Abstract:
In this study an analysis of the commercial fishery of the Loreto Region, with emphasis on the fishery fleet of Iquitos, Amazon Basin, Peru, is presented. There is evidence of a progressive replacement of large species by smaller, more productive and lower value species in the landing of the commercial fishery in the Loreto region. Strong fishing pressure has produced a decrease of large valuable species such as Brachyplaiystoma flavicans in the commercial landings of the last ten years. No studies have evaluated the association between catch of the fishery fleet and amplitude and duration of the flooding and fishing effort in the Ucayali and Amazon rivers. Hydrological indices were based on the Amazon water stage taken at Iquitos gauge station in the last ten years. Hydrological indices and fishing effort were used as explanatory variables in a multiple linear regression to answer the question whether the factor responsible for the fluctuation in catch per guilds was the intensity of flooding or the severity of the draw-down period while accounting for fishing effort. This analysis was performed with index of the same year and index of the preceding year. The most significant variables were flood index of the same year and number of fishermen-trips. A positive influence of flooding on the omnivore group was evident in the Ucayali (p-value = 0.03) and Amazon (p-value = 0.001) rivers. However, this influence was negative (p-value = 0.03) on the detritivore group in the Ucayali River at high water which is interpreted as being due to reduced feeding places and stranding process. Number of fishermen-trips explains 90% and 96% of the variance of annual catches in the Ucayali and Amazon rivers, respectively. Additionally, six catch prediction models are presented.
