Teams of researchers are mapping Ireland's massive continental shelf. Marine Correspondent Lorna Siggins reports
A €100,000 fisherman's trawl, complete with nets and electronic sensors, is no mean piece of equipment. Yet forfeiting such expensive gear can be a regular occupational hazard on exploratory fishing trips. Now, application of data acquired during the State's national sea-bed survey may help prevent such losses.
Early in the new year, trials are due to begin using a video chart plotting system, based on information gathered during the €32 million, seven-year, sea-bed survey. The system will display high definition three-dimensional images of more than 420,000 square kilometres of sea-bed, ranging from 200 metres down to 4,500 metres depth.
Colour-coded relief maps on paper have already been made available to fishermen by the Geological Survey of Ireland (GSI), and the software for same has now been produced in a public-private partnership deal involving Bord Iascaigh Mhara (BIM) and Barry Electronics of Killybegs, Co Donegal.
"A virtual-reality colour display of the details and contours of the sea-bed," is how Barry Sharkey, managing director of the Killybegs firm, describes it. The imagery will not only assist fishing skippers to open up new grounds without having to fish "blind" with the risk of losing valuable gear, but will also identify environmentally sensitive areas. This includes deep- water coral beds and wrecks of archaeological value.
Multibeam "backscatter" maps have also been developed to provide a measure of sea-bed hardness, and will enable fishermen to identify the ground type, and associated target species - such as prawns in sandy ground.
Mind you, Irish skippers will only have three years' march on their European rivals. After that date, the data will be made available for distribution throughout Europe, Sharkey says. "So, no, we are not giving it to the Spaniards this Christmas, but . . !"
The fisheries bathymetry project is one of a series which mark a new phase in the GSI's sea-bed survey, as the GSI's director, Dr Peadar McArdle outlined at a seminar hosted by the GSI in Dublin late last month. Geologists and marine scientists are now "adding value" to a large volume of new material gathered over the last thee years.
Data acquisition hasn't quite ceased, he emphasised, given that the total area is over 10 times the island's landmass. However,detailed studies of just under 450,000 square kilometres of sea-bed have been completed.
Deep-water surveying was concluded by Irish company, Gotech, in June of last year. Vessels contracted to that former company were among a fleet of 10 ships and one aeroplane involved in the survey since it began in 2000. The Marine Institute's Celtic Explorer will continue working in Zone Two (50 to 200 metres in depth) until 2005. The Commissioners of Irish Lights vessel Granuaile, the British Antarctic Survey's vessel, J Clark Ross, and the German research vessel, Polarstern, have also been involved for specific aspects.
Progress tends to be slower in shallower water, Enda Gallagher of the GSI says, but the Celtic Explorer completed five scheduled legs of Zone Two in Donegal Bay this year, representing more than 13.4 per cent of that total area. The ship identified over 100 wrecks, some of which had not previously been charted in Donegal Bay.
Last year's successful aerial survey of Clew Bay in Zone One (zero to 50 metres contour) was extended this year, with further work on Clew Bay, Newport Bay and Killala Bay, Co Mayo, in September. Trinity College, Dublin, is working on a geological interpretation of the survey data for the Continental Shelf, extending from Galway and Donegal bays, while UCD is investigating possible occurrence of methane hydrates and related shallow gas in Irish territorial waters.
University College, Cork, is involved in a proposal to drill carbonate mounds in the Porcupine Seabight, and NUI, Galway is focusing on cable and pipeline routes. Some 29 academics are currently using the data, but many more are anticipated - and the survey has employed the expertise of about 825 people in all over the last three years, the seminar heard.
Further information on the National Sea-bed Survey is available on website www.gsiseabed.ie