| The fishing by the sluice, employed in the brackish fish ponds of Arcachon Bay, catchs only the migrating eels. The exploitation by this process is not more than the 18 percent of the biomass. The structure of the migrating eels caught in winter 1977-78 was estimated using the double sampling method with length as strata. The sexratio was about 1.1. The males migrate to the sea from 3 to 7 years after of the brackish water life (maximum 5 years old) and the females leave the fish ponds, generally from 5 to 9 years after (maximum 7 years old). The estimated mean lengths, 37.5 cm for the males and 49.8 cm for the females, were much smaller than-those which were estimated in the Italian "Vallis" |
