Seeing is believing as coastline alive with top predators

The coast of Cork is alive with whales and top marine predators of all kinds.

Seeing is believing as coastline alive with top predators

The coast of Cork is alive with whales and top marine predators of all kinds.

“You watch David Attenborough and we go to Alaska and South Africa with him on screen to see whales and sharks and dolphins, but this is all happening in Ireland, this is all happening on the west of Ireland,” said Simon Berrow of the Irish Whale and Dolphin Group (IWDG).

On-board the Celtic Voyager — a Marine Institute-owned research vehicle — IWDG is currently undertaking a first-of-its-kind expedition off the Irish coast, tracking marine wildlife, with GMIT and NUI Galway.

“We’ve seen six species now, of whales, dolphins and sharks.

We met eight to 10 fin whales lunge-feeding off the Fastnet Rock the other day. The fish were close to the surface, so the whales were throwing themselves on their sides and then getting the fish. You could see the blows of whales everywhere.

“These guys are 70-80 feet long and weigh up to 60 tonnes,” said Mr Berrow.

“We’ve also seen plenty of blue sharks cruising at the surface and bluefin tuna, which are as big as dolphins,” he added.

NUIG/GMIT and the Irish Whale and Dolphin Group are currently tracking marine wildlife along the coast between Cork and Galway. Picture: Simon Berrow/IWDG
NUIG/GMIT and the Irish Whale and Dolphin Group are currently tracking marine wildlife along the coast between Cork and Galway. Picture: Simon Berrow/IWDG

The current expedition is tracking several things including where marine predators gather off the Irish coast, what their food supply is, and using a homophone towed at the back of the Celtic Voyager, the communications of the whales and dolphins are being recorded.

Off the west coast, there is a sudden sea cliff where the water depth goes from 200 metres to about 1,000 metres in depth. When the gulf stream reaches this dramatic contour it pushes nutrient-rich water to the surface and the area becomes a popular feeding ground for marine wildlife.

However, this expedition is surveying the 100-metre contour line, so where the water depth is at 100 metres. The is also a very nutrient-rich area in our waters, and a place where humpback whales are often seen around the Blasket Islands.

Although the depth is 100 metres, the expedition has had to only go as little as one mile off-shore and as far as 40 miles off-shore.

“So south of Cork we went about 30 miles out, 40 miles was definitely the furthest off-shore we went. In west Kerry we were five miles off-shore, and at Bull Rock off Cork, we only needed to go one or two miles out,” Mr Berrow said.

A blue shark is one of the predators found in our waters. Picture: Sibéal Regan/GMIT
A blue shark is one of the predators found in our waters. Picture: Sibéal Regan/GMIT

“This is the first targeted survey of the 100-metre contour, combining oceanographers and biologists,” he added.

Sean O’Callaghan is on-board the expedition and is the science officer with IWDG.

He said there is a lot of “feeding activity off Cork between the whales and dolphins and tuna and birds”.

Using the homophone, Mr O’Callaghan said you can hear “the dolphins whistling away”.

However, top of the marine food chain is the orca or killer whale, as well as the fin whale, and while they haven’t encountered any orcas on this trip, they have just recently been seen off our western coast.

“The top predator would be the killer whale who have been known to take porpoises. Two orcas were seen off Kilkee in Clare last week,” said Mr O’Callaghan.

Mr Berrow believes that this level of activity could sustain marine wildlife tourism off our western coast.

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