaceans: narwhal, beluga whale, and bowhead whale. Automatic Identification System data from 2015 to 2018 were used to spatially analyse ship traffic in the area. Sound propagation loss was modelled using vessel positions along major routes and then used to model vessel acoustic noise outputs. Areas populated by narwhal, beluga and bowhead whales were identified using western science and Inuit knowledge and then overlapped with the vessel noise outputs. Results indicate that an increasing number of ships are transiting important habitat areas for cetaceans and that this has resulted in some areas where the National Oceanic and Atmospheric Association 120 dB behavioural threshold for marine mammals has been exceeded. This suggests that in some areas of TI NMCA ship noise may negatively impact marine mammal hearing and behaviour, with the highest potential exposures in Eclipse Sound and Milne Inlet.