WE WERE SHARING end-of-holiday thoughts above the Bay of Biscay, flying home across a sunlit ocean. At Thallabawn, our own small stretch of Mayo shore, the Atlantic never had quite that golden shimmer. We'd lived beside it for most of 30 years. A need for the ocean seemed, indeed, bred into both of us, along with a sizeable bump of curiosity.
The many sea creatures washed up by the tide (whales, turtles, jellyfish, strange fishes) had led us into learning, yet what we really knew about the sea still seemed little more than knee-deep.
Here was Ireland spending millions on marine research, and mapping and surveying a great wedge of sea floor 10 times as big as the State. Yet most people found the sea still deeply unknowable, just providing more worrying news about the future along with everything else. There was still no Irish book for the general reader, opening wider windows to the ocean's life and promise. Five years on, we have tried to provide it.
Ireland's Ocean: A Natural History (Collins Press, €29.95) takes a broad view: waves and jellyfish on the front cover; wind turbines on the back. It ranges over the currents, the great rivers and streams of the ocean that influence our weather, and the diversity and beauty of the life off our shores. What with overfishing, pollution and carbon acidification of the sea, it was not the simple, bright journey into wonder that it might once have been. But enough promising things were happening in Ireland's marine science to let the beauty, the fascination, shine through.
With a broadband aerial on the gable, Ethna researched, built and distilled the book's database. It reached out to the latest research on both sides of the Atlantic, from the Marine Institute and the Martin Ryan Institute on Galway Bay to Woods Hole on the shores of Maine, from Southampton on the English Channel and Brest and Roscoff in Brittany, to the deep-sea explorers of Norway and Germany.
Like everyone who lives beside the sea, we have wondered what the bottom would look like with all the water gone. The appearance offshore of the Celtic Explorer, the Marine Institute's new high-tech research vessel, brought the National Seabed Survey to our doorstep. The ship was one of those chartered by the Geological Survey of Ireland, using multi-beam sonar on the vast area to which Ireland laid claim in the international share-out under the Convention of the Law of the Sea. Thanks to the meandering sculpture of the continental shelf, our mineral and oil/gas rights now extend way out past the great Rockall Trough to the Hatton Basin - in all, some 200,000sq km of sea floor.
The survey went further than merely mapping the surface and geology of plains, canyons, cliffs and seamounts, much of it totally unplumbed territory. While the ships ploughed the waves, ancillary projects managed by the Marine Institute sampled the rich life of the seabed ooze, the species of plankton, the chemistry of currents and their flow - all vital knowledge of the ecosystem, especially as the ocean warms. And the deep-sea discovery in the middle of it all was the astonishing extent of species-rich cold-water coral reefs in the Porcupine Basin, off the southwest of Ireland, and on the steep slopes of the Rockall Trough.
Damage to the reefs by deep-sea trawling, such as the lethal "ghost-fishing" of lost or abandoned nets, has been just another sad abuse in the mismanagement of modern fisheries, not least in the EU's attempts at regulation. Learning about fish biology and behaviour led us on to the fortunes of fish populations and the constant battles between marine science and politics, such as the one scheduled again for Brussels next week. Measuring the state of fish stocks involves variables to make one's head spin.
Amid today's economic dramas, the Government has stuck, so far, to its investment in applied science and RD. Among the many prospects are wave energy, offshore aquaculture and "biodiscovery". From seaweeds and sponges at the shore to organisms of the deep-sea corals will come biopharmaceuticals, biomaterials, biofilms, and more we haven't thought of.
Fishery science has turned away from its historic compulsion to study, one by one, individual stocks of human food fish. Its new "ecosystem approach" takes into account the interwoven networks of species and habitats, and this guided the themes of Ireland's Ocean. The further we delved into the undersea world, the more we were struck by its intricate patterns of predation, from microscopic plankton right up to giant blue whales, a profusion of eat-and-be-eaten. While enjoying the pleasure of discovery, however, we were enchanted by the beauty in the least of creatures: crystal jewels of plankton, flowering worms, dazzling cuttlefish, amazing sea slugs, gorgeous anemones, in colours that match any species on the land.
FROM SHIP TO SHORE
Commissioning of the Celtic Explorer at Galway five years ago brought the Marine Institute to the forefront of Atlantic research. The 65m research vessel, highly sophisticated and six times the overall size of the older Celtic Voyager, is "acoustically silent" for surveys of fish stocks. Last summer, it was pursuing young salmon above the edge of the continental shelf - part of an international investigation into their decline.
