Anchovy (Engraulis encrasicolus, L.) is one the most important commercial species of the Adriatic Sea. With a surface area of 138,000 km2, about one twentieth of the Mediterranean Sea, the Adriatic Sea produced about 13,000 tonnes of anchovy in 1991, equal to 19% of the Mediterranean anchovy catches. The value of Adriatic anchovy catches has been estimated at about 15.6 MECU in 1991. Adriatic anchovy catches were very high in the late seventies (53,000 tonnes, average 1978-1980), then they decreased in the following years, until they collapsed in 1987. During this year, with a fishing effort similar to previous years, catches were only 3,700 tonnes. In successive years, stock recovered partially and anchovy catches increased to 10,000-15,000 tonnes. Anchovy is caught by Italian fishermen using two kind of fishing gears: mid-water pair trawls (Italian name is volante) and purse seines (Italian name is lampara). The same fishing gears also catch sardines (Sardina pilchardus, Walb.). The volante is mainly used in the northern and central Adriatic. At present about 70 couples of fishing vessels use this gear, their average engine power is 400 HP, average size of the vessels is 50 GRT. The lampara vessels operating in the Adriatic Sea number about 40 and they are concentrated, mainly, in the southern part of the Adriatic Sea. The lampara vessels, generally, have a bigger size than volante vessels (average of GRT is 85), but they have lower engine power (average of HP is 300). Since 1975, IRPEM has carried out a research programme on stock assessment of Engraulis encrasicolus (L.) and Sardina pilchardus (Walb.) in the Adriatic Sea, using population dynamic models. IRPEM collects catches by species (anchovy and sardine), effort data, fishing fleet characteristics and length frequency data. Stock assessments and biomass estimations of anchovy have been carried out in the last twenty years using direct methods as echosurveys and ichthyoplankton surveys as well as indirect (catch and effort and VPA) methods. Anchovies biomass is estimated around 50,000 tonnes in the years 1990-1992. In recent years anchovy catches are about the 30% of estimated biomass. The exploitable stock size each year seems determined in the main by the size of the recruitment in the two immediately preceding years rather than by the prevailing levels of fishing effort. |