Speaking from his home in County Clare, underwater cameraman Ken O'Sullivan remembers summers as a "young lad" spotting catshark and dogfish while fishing off the west coast of Ireland.
"My father used to curse them because they were a pain to get out of the nets," he said. "But when I started to see them underwater and how beautiful they were, the red series of bones and the way they moved so gracefully, I guess it was so different from what I'd seen dead and dying in fishing nets."
O'Sullivan's "seminal" encounter led to a two-decade career producing wildlife documentaries and documenting Ireland's 39 species of sharks. White sharks have so far remained elusive, "I've been trying to spot one for 20 years," O'Sullivan told ABC News. "I guess I got quite taken by them, physically and emotionally. But also, you don't have to read very much to understand the trouble that they're in."
This fall, American research group Ocearch has teamed up with 15 Irish shark scientists hoping to tag the first-ever white shark in Irish waters. The M/V OCEARCH will sail from Bantry Bay on Sept. 2, beginning the Ireland leg of Expedition Save the Med, a trip that hopes to shed light on the little known, but critically endangered white shark population in Spain, France and, hopefully, Ireland.
"Whether there are White Sharks around the British Isles has been a long-contested question," said Ali Hood, director of conservation at the Shark Trust.
"Conditions in parts of the United Kingdom and Ireland are very similar, to where there are thriving populations of great whites in other parts of the world. I'm talking about food sources -- namely seals -- and water temperatures," conservationist Richard Peirce told ABC News.
The preferred water temperature for white sharks is between 50 and 80 degrees Fahrenheit, according to NOAA Fisheries. Peirce notes U.K. and Irish waters are within this range, saying, "It's not a question of global warming increasing water temperature, these animals tolerate down to below U.K. winter temperatures."
"While conditions in British waters are theoretically suited to white sharks, no reports to date have given us clear evidence for their presence," Hood told ABC News, "That does suggest that they are not here."
Author of "The U.K. Great White Shark Enigma," Peirce has spearheaded investigations into 100 white shark sightings around the British Isles -- of which 12 remain credible. Peirce said he believes there is "compelling circumstantial evidence" to suggest that rather than a permanent population of white sharks, there may be "the occasional guy walking by and hanging around the beach, and then buzzing off."
The closest recorded sighting of the wide-ranging animal to British waters was in La Rochelle in France in 1977. "For a great white shark that's absolutely nothing," Peirce said, laughing, "it's a day's stroll in the park."
Shark ecologist Max Kimble suggests one reason for their apparent absence from the U.K. and Ireland's "near-perfect habitat suitable" waters may be explained by the "prolonged time" white sharks can spend swimming at depth. Kimble suggests lone males from the Mediterranean population as a likely profile in his research. Kimble told ABC News any data gathered from a tagged white shark in Irish waters would be "monumental," though he'd be most interested to know whether the sharks are from the Mediterranean or Northwest Atlantic population.
"Success on this trip is just a spot tag and a fin clip on one white shark," said Fischer.
"The tag is so we can track it and it can show us its full range over the next five years. The fin clip is just for genetics to understand which other populations it's most related to," Fischer said. The public can follow tagged white sharks on Ocearch's website.
Ocearch's strategy of targeting feeding sites has seen the group tag 200 white sharks across 46 expeditions around the world.
Fischer told ABC News, "We've found it much easier to find these animals when they're in the summer and fall feeding areas than it is when they're in their winter range and spread out over vast areas."
"We see these white sharks around the world in the late summer and fall, moving to areas where there are seal colonies to bulk up for the oncoming winters," he said, adding that when the patterns are applied, "this puts the white sharks somewhere up in Ireland, Scotland, southern England."
With Peirce's "credible" sightings clustered around the southwest of England, and west of the north coast of Scotland, latterly the largest grey seal breeding colony in the Northeast Atlantic can be found in the Monach Isles, he questions how Ocearch will fare on the west coast of Ireland.
“Our original objective was Cornwall and the west coast of Ireland and the Outer Hebrides,” he said, adding, “We tried.” But, he said, Ocearch struggled to persuade “local research partners" with the relevant animal handling permits "to participate in the project".
