The researchers use underwater microphones, or hydrophones, to pick up the noise from blasts. The detection range for each hydrophone is around 30 kilometres and the team has developed software to calculate the direction of a blast from the slight time difference between the noise reaching each of three hydrophones.
New Scientist vol. 177 issue 2377 – January 11 2003, page 6
The above quote is taken from an article describing the satisfaction of a team of researchers from Hong Kong who, using sophisticated technologies, have managed at last to find an effective way of identifying the numerous fleets that fish illegally along the coral reefs of south-east Asia and down the east coast of Africa, using bombs to increase their catch. To date, all attempts to survey these vast areas have been in vain, and blast fishing has consequently proliferated, causing dreadful damage to the marine ecosystem and coral reefs that are rare treasure troves of biodiversity. In despair at the diffusion of these criminal practices, coastguards have virtually thrown in the towel. The news item I cite above provides, thank goodness, a breath of fresh, but it’s hard to believe that the unscrupulous fishermen in question will suddenly stop devastating the sea just like that. More in general, the problem of unsustainable fishing now affects almost all the world’s seas, from Oceania to the coasts of Newfoundland, from Antarctica to the Mediterranean. The European Commission is working hard to find a remedy and fix a limit on the over-exploitation of its seas. All the world’s governments and the ministers of nation tied to fishing have already been asked to take measures. In the meantime, whalers, hyper-technological fleets backed by aeroplanes, the Japanese ships which station off the Straits of Gibraltar, ready to massacre red tuna fish (which come to produce in the Mediterranean, where they are subject to catch limitations) and date mussel scavengers are all carrying on their dirty habits regardless. But think about the oil tankers that almost seem to come aground at the points richest in biodiversity and fishing resources on purpose, and by comparison the over-exploitation of the world’s fishing stocks may seem like a joke. But it isn’t. There’s hardly any trace left of the legendary Newfoundland cod and the ban on fishing in those areas may have arrived too late—the shoals just can’t restock any more. Red tuna apart, in the single nations of the Mediterranean, there are limitations on fishing only to control prices or defend some species in their mating seasons. But the situations of swordfish, other types of tuna, sardines, anchovies and some crustaceans are by no means healthy either. Add to that wildcat trawler and coastal fishing, plus the fact that most edible fish gets thrown back into the sea dead because there is no demand for certain less ‘noble’ varieties on the market, and it becomes clear that the situation is about to become irreversible. Before coming to the sticky end of Newfoundland and paying the price of irresponsible slowness to act, let‘s follow the example of Tasmania. Scallops down under were slowly disappearing. To address the situation, the authorities lost no time in blocking fishing for three years and, as a result, they are now in a position to reopen it and create hundreds of new jobs. Tasmania teaches that it is better to call a halt for a while rather than stop for good. In the meantime, why not improve methods of aquaculture, seeking to realize develop sustainable nurseries with slightly lower yields and without an excessive use of antibiotics? Last but not least, we as consumers should not lose sight of our responsibilities. So be careful about what you order at restaurants and treat yourself to ‘forgotten’ fish, the stuff they generally chuck back into the sea because no one buys it any more
First published in La Stampa on19/01/2003
Adapted by John Irving