Research project gets underway off the Welsh coast to monitor impact of noise on marine mammals.

Hi-tech recording equipment has been deployed off the coast of Anglesey to help scientists monitor the impact of underwater noise on dolphins and porpoises.

Working in partnership, Natural Resources Wales (NRW), the Centre for Environment, Fisheries and Aquaculture Science and Bangor University have placed specialist recording equipment at three locations in the North Anglesey Special Area of Conservation to learn if human made and natural noise affects marine mammals.

As part of the Welsh Acoustic Marine Mammal Survey, recordings will be made between 30 and 60 metres underwater over an 18-month period to understand how mammals like harbour porpoise, bottlenose dolphin, Risso’s dolphin and common dolphin, use the area.

During the project the audio equipment will be recovered every three months and recordings analysed.

Natural noise includes strong tidal flows carrying sediment, wind and rain on the surface of the sea, waves, and other marine life, while noise from human sources includes ships and boats, sonar, and the construction and operation of marine industries.

This project has received a grant from the Nature Networks Fund which is funded by the Welsh Government and delivered by The National Lottery Heritage Fund in partnership with NRW to help tackle the nature and climate emergencies.

Understanding

Alex Zalewski, NRW’s Marine Ecology Advisor for the project, said: “Underwater noise can disturb marine mammals and mask their ability to use and hear sound to find food and communicate with each other.

“We want to improve our understanding of how background noise levels impact these mammals by using specialised acoustic recording equipment.

“Understanding ambient underwater noise levels will give us more information about the distribution of noise, its sources and identify effective management options to help build resilience in populations of marine mammals.

“The recording devices capture sound within certain frequencies allowing us to detect the clicks and whistles dolphins and porpoises make. We suspect the underwater soundscape will be naturally quite noisy from strong tidal flows and there is likely to be detectable noise from human sources too.

“At the end of the project we will have a better understanding of how to monitor underwater noise in locations that are naturally noisy, allowing us to study how best to acoustically monitor porpoises and dolphins in Wales.”