Ocearch's route will take them past the Great Blasket Island off the coast of Dingle during pupping season, the "grey seal capital of Ireland," according to Blasket Islands Sea Life Tours. When ABC News spoke to Skipper David Flannery, he seemed skeptical about the chances of a white shark sighting, "I've never seen one. There's just plenty of seals and no predators."
Lead scientist on the trip Dr. Nicholas Payne told ABC News one of the main reasons for the trip is learning where Ireland's shark and ray species prefer around the coasts, saying, "Places like the Blaskets are interesting given their seal populations, but I've also got my eyes on Donegal given it's such a bluefin tuna hot spot."
Ocearch won't be the first to search for great whites in Irish waters. O'Sullivan fronted a project that sent an ROV, or remotely operated underwater vehicle, to a depth of 95 m to the site of the Lusitania wreck off the Old Head of Kinsale. He said visibility and resources were the biggest challenges. While Peirce worked on a 2015 project that saw the body of a 30 foot female humpback dragged as bait through the Irish Sea, "the weather came in and we had to dump the carcass early," he said.
Fischer, the founder of Ocearch, told ABC News that "we know our single biggest challenge in Ireland is going to be the weather. Working at these latitudes, we understand that if you go on a three week expedition, you might only be able to work one week."
If the expedition prevails, "the first thing that will happen will be a mass feeding frenzy amongst the tabloids," Peirce said.
In July, a hoax white shark sighting by two Irish fishermen provoked alarming headlines with one local news outlet publishing a story under the headline: "Deadly 'Great White Shark spotted' off Galway coast as swimming warning issued."
The saga "confused" Australian angler Kevin McLoughlin, who told ABC News the tricksters had used an old video he filmed of a white shark approaching his boat in Port Macdonnell, South Australia.
Underwater cameraman Ken O'Sullivan called the coverage "reckless." "They scared tens of thousands of people out of the ocean for what?"
The local news outlet who first reported the hoax, Galway Beo, did not respond to ABC News’ request for comment.
"If we found a white shark, the impact depends wholly on the media reporting around it," O'Sullivan said, scolding the hyperbolic headlines that often coincide with possible sightings, "'Bloodbath on British Beaches' just ridiculous."
"I just think people don't understand because they fall into that typical trap about the trait of the shark," Fischer said. "The main job of the white shark in the region is to guard our fish stocks from seals."
Fischer insists Ocearch isn't really a shark program, saying, "It's an abundance program, trying to ensure that our grandchildren see an ocean full of fish."
"These large apex predators are the balance keepers of the system," he said. "They are the conductor of the ocean orchestra. And if they're not there, it falls terribly out of tune."
Fischer cites reports of the recovering white shark population off North America's Atlantic coast. In the past decade white shark sightings and catch records in the broader Northwest Atlantic have increased following legislation to protect them in 1997 according to Massachusetts Atlantic White Shark Conservancy (AWSC). "We need to make sure we have both sides of the Atlantic thrive," said Fischer.
"Nobody on the planet knows how many we have really got," Peirce said. "Population estimates for white sharks vary wildly."
Citing the sharks' long gestation period, slow growth rate and increased threat from unsustainable overfishing, Peirce said, "They're incredibly vulnerable, if we take out a couple of breeding age animals, it's going to do a lot of harm because it takes a lot of time to produce pups."
White sharks are listed as globally vulnerable by the International Union for Conservation of Nature (IUCN). The population closest to Ireland, the Mediterranean great white shark, is listed as critically endangered.
Peirce maintains "the chances of white sharks reaching our shores are diminishing, not increased. Because we're catching and killing too many."
O'Sullivan said he hopes the trip will bring wider attention to marine conservation in Ireland. Citing an "appalling" 2018 incident in which a Spanish trawler was impounded with more than a tonne of shark fins on board. In its wake the Irish Wildlife Trust (IWT) called for greater legal protection for sharks in Irish waters.
Lead scientist Payne similarly echoes, "Seals and other marine mammals have been officially protected in Ireland for some time, whereas only one shark species -- basking sharks -- is, which helps explain the dire conservation status of many sharks and rays in the region."