Scientists from the Marine Institute made a rare find in an expedition 200 miles of the coast of Galway, a shark nursery.
The discovery was made by the Marine Institute’s remote operated vehicle, the ROV Holland I, during the recent ‘SeaRover’ survey exploring Ireland’s deep ocean coral.
Video taken at the site 750m below the surface showed a large number of egg case, commonly called mermaid purses.
There was an unusually large concentration of eggs found, indicating that female sharks might gather at this particular spot to lay their eggs.
There was also a large school of Blackmouth Catshark, common in the northeast Atlantic, present at the site as well as the more solitary Sailfin roughshark.
The Sailfin roughshark is listed as ‘Near Threatened’ by the International Union for Conservation of Nature meaning it may be considered threatened with extinction in the near future.
They can grow up to 1.2m long and are usually found moving slowly on deep water currents, feeding on small invertebrates.
It’s likely that the eggs were of the Blackmouth Catshark, and it’s possible that the Sailfin sharks were there to feed on them, though this was not observed.
The footage of the shark nursery was presented at the NFOMAR Seabed Mapping Seminar in Kinsale this week.
David O’Sullivan Chief Scientist on the SeaRover survey said: “No pups were obvious at the site and it is believed that the adult sharks might be utilising degraded coral reef and exposed carbonate rock on which to lay their eggs.”
According to Mr O’Sullivan, having a nearby coral reef would provide great shelter for juvenile sharks once they hatch.
“It is anticipated that further study of the site will answer some important scientific questions on the biology and ecology of deep water sharks in Irish waters,” explained David O’Sullivan.
The shark nursery was found withing one of Ireland’s six Special Areas of Conservation that host a wide range of sea fans, sponges, worms, starfish, crustaceans and fish species.
This latest discovery further highlights how important it is to protect the ocean habitats that host such a wide range of sea life.
“Our key objective is to assess, protect and monitor Ireland’s rich offshore marine biodiversity so we can begin to manage our marine resources effectively,” said Dr. Yvonne Leahy of the National Parks and Wildlife Service.
“Without knowledge of what lives in our seas we are at risk of never fully understanding and appreciating Ireland’s marine environment.”
The ‘SeaRover’ survey that found this shark nursery was the second of three ocean surveys backed by the Irish government and the EU.
