Divers to swim with sharks to solve bay mystery

Diving enthusiasts are swapping South Yorkshire for Scotland as they prepare to go swimming with sharks for a conservation project.

Members of Dearne Valley Divers are heading north to take a dip with a shiver of tope sharks and help marine biologists understand the fish.

Each year dozens of tope sharks gather off the Inner Hebrides for a month - but experts say they cannot understand why.

The sharks are critically endangered and the divers have teamed up with university academics to understand why they gather at the location and how they can be protected.

Rob Mason, one of the instructors at Dearne Valley Divers, was on a family holiday in Tiree, the most westerly island in the Inner Hebrides, when he first became aware of the sharks.

"We were walking around some of the absolutely gorgeous sands and landscapes up there, ivory-coloured sands and azure-coloured seas, when we stumbled across a quite isolated bay," he says.

"One of the locals asked me if I was there to see the sharks, which raised my eyebrows, and he then started telling me about all of these sharks which aggregate together in this bay late evening in the middle of summer.

"I was intrigued so I came back and was mesmerised by literally hundreds of sharks in this bay. You could see all the black slits in the water, they ranged from one to two metres in size.

"It struck me as being really unusual as I've conducted more than 700 dives across the world but I've never come across anything like that. I came away with an idea to investigate further and when I told the club, it seemed to spark so much enthusiasm and interest."

The club began in the 1980s and now has about 60 members, ranging from children to over-65s, who train at Dearneside Leisure Centre.

Rob says: "We often dive in UK seas because we have some of the best wrecks in the world, there are 20,000 wrecks scattered around our shores and a really rich ecosystem.

"We go from as far up north as Orkney and Shetland Isles all the way down to the Isles of Scilly and the ecosystems between those two points are so wide and varied."

The club decided to do a dive at Tiree, and organised the outing with the help of the British Sub-Aqua Club and the Shark Trust conservation charity.

Twenty divers will spend the next few weeks undertaking detailed surveys for Edinburgh Napier University, which leads groundbreaking research into sharks in Scottish waters.

Rob says: "We really want to get some useful data to pass on to the university so hopefully they can establish what is special about that bay and why it is attracting sharks in such high numbers.

"They are classic looking sharks, about one to two metres in length, but they are not dangerous, there are no documented or known attacks on people in the water from these sharks.

"If we can understand why they gather at Tiree that may help boost conservation work around the protection of that species.

"There are excursions where people can book to go and fish for toper sharks but we want to make people aware they are a critically endangered species so people fish more responsibly.

"We have a 'look, don't touch' ethos so we leave the ocean as we found it. It is about sharing the space and one of the reasons we reached out to specialists was to make sure we were diving responsibly.

"It is a very special environment up on Tiree, we don't want to disturb the sharks, we don't want to chase them or drive them out of their base so we are making sure we contribute to valuable research while at the same time not interfering with nature."

Tope sharks appear as critically endangered on the International Union for Conservation of Nature's Red List of Threatened Species.

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