With cabins and laboratories for up to 18 scientists, the Explorer is a platform both for the Marine Institute and researchers from Irish and foreign universities and institutes of technology. Climate change has opened up new and urgent questions - on the interplay of ocean and atmosphere, on shifts in major currents, water chemistry and plankton populations, on the spread of new species in the waters around Ireland.
The Explorer has helped sow the global network of sunken buoys that now pop up to radio data to satellites. Galway and Limerick universities are working on systems for new underwater robots. And there are plans to put the ocean online - cabling whole swathes of the sea floor, as far out as the Porcupine Seabight, with sensors and cameras feeding back to the land.
CORAL JEWELS
Exquisite feather stars, or sea lilies, are typical of ocean animals that take on forms we know better in land plants. They are among the myriad species - 1,317 at a recent count - that live on, in, or around the deep-sea coral reefs of the Porcupine Seabight and Rockall Trough. The huge number of coral-topped mounds, first revealed by multi-beam sonar, then explored by the cameras of remotely operated vehicles (ROVs), has been one of the most exciting discoveries of marine science.
The reefs form a seabed archipelago stretching in a great arc from Spain to Norway, but nowhere in the Atlantic are they bigger, more abundant and diverse in species than off Ireland. They serve as "cities" of marine life, including many fish, and damage from deep-sea trawling has prompted protection of four key clusters of reefs as "Special Areas of Conservation" covering a total of 2,500sq km.
The extreme conditions of deep, cold water have produced reef organisms with exotic and novel biochemistry. This adds to the promise of new drugs and other compounds - and also to the threat of uncontrolled "bioprospecting".
JELLYFISH EXPLOSION
Individually beautiful, but potentially lethal en masse, the "purple stinger" jellyfish, Pelagia noctiluca, brought disaster to a Co Antrim salmon farm in late 2007. Normally an oceanic, warm-water species, it was carried into the Irish Sea in billions and concentrated by tide and wind into a dense mass in Glenarm Bay that, fragmenting into the cages, killed more than 100,000 fish.
In some heavily trawled waters, such as those off southwest Africa, the biomass of jellyfish is now greater than the total weight of remaining commercial fish. In the northeast Atlantic, all projections warn of an increase in jellyfish, even to population explosions, especially in years when warmer water is drawn northwards. Among them are minute and toxic jellies quite different from the larger species stranded on Irish beaches.
The few predators on jellyfish include the two-metre leatherback turtle, which migrates to the Irish Sea to feed on local concentrations of the meaty barrel jellyfish, Rhizostoma, and also the big, vertically swimming sunfish, Mola mola, which is becoming more plentiful around our coasts. Irish and Welsh marine scientists work together on this suddenly important network of ocean ecology.
WAVERIDERS
The challenge of Aill na Searrach, a great 10m wave shelving beneath the Cliffs of Moher, has become famous across the surfing world. It speaks for the massive energy waves borrow from the wind.
Their heights are measured by the Marine Institute's yellow weather buoys - the newest, the M6, is moored above the Rockall Trough in 3,000m of water. The European Wave Atlas shows the west of Ireland receiving the most powerful waves of all, and another atlas, commissioned by the Marine Institute and Sustainable Energy Ireland, plots the contours of accessible wavepower around the Irish coast at different times of year. Its theoretical contribution to the electricity grid worked out at 75 per cent of the electricity we used in 2006.
The perfecting of wave machines sufficiently tough and durable to produce energy reliably, and at sufficient scale, year after year, has proved a long and costly challenge. Ireland's first generators were tested as models in a wave tank at NUI Cork and subsequently at quarter-size in the waves of Galway Bay.
SECURING THE SEABED
The dramatic planting of a Russian flag on the seabed at the North Pole last year heralded a new instalment in the long saga of sharing out ocean rights and wealth between nations. But Ireland has already made its claim to an Exclusive Economic Zone granting it special rights over seabed exploration and use of marine resources in a vast triangle of the Atlantic.
The UN Conference on the Law of the Sea, set up in 1973, took nine years to reach the convention known as UNCLOS, now ratified by 155 countries. It allows maritime states to assert rights far beyond the standard Exclusive Economic Zone of 200 nautical miles from the coast, but the claim has to be based on geological criteria for a "natural prolongation" across the continental shelf up to 350 miles out.
The nearest edges of the shelf can arrive surprisingly quickly - a mere 30km off the north coast of Mayo and 60km off Kerry. But the outlying troughs and basins have let Ireland claim a share of the Atlantic some 10 times the size of the State. The National Seabed Survey has been carried out within its borders.