Multispecies Fisheries in the Lower Amazon River and Its Relationship with the Regional and Global Climate Variability

Abstract

This paper aims to describe the spatial-temporal variability in catch of the main fishery resources of the Amazon River and floodplain lakes of the Lower Amazon, as well as relating the Catch per Unit of Effort with anomalies of some of the Amazon River, atmosphere and Atlantic Ocean system variables, determining the influence of the environment on the Amazonian fishery resources. Finfish landings data from the towns and villages of the Lower Amazon for the fisheries of three sites (Óbidos, Santarém and Monte Alegre), were obtained for the period between January 1993 and December 2004. Analysis of variance, detrended correspondence analysis, redundancy analysis and multiple regression techniques were used for the statistical analysis of the distinct time series. Fisheries production in the Lower Amazon presents differences between the Amazon River and the floodplain lakes. Production in the Amazon River is approximately half of the one of the floodplain lakes. This variability occurs both along the Lower Amazon River region (longitudinal gradient) and laterally (latitudinal gradient) for every fishing ground studied here. The distinct environmental variables alone or in association act differently on the fishery stocks and the success of catches in each fishery group studied here. Important variables are the flooding events; the soil the sea surface temperatures; the humidity; the wind and the occurence of El Niño-Southern Oscillation events. Fishery productivity presents a large difference in quantity and distribution patterns between the river and floodplain lakes. This variability occurs in the region of the Lower Amazon as well as laterally for each fishery group studied, being dependent on the ecological characteristics and life strategies of each fish group considered here.

Simultaneous abrupt shifts in hydrology and fish assemblage structure in a floodplain lake in the central Amazon

“…In addition, fishing pressure41 and deforestation42 in the central Amazon could have contributed to reduced resilience of certain fish stocks (e.g., large species with relatively long generation times, represented in our study by EL and PL life history strategies) to hydrological changes. Because central Amazon fisheries preferentially target large species43, it will be difficult to quantify effects of hydrology and fishing on fish populations and assemblages separately. Continuous monitoring and analysis of longer time series are needed to disentangle effects caused by more frequent occurrence of extreme drought, persistent changes in hydrology, fisheries and other extrinsic as well as intrinsic drivers of fish assemblage structure.…”

The Digestive Function of Pseudoplatystoma punctifer Early Juveniles Is Differentially Modulated by Dietary Protein, Lipid and Carbohydrate Content and Their Ratios

“…Pseudoplatystoma punctifer is a piscivorous migratory catfish native to the Amazon basin in Bolivia, Brazil, Colombia, Ecuador, Peru, and Venezuela [ 19 ]. Given its high flesh quality, size (up to 1.40 m total length, TL), and commercial value, P. punctifer is highly appreciated in the region and suffers from high fishing pressure [ 20 , 21 ], what has led to the development of the aquaculture of this species. However, a high incidence of cannibalism and a low acceptability of compound diets at weaning have been responsible for low survival during early life stages [ 22 , 23 ], hence limiting the success of its commercial farming.…”

Stock assessment of Prochilodus nigricans (Actinopterygii: Characiformes: Prochilodontidae) using two distinct algorithms, in the context of a small-scale Amazonian fishery

“…Subsequently, the fishers were asked questions and each question was two times repeated and the coincidence between answers was checked aiming to assure a complete understanding. Taking into account that there is a recognized seasonal pattern of catch and effort associated with the hydrological cycle (Castello et al 2015, Pinaya et al 2016, annual means of these parameters were used into the model. Initial questions were designed to validate the knowledge base of the fisher, as well as to examine fishing locations, gear type, and total catch: This was followed by questions concerning the perception of the importance of fishing, as well as questions pertaining to perceptions of changes in catch rate over time (catch rate of the present year, catch rate of the previous year, catch rate at the time of pristine stocks) and recovery time for fish stocks:…”