Concern over impact of sonar on whales as Russia plans naval exercises

Drills to take place off Irish coast pose threat to rare marine species, says Minister

Russian plans for naval exercises off the Irish coast have renewed concerns around the threat posed by military sonar to sea life including whales and rare marine species.

On Tuesday, Minister of State for Heritage Malcolm Noonan said he had set out his "deep concerns" in writing to the Russian ambassador and to the Minister for Foreign Affairs Simon Coveney.

“While we do not know the nature of these exercises, we do know that underwater sounds such as active military sonar can have devastating consequences for cetaceans including some of our rarest marine mammal species, notably the deep-diving and rarely-seen Blue whale, Sperm whale and beaked whales,” he said.

“It can cause significant disruption to their hearing systems and normal behaviour, and may lead to permanent or even lethal injury.”


Mr Noonan, who has long been involved in wildlife and natural conservation efforts, noted that Ireland’s marine mammal populations have been the subject of extensive research over the last three decades.

“Understanding of species occurrence, abundance and distribution has improved markedly in that time,” he said, singling out the recent ObSERVE project that mapped cetaceans through aerial and ship-based surveys over a three year period.

In 2008, the science journal Nature published a report it obtained from UK military which said whales subjected to sonar would neither dive nor feed.

“The impact of sonar on whales has become an increasingly fraught issue in recent years, with submarine exercises being linked to several high-profile mass strandings,” Nature reported.

“The US Navy has admitted concerns over sonar’s effects on marine mammals, although actual evidence for harm has been in short supply.”

Last February, the Royal Society in Britain published the latest "co-occurrence of beaked whale strandings and naval sonar" from islands in the west Pacific, and found "highly significant" links between the two.

Naval active sonar is linked to exceptional cetacean strandings in sources of ocean noise explored by Jonas, the research project co-ordinated from University College Cork.

In attempting to escape noise, stressed animals are thought to possibly alter their diving pattern, in doing so triggering physiological changes that lead to stranding.

In April, 2019, after a number of whales washed ashore in Ireland, experts speculated that they may have become confused while trying to swim away from underwater military sonar signals.

At the time, Sean O'Callaghan, science officer with the Irish Whale and Dolphin Group (IWGD), said research was ongoing to explore the possibility.

Mark Hilliard

Mark Hilliard

Mark Hilliard is a reporter with The Irish Times