Monday, 11 January 2010
Sightings of whales, dolphins and basking sharks off the Northern Ireland coast are becoming more common.
But a new visitor to the Irish Sea has been raising eyebrows in the Republic of Ireland, and it is also quite likely to be in waters nearer home.
The potentially deadly Portuguese Man O' War (physalia physalis), has been seen off the coast of County Louth, with 30 sightings reported to marine researchers last year, stretching from Wexford to the more northerly county.
In 2007, a swarm of Mauve Stinger jellyfish wiped out 100,000 salmon when they swamped a fish farm off Glenarm in County Antrim.
Since then, the Northern Ireland Environment Agency has been working with Queen's University, Belfast, to carry out small scale surveys of jellyfish activity, concentrating on the Mauve Stingers.
The stinger and Man O' War are normally found further offshore and researchers believe it is likely that a combination of warmer seas and prevailing winds, are responsible for both 'stingers' being in the Irish Sea during the autumn of 2009.
"To date, there have been no confirmed sightings of the potentially lethal Portuguese Man O' War jellyfish around Northern Ireland," an NIEA spokesperson said.
"However, during the latter part of 2009 there were several reported sightings from the Isle of Man and County Louth suggesting that it is likely that small numbers have also been in Northern Ireland waters.
"These sightings peaked during September and October with further reports during November and December."
The Mauve Stinger is a very small orange or purple jellyfish, while the Portuguese Man O' War has a very distinctive shape, including a bottle shaped gas bladder and stinging tentacles that can be several metres long.
The Portuguese Man O' War is not a true jellyfish as such, but a siphonophore - a single creature made up of a colony of organisms.
Both have powerful stings that can potentially produce a severe reaction and the NIEA said people should avoid touching them and seek medical advice if stung.
There are at least eight species of jellyfish which are regularly recorded in Northern Ireland waters, including Moon, Lion's Mane, Compass, Root Mouth, By-the-Wind-Sailor, Blue, Portuguese Man O' War and Mauve Stinger.
Half of the species produce powerful stings.