First ‘sea farm’ brings increased fish catches

THESSALONIKI – Devices that are submerged in the sea to «call fish to dinner» are to be tested by experts from the Kavala Institute of Fisheries Research (ETHIAGE) in the first and so far only artificial reef in the country. It was built as a refuge for fish in 1999 in the sea near Fanari, Rhodope, in northern Greece. It is the first time such advanced technology has been used in Greek waters, although the method is also known in other countries. Japan, for example, which has the greatest number of sea farms in the world, has been using similar methods to attract fish for a number of years. The experts at ETHIAGE, which is based at Nea Peramo, Kavala, are to experiment on their own premises initially on the responses of the gilthead bream (dorado). If the devices prove effective during trials, they will be put to use on the artificial reef. Biologists explain that the sound waves produced by the devices are aimed at the fishes’ reflexes. As soon as the device is put into operation, the fish gather at the site, where they learn to associate the sound with food. The results obtained from the Fanari reef have greatly benefited local fishermen. The scientists expect similar results from the other three reefs to be installed by the Agriculture Ministry at the end of next year in the sea near Ierissos on the Halkidiki peninsula, at Parga, and on the island of Kalymnos. The purpose of these reefs (each of which costs a million euros to construct), is to act as the central point for protected fishing zones where populations of local species will be able to multiply so as to enrich fishing reserves. There is a great need for them due to the destructive effects of intensive fishing in Greek waters and from the reduction in the number of species that once thrived here. Italy has 90 of these reefs, Spain over 100. The US has over 1,000 – even old aircraft are submerged for this purpose – which are rented to the public. The artificial reef designed, built and studied at Fanari by ETHIAGE and the Institute for Marine Biology of Crete has resulted in an explosion in the population of fish in the area. According to ETHIAGE’s director, Argyris Kallianiotis, increases of 400-800 percent were observed among some species. Populations of perch, calamari, cuttlefish and bogue have doubled and even tripled. The complicated device is 8 meters tall. It has been submerged to a depth of 23 meters, 3 nautical miles from the coast of Rhodope in an area where fishing stocks have been depleted. The submerged blocks were placed in a pyramidal shape, the peak of which is 15 meters from the surface so as not to cause problems for shipping. The entire protected area is 1×3 miles, within which fishing is banned. Most fishermen in the area are happy to obey this prohibition since realizing the benefits it has brought to their catches. According to Kallianiotis, there are now not only a large number of species living in the reef but increased fish populations throughout the region. This expansion is the most encouraging indication that will lead to the creation of other such reefs in Greek waters.