The seas are overfished and undernourished

Another Life Michael Viney There are honeyed days in autumn when the islands laze along our horizon as if the Atlantic were …

Another Life Michael VineyThere are honeyed days in autumn when the islands laze along our horizon as if the Atlantic were the Aegean. Held in the same bowl of golden light, our backs to the mainland mountains, it is easy to feel that Inishbofin, Inishturk and Clare Island, off the coast of Connacht, are more part of our world than anything lying to the east.

Such affinity is strengthened by a new array of aerial rods and radio dishes. Thanks to the enterprise of the inter-island co-operative, we are now an outlying, distributive node of broadband, received from Inishbofin across 16km (10 miles) of sea. We relay the signal to townland neighbours similarly deprived of computer progress by unaccommodating bulges in the hills.

Downloading megabytes of knowledge in seconds, we no longer feel "remote" in any but the best of senses. How this facility will help the islands is thrillingly unpredictable - unless it is to fill them with migrant scholars, as rapt as the monks of Sceilig.

The radio pulse from Inishbofin passes above an obstinate concrete ruin at the tip of the east-end pier - a packing station for barrels of herring before the market collapsed in the early 1900s. About a century before that, thousands of fishermen converged on Inishbofin in summer to catch both herring and basking sharks.

READ MORE

Such history provides ironic footnotes to the global debate on overfishing and threatened commercial extinction, within decades, of one wild species after another. Inexorably, mankind seems impelled towards the same domestication of sea life that it has exerted on land animals.

In June, the US National Oceanographic and Atmospheric Administration proposed laws to extend fish farming up to 320km (200 miles) from the coast.

Ireland, too, has become increasingly conscious of its underwater economic territory. The National Seabed Survey, managed by the Geological Survey of Ireland, has been mapping an area some 10 times that of the land, stretching west and south far beyond the edge of the continental shelf. Celtic Explorer, the Marine Institute's new high-tech research vessel, made its gleaming debut in my study window the other morning, halfway between the strand and Inishbofin, its multi-beam sonar scanning the seabed.

Salmon farming has already shown up the environmental threats from crowded fin-fish cages moored in shallow, sheltered waters. Pollution from food, waste and chemicals, and dramatic increases in parasites and disease have shown the ecological limits to intensive coastal mariculture. Moving further out into the ocean raises costs enormously and makes new technological demands, but may seem inevitable.

A recent article in Nature reviewed some possibilities now under development in the US. Giant versions of coastal fish pens, jailing some 100,000 cubic metres of water, are being designed to drift freely in the ocean. In one proposal, fingerling fish will be confined in the pens in Florida, then drift for many months at depths well below the surface, until the Gulf Stream and North Atlantic currents deliver them in Europe - perhaps to Ireland - at marketable size. The scanty plankton of mid-ocean would be augmented by automatic feeding at satellite command.

Another almost equally mind-boggling proposal exploits the natural behaviour of tuna, one of the most valuable types of fish in the sea. They are attracted, it seems, to any novelty in their surroundings: a floating log or a buoy or some disturbance at the surface can gather them together. "Fishing boats directing a fire hose behind them create just such a disturbance," wrote Columbia University's John Marra in Nature, "and can thereby attract a following of tuna." The fish "will never be domesticated, as are sheep or cattle," he admitted, "but the analogy of herding on the 'high plains' of the sea still holds".

His vision of taming the oceans, however desperately framed, has brought a heartfelt retort from three university biologists in Nova Scotia. They focus especially on the wholesale use of mixed small fish as feed for penned carnivores, resulting in a net loss of nourishment. Farming tuna, for example, "is not like herding cattle: it is the ecological equivalent of trapping wild shrews and foxes to feed caged wolves".

They argue in favour of restoring the wild fish populations by creating large marine reserves and cutting back on fishing capacity. "Proper management of wild marine life," they insist, "could yield remarkable results." Ireland's continental shelf and inshore waters could yet, as I fervently hope, be the arena that proves them right.