The Catfish Fishing in the Amazon Floodplain Lakes

Abstract

This study is about the spatial and temporal variability of the Hypophthalmus catfish fishery in the Amazonian floodplain lakes and the relationship among commercial CPUE, environmental and economic variables. The fishing productivity varies according to the fishing ground which varies due to the contribution of a set of variables. The most outstanding environmental variables are the Amazon River flow, the largescale ENSO and GITA events. This catfish productivity was related to the dynamics of the hydrological cycle, ENSO events and economic factors in Óbidos, mainly with economic variables in Santarém and the dynamics of sea surface temperature, ENSO events and economic factors in Monte Alegre. Regarding this fishing profitability, the main economic factors are the distance to the nearest buyer market location and boat types -ice storage capacity and fuel required. The present study is a contribution to the development of a more sustainable small-scale fishery management policy for Amazon and other floodplain regions around the world. To monitor and deepen understanding of this resource fishing dynamics, we strongly encourage additional studies to offer long-term fishery data set, analyze the fishermen behaviour with changes in the exploitation form and intensity in the floodplain lakes, and address other essential data such as use of floodplain, local community, land and vegetation cover as well as landscape changes.

Shark bycatch of the acoupa weakfish, Cynoscion acoupa (Lacèpede, 1801), fisheries of the Amazon Shelf

“…Cross-wavelet, coherence wavelet, and Redundancy Analysis (RDA) techniques were used to determine the relationship between catches and the variation in environmental parameters. The cross-wavelet analysis compares the wavelet spectra of two data series, and has been widely used in fishery research to relate fishing and environmental variables (Meńard et al, 2007;Polanco et al, 2011;Pinaya et al, 2018). This permits the detection of similarities between the local fluctuation of two time series and the estimation of the phase between these fluctuations.…”

“…The interpretation of the crossed and coherence wavelet vectors is based on the angle between the two study variables (see Torrence and Compo, 1998;Grinsted et al, 2004): (a) an angle of 0°indicates that the variables are in phase; (b) 45°i ndicates a difference of one eighth; (c) 90°indicates a difference of one quarter; (d) 135°indicates a difference of three eighths, and e) 180°indicates that the variables are in completely opposite phases. Wavelet, cross-wavelet, and coherence wavelet approaches are robust tools for the analysis of time series, and are widely used in geophysical, environmental, and fishery studies (Lan et al, 2012;Pinaya et al, 2018;Shuai et al, 2018). Wavelets are suitable for decomposing other functions in a manner comparable to the sine and cosine functions that form the basis for the Fourier transformation (Polikar, 2001).…”

How does climate change affect small scale fisheries? A case study of the Lower Amazon in Brazil

“…Pressure from fisheries, combined with environmental variability, are important determinants of the size of fish stocks, which means that a systematic understanding of environmental variability is fundamental to interpretation of fishery dynamics (Cruz et al, 2017; Isaac et al, 2016; Pinaya et al, 2018). Therefore, study of the effects of environmental changes on fish populations is essential for effective management of ecosystems targeted by fisheries and has become an increasingly important prerequisite for planning and implementation of strategies for administration of fishery resources (Cruz et al, 2017; Pinaya et al, 2018).…”

“…The hydrological cycle of the Amazon basin and variability in this cycle are associated strongly with climatic patterns such as the ENSO (El Niño Southern Oscillation) and variability in sea surface temperature of the Atlantic Ocean, which are important determinants of the region's fishery productivity (Barros et al, 2020; Castello et al, 2015; Cruz et al, 2017; Isaac et al, 2016; Pinaya et al, 2018). Given this, effects of environmental variables on the hydrological cycle of the Amazon basin must be understood, and in turn, how this affects the ecology of local fish species and productivity of local fisheries (Barros et al, 2020; Cruz et al, 2017; Gouveia et al, 2019; Pinaya et al, 2016, 2018).…”

“…In the Lower Amazon, only one study related fishery productivity systematically with environmental and economic variables, by considering temporal patterns, although it focused on only one group of fish, the long‐whiskered catfish Hypophthalmus spp. (known locally as long‐whiskered catfish or mapará in Portuguese; Pinaya et al, 2018). Findings of that study indicated that catches were related to dynamics of the hydrological cycle and sea surface temperatures, ENSO events, and economic factors.…”