A team of marine scientists has found a shark nursery, 200 miles west of Ireland.

The very rare discovery was found by a remotely-operated vehicle and detailed seabed maps.

The announcement was made at a seabed mapping seminar in Kinsale, where video highlights were shown.

The programme, known as INFOMAR, is a Government initiative funded by Department of the Environment.

Chief scientist on the SeaRover survey, David O'Sullivan, said: "We are delighted to report the discovery of a rare shark nursery on a scale not previously documented in Irish waters.

"This discovery shows the significance of documenting sensitive marine habitats, and will give us a better understanding of the biology of these beautiful animals and their ecosystem function in Ireland's biologically sensitive area."

During a SeaRover survey last July, the shark nursery was discovered while exploring deep-water coral reef systems.

Degraded coral reef

Very large numbers of egg cases, commonly called mermaids purses, were filmed on the seafloor at depths reaching 750m.

Such large concentrations are rarely recorded, and indicate females may gather in this particular area on the seafloor to lay their eggs.

A large school of Blackmouth catshark were at the site - it is likely the eggs are of this species.

A second, more unusual species, the Sailfin roughshark, was also seen.

"Both species are of scientific interest as Ireland has an obligation to monitor deepwater sharks under the Marine Strategy Framework Directive", said Maurice Clarke from the Fisheries Ecosystem Advisory Services at the Marine Institute.

No pups were seen at the site and it is believed the adult sharks might be using degraded coral reef and exposed carbonate rock to lay their eggs.

It is believed a healthy coral reef in the vicinity may act as a refuge for the shark pups once they hatch.

"It is thought further study of the site will answer some important scientific questions on the biology and ecology of deep water sharks in Irish waters," Mr O'Sullivan added.