Where I live, we long to see the whale-watcher’s dream species breaching, waving fins and slapping the water surface with its huge tail. I saw them do so off the Galapagos some years ago, an unforgettable experience. Complex songs, up to half an hour long, rival those of birds.
Changing slightly from year to year, they can be heard tens of kilometres away. Uniquely among baleen whales, humpbacks may hunt co-operatively; several will encircle a shoal, creating a virtual net of air bubbles to trap the fish inside. Humpbacks are so unique among the other great whales that they are placed in a sub-family of their own.
The chances of seeing humpbacks in the Irish Sea are slim but that may be about to change; numbers are steadily increasing in the Atlantic and there might be a ‘spill-over’ effect. A sighting off Howth in July 2010 was the first there in 20 years. ‘One swallow does not a summer make’ but a report from Liverpool raises a further glimmer of hope.
The Irish Sea has an image problem; surrounded by heavily populated landmasses and huge polluting cities, it lacks the romance and wild pristine glamour of the north Atlantic. Our east coast has few dramatic cliffs buffeted by fearsome waves. Discharges from Sellafield and the routine dumping of sewage sludge, not Spanish Armada wrecks, are the stuff of Irish Sea history. On ferry crossings, as recently as the 1970s, crew members would throw bags of rubbish overboard. Such practices are outlawed nowadays but flotsam and jetsam are still much in evidence. Porpoises and dolphins visit but the great baleen whales give the Irish Sea a miss. Sightings are mentioned occasionally in the press.
The appearance of a humpback whale in Liverpool Bay on June 9 caused a local media stir. Mobile phone footage, taken by one of the boatmen who spotted the visitor, appears on the web. Humpbacks have pectoral fins as big as light-aircraft wings. Lying on its side, a whale will wave one in the air; the web-footage shows the Liverpool visitor doing so.
According to the Sea Watch Foundation, dolphins and porpoises are frequenting the Liverpool Bay area in greater numbers, probably as a result of improvements in water quality. The arrival of a humpback, however, is ‘special’. Not since 1938 has one been seen in the bay. The most recent sighting previous to that was in 1863.
READ MORE: VIDEO: Humpback whale swims with paddleboarders in Cork .
Humpbacks spend the summer months feeding in food-rich waters close to the polar icecap. It’s too cold there for babies, so the whales head south to equatorial waters to give birth, mate and see out the winter. Their route brings them close to our west coast. The Irish Sea, being virtually an enclosed lagoon, is bypassed, which is why east coast sightings are rare.
Studying the humpback whale’s genome, Dr Kristen Ruegg and a team from Stanford University estimated there were between 45,000 and 235,000 individuals worldwide before the whaling industry targeted the species. The whalers, with steam-powered ships and explosive harpoons, killed mainly blue fin and right whales during the 19th century.
When the numbers of these species crashed due to the carnage, the whalers turned on the humpbacks, reducing their population by 90%. Only a few hundred remained in the north Atlantic when a moratorium was introduced in 1955. Since then, numbers have risen slowly. It’s thought that about 17,000 individuals roam the world’s oceans today.
Until recently, humpbacks were just occasional visitors to Irish coasts. Only six were landed at the Co Mayo whaling stations between 1908 and 1914 and, when whaling resumed there between 1920 and 1922, no humpbacks were caught. However, they are turning up now in increasing numbers off our west and south coasts. Singing and breaching have been recorded. Some whales may even be resident.