During scuba diving research scientists have discovered 28 new species of sponge in the waters off Rathlin Island, including three types previously unrecorded in British and Irish waters.
Researchers from the Ulster Museum identified the new species among some 128 different types of sponge within Rathlin's coastal zone during a six-week diving survey of the island's fauna. Nine of the types are new to Northern Ireland.
Sponges feed by filtering particles from the water, and play a key role in the marine environment. They can be found in cold waters and the tropics, with up to 15,000 species worldwide - some 400 of which are found in these waters.
Rathlin's position some six miles off the north coast and in the middle of the North Channel at the northern end of the Irish Sea exposes it to very strong tidal streams of up to eight knots in speed. Its sea cliffs extend to over 200 metres below sea level, and its biodiversity is recognised with a Special Area of Conservation designation under the EU Habitats Directive.
A researcher on the Ulster Museum project, Claire Good- win, said that some 849 specimens were collected during the survey, and a further 19 species are being investigated. "We suspect that some of these may also be new to science," she said.
Bernard Picton, curator of marine invertebrates in the Ulster Museum's department of zoology and director of the project, said the information suggested that Rathlin is now not only one of the most important areas for sponges in British and Irish waters. "These findings make it one of the most important areas in Europe," he said, adding that the project's results "surpassed our expectations".
The researchers took more than 3,000 photographs, capturing sponges in their living environment - in many cases for the first time. Samples collected during dredging and other marine activities tend to lose their colouring.
The Rathlin sponge biodiversity project was part-financed by European Union structural funds, and the survey was recorded for BBC Northern Ireland's Waterworld television series which will be broadcast later this year.