A team of marine scientists have discovered a very rare shark nursery, 200 miles west of Ireland while investigating Ireland’s deep ocean territory.
During the SeaRover survey undertaken last July, a rare shark nursery was discovered while exploring Ireland’s deep-water coral reef systems. Very large numbers of egg cases, commonly called mermaids purses, were filmed on the seafloor at depths reaching 750 m. Such large concentrations of egg cases, are rarely recorded and indicate females may gather in this particular area on the seafloor to lay their eggs.
While no shark pups were seen swimming around, there were hundreds of adults—mostly the fairly common blackmouth catshark and some sailfin roughsharks, a normally solitary creature currently listed as near-threatened. It is believed the egg-laying was done by the catsharks, and the roughsharks may have been feasting on the egg buffet.
Within its range, the blackmouth catshark is one of the most abundant sharks over the upper and middle continental slope. It is an active, generalist predator that feeds on both bottom-dwelling and free-swimming organisms. It often cruises just above the sea floor, perhaps taking advantage of the ground effect (a reduction in the drag on a wing when close to the ground) to save energy. It has also been seen resting motionless on the bottom.