Factors and constraints of the commercial fishing activity in the Central Amazon: a case study of a floodplain lake (The "Lago do Rei", Amazon, Brazil)
Following the observation that the commercial landings of fish on Manaus market are predominantly produced by the floodplain fisheries, a detailed case study was conducted in a floodplain lake near Manaus. The general characteristics of the fisheries exhibit a high level of complexity which can be reduced by considering two types of fisheries: a migration fishery and a lacustrine one. A study of the seasonal variability shows complex relationships between capture, effort and cpue, and the hydrological regime. The interannual evolution of these fisheries from 1976 to 1988 is analyzed. The total annual landings are maximum in the years 1979 and 1980, then decrease until the 1983/84 fishing season and seem to stabilize at a relatively low level in the last years. The main factor for these variations seems to be natural fluctuations in the fish populations