Whale 'superhighway' off the west coast of Ireland

A fin whale lunge feeding on sprat with common dolphins and Manx shearwaters in attendance off Union Hall, Co Cork. Picture: Tom Ormond

The waters off the west coast of Ireland are among the great "superhighways" of the world for migrating whales, a major new study on the travelling patterns of the various species has revealed.

A report from the World Wildlife Fund (WWF) and its partners has been described as the "first truly comprehensive look at whale migrations".

It analysed the "threats they face across all oceans, highlighting how the cumulative impacts from industrial fishing, ship strikes, pollution, habitat loss, and climate change are creating a hazardous and sometimes fatal obstacle course for the marine species".

According to the analysis, off the west coast of Ireland is one of the most important corridors for fin whales.

The WWF says the fin whale is an endangered species, with an estimated global population between 50,000 and 90,000.

"Next to the blue whale, the fin whale is the second-largest mammal in the world," the WWF's description of the mammal says. 

"They have a distinct ridge along their back behind the dorsal fin, which gives it the nickname razorback. 

Fin whales have a very unusual feature: the lower right jaw is bright white and the lower left jaw is black.

The fin whale has been severely impacted worldwide by commercial whaling, according to the WWF. 

"Nearly 750,000 animals were killed in areas of the Southern Hemisphere alone between 1904 and 1979, and they are rarely seen there today. Their current status is unknown in most areas outside of the North Atlantic," it says.

The coast of Ireland was one of a number of global corridors mapped out by the study, which used 30 years of scientific data from more than 50 research groups, as well as marine scientists from Oregon State University, the University of California Santa Cruz, the University of Southampton, and others.

'Next to the blue whale, the fin whale is the second-largest mammal in the world,' the WWF's description says. 

Entitled Protecting Blue Corridors, the study visualised the satellite tracks of 845 migratory whales worldwide, showing areas where they feed, mate, give birth, and nurse their young, but also where they face the greatest threats.

Chris Johnson, global lead for whale and dolphin conservation at WWF, said: "Cumulative impacts from human activities — including industrial fishing, ship strikes, chemical, plastic and noise pollution, habitat loss, and climate change — are creating a hazardous and sometimes fatal obstacle course.

 “The deadliest by far is entanglement in fishing gear — killing an estimated 300,000 whales, dolphins, and porpoises each year. What’s worse, this is happening from the Arctic to the Antarctic.”

Six out of the 13 great whale species are now classified as endangered or vulnerable by the International Union for Conservation of Nature, even after decades of protection after commercial whaling, the WWF said.

"Among those populations most at risk is the critically endangered North Atlantic right whale, a species that migrates between Canada and the US," the organisation said.

It is at its lowest point in 20 years — numbering only 336 individuals.

Some 86% of identified North Atlantic right whales are estimated to have been entangled in fishing gear at least once in their life, which the WWF described as "alarming".

"Just one death jeopardises this population’s survival. Between 2017 and 2021, 34 North Atlantic right whales died off the Canadian and US coasts from ship strikes and entanglement in fishing gear," it said.