A breakthrough study by a specialist European research team shows that man-made underwater noise pollution is picked up by whales in a similar way they sense natural predators.
The report was led by a team of behavioral ecology experts including Professor Patrick Miller. While some cetaceans may be able to fight or flee from predators when they think they are under attack, underwater noise disturbance created by humans is also causing them to stop and become more vulnerable by impacting their energy budgets.
The findings were part of a project involving European colleagues.
The S3 research team found that navy sonar causes the cessation of feeding in all four species of whales, which all rely on acoustic signals to assess their risk of extinction.
The public became aware of the fact that whales and dolphins can be negatively affected by sound when large numbers of whales strand in association with each other.
In the early-to-mid 2000s, several different research groups, including our 3S group which authored this most recent work, established novel procedures to study how the behavior of free-ranging whales is affected by exposure to sonar sounds.
The team has documented the behavioral responses of six species of cetaceans off the cost of Norway, while other species have been studied by research groups in the U.S.
He explained that the data for the latest study was obtained in the waters around Norway and shows that when marine mammals are tagged with temporary transmitters, the amount of time they spend in the water increases.
The data varies between species with beaked northern bottlenoses stopping for the entire time.
As human activities impact virtually every animal habitat on the planet, identifying species at risk from disturbance is a priority. There was a correlation between the reduction in feeding activities and the killer whale sounds.
According to our study, whales who are both predator and prey but rely on hearing to find food and detect dangers have not adjusted their threat response by learning to tell the difference between noise that does not represent a predator.
They are having to choose between life and dinner when they hear a threat in the sea. Humans and killer whales are able to access the waters of the north due to the melting sea ice. Crypsis and flight are used by several marine mammals to avoid falling victim to killer whales, and similar responses have been reported to ice-breaker noise and airguns used in oil and gas exploration. Our findings show that these marine mammals face a double blow from increased number of real predator as well as increased human noise under the sea.
More information: Patrick J. O. Miller et al, Behavioral responses to predatory sounds predict sensitivity of cetaceans to anthropogenic noise within a soundscape of fear, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2114932119 Journal information: Proceedings of the National Academy of Sciences Citation: Underwater noise pollution threat to marine life (2022, March 23) retrieved 23 March 2022 from https://phys.org/news/2022-03-underwater-noise-pollution-threat-marine.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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