11
surface temperatures and the breakdown or rise in depth of the thermocline when the sardinellas undertake a spawning andor feeding migration. Usually, the bulk of the fish is
first seen in the Western Region of Ghana and moves eastwards, apparently following a migration pattern proposed by Ansa-Emmim 1976. The eastwards movement continues into
the Republic of Togo and to a lesser extent the Republic of Benin.
Sardinella aurita
is the main candidate in this migration which was known by the early fishers and which widened
their fishers movement. There have been occasional departures from this general pattern of fishing Koranteng, 1989, as the Greater Accra and Volta Regions often record smaller than
usual proportions of landings of
Sardinella aurita
. Pezennec and Bad 1992 and Pezennec this series have noted some of the changes in the upwelling, especially the minor upwelling,
and the resultant effects on the distribution, abundance and fishery of sardinellas in the Ivoiro-Ghanaian ecosystem.
2.5 Catch Effort and Performance of Fishing Fleets
Like al1 pelagic fishery resources, the landings of sardinellas in Ghana have usually fluctuated from year to year. These fluctuations have sometimes given cause to fishers and
fisheries managers to worry. There was a bumper harvest of sardinellas and other small pelagics in 1972. Landings in the three ensuing years were so low that the fishery was
thought to have collapsed. Since the early 1980s there has been an increasing trend in the landings of sardinellas, especially of
Sardinella aurita
. These increases in landings have, however, not been commensurate with assessments of the biomass of the resource. For
example in acoustic surveys conducted with RV Dr. Fridjoft Nansen Stromme, 1983 and RV Cornide de Saavedra Oliver
et al
., 1986, the combined biomass of the two sardinellas and anchovy in Ghanaian waters was estimated at 40,000 and 74,000 tonnes respectively. In
the years during which the surveys were conducted, the total landings of sardinellas alone were nearly 30,000 and 70,000 for 1981 and 1986 respectively.
2.6 Post-harvest processing
Atikpo
et al
. 1992 explained that, the most significant pelagic species of fish landed by Ghanaian canoe fisheries are the sardinellas
Sardinella aurita
and
Sardinella maderensis
and the anchovy
Engraulis encrasicolus
. According to Antwi 2006, various traditional methods are employed to preserve and process fish for consumption and storage. These
include smoking, drying, salting, frying, fermenting and various combinations of these.
Among the various traditional processing methods employed in Ghana to preserve fish, smoking and sun-drying are the most widely used techniques for anchovies Atikpo
et al
., 1992. Smoking is the most widely practised method; practically all species of fish available
in the country can be smoked and it has been estimated that 70-80 percent of the domestic marine and freshwater catch is consumed in smoked form. Fish smoking in Ghana is
traditionally carried out by women in coastal towns and villages, along river banks and on the shores of Lake Volta. Efforts are being made to improve the traditional methods of smoking,
salting and drying. The main species smoked traditionally are the anchovy, sardinella, chub and horse mackerels. In 2002, the quantity of smoked fish exported was 5,312 MT with a
value of US4,380,199; that for 2003 was 6,031 MT with a value of US3,291,750 GEPC, 2005.
2.7 Trade and Markets
