The dismay stands out as undersea cameraman Ken O’Sullivan describes his enduring relationship with dolphins that inhabit the seas off Ireland, the subject of an upcoming two-part RTÉ television documentary.
His understanding of their lifestyle and how they interact with their surroundings is profound, and yet our lack of understanding of why so many common dolphins are being washed up dead on Irish coastlines troubles him.
At the very least, the State should be doing its part by investigating fully what is driving the deaths of so many, he says.
There are an estimated 30,000 common dolphins in Irish waters, he says. They are coming to inshore waters like never before, probably because of overfishing out to sea by factory ships and large trawlers, and climate change, which is warming waters.
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Up to 300 dead dolphins are recorded here every year. But French research suggests many more die at sea, and this could mean mortalities are in reality eight times that figure, he says.
“That’s up to 2,500 dying [in Irish waters] every year and nothing is being done,” says O’Sullivan. “No postmortems are carried out, which is standard in France. We have been losing thousands per year since 2011-2013.
“The data needs to be collected,” adds O’Sullivan, who says some research on this was done in the past but discontinued.
All told, he believes the combination of ocean noise pollution; deaths due to fisheries; and warming ocean waters present an existential threat to dolphins in the northeast Atlantic.
The documentary, Dolphins – Wonders of the Oceans, was made over the course of 20 years. “That’s a bit of a record, even for natural history”, he says.
O’Sullivan’s remarkable insight into dolphins, reflected in awe-inspiring footage that often matches the output of the team around famous naturalist David Attenborough, followed a free-diving encounter with a lone dolphin at a remote location near his home place.
“It begins in 2005 when I was becoming an underwater cameraman and I encountered a lone last dolphin off the Clare coast,” he says.
She was named Dusty, in honour of Dusty Springfield, whose ashes were scattered nearby off the Cliffs of Moher, her favourite place in Ireland.
“She became my subject for a time and was somewhat of a springboard for me to go out into open ocean to seek other dolphin species and whales – and ultimately to journey to the middle of the North Atlantic filming enormous dolphin pods and the largest animals to have lived, blue whales,” O’Sullivan says.
His journey charts their relationships with one another, their increasing vulnerability and his much-changed interactions with Dusty, who is still alive.
He admits he was part of a generation that grew up with the Flipper television series and The Big Blue film, regarding dolphins as playful and cute, and tolerating their confinement in amusement parks.
But all too often, the more he observed people patting and playing with dolphins, it “did not feel right”.
False trust may not be the best for wild animals. They can become violent, attacking if feeling threatened. “Maybe we should let wild animals be wild; the pursuit of beauty in nature means we should leave them alone,” he says.
When dolphins are over-boisterous, there is a need to keep calm and to maintain eye contact, he says, especially when you don’t know if this is play or something more sinister.
If Dusty comes up to him now, “that’s fine; we are keeping a respectful distance”.
O’Sullivan’s work on how dolphins communicate and how they collaborate in the constant search for fish makes for fascinating sequences. His discovery of a large pod of 100 common dolphins in the mid-Atlantic is illustrated spectacularly as they encircle a shoal (probably skad mackerel), working together to create a “bait ball” that is forced to the surface.
The cold water of the North Atlantic, compared with the clear blue water of the tropics, can prove to be more productive “if you have patience”, while drone technology is brilliant for observation though “it’s underwater where you really experience these animals”.
Their world is an acoustic one, where sound is their primary sense using echolocation. They emit calls and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify objects.
They whistle to each other; so the loud sounds of fast-moving ships can be a gross interference in their lifestyle – as he demonstrated with recordings at Dublin Port; a threat that could be easily mitigated by vessels slowing down at sensitive locations, he says.
O’Sullivan also demonstrates how dolphins have variation in the frequencies of their sounds, almost as if they have different accents. This may be linked to where they come from, though they can migrate long distances and inhabit places for extended periods.
There were between 150 and 200 bottlenose dolphins in the Shannon Estuary for decades - then many went farther south off Kerry. Yet another mystery about these special marine mammals to be resolved.
Dolphins – Wonders of the Oceans made by Sea Fever Productions will be broadcast on RTÉ One on Sunday, August 31st (6.30pm) – with Part 2 on Sunday, September 7th at the same time
