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

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 hereFunding for translation and publishing was provided by the Pro-Reitoria de Pesquisa e Pos-Graduacao (www.propesp.ufpa.br) and Fundacao de Amparo e Desenvolvimento da Pesquisa (www.portalfadesp.org.br) from Universidade Federal do Para (www.portal.ufpa.br). WHDP was supported by Brazilian Ph.D. Scholarships from the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior of Brazil (www.capes.gov.br). RBS was supported by Scholarship in Research Productivity PQ CNPq 308646/2013-4 from the Brazilian National Council for Scientific and Technological Development (www.cnpq.br). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific role of this author is articulated in the 'author contributions' sectionS

Fish production and CPUE per taxonomic family.

<p>Monthly averaged fish production (kg) and CPUE (kg·fisherman^-1·day^-1) per taxonomic family and fish caught and by artisanal driftnet fishery environment in the Lower Amazon.</p

Monthly fishery production by species in floodplain lakes.

<p>Monthly fishery production by species in floodplain lakes near the fishery grounds of Óbidos, Santarém and Monte Alegre, from January 1993 to December 2004. (HYP) <i>Hypophthalmus marginatus</i> and <i>H</i>. <i>edentatus</i>, (LIP) <i>Liposarcus pardalis</i>, (PRO) <i>Prochilodus nigricans</i>, (PIF) <i>Pimelodina flavipinnis</i>, (PAC) <i>Plagioscion</i> spp. and <i>Pachypops</i> spp. (PSE), <i>Pseudoplatystoma fasciatum</i> and <i>P</i>. <i>tigrinum</i>, (COL) <i>Colossoma macropomum</i>.</p

DCA analysis of the CPUE by target families.

<p>Graphic illustration of the first and second main component of the DCA analysis of the monthly average CPUE by target families caught in the Lower Amazon by fishery and environment. (HY) Hypophthalmidae, (PI) Pimelodidae, (SC) Sciaenidae, (PC) Prochilodontidae, (LR) Loricariidae, (SR) Serrasalmidae, (AN) Anostomidae, (CI) Cichlidae, (CL) Clupeidae, (DR) Doradidae; fishery environment in river (empty) and floodplain lake (full); the fishery of Óbidos (red), Santarém (blue), Monte Alegre (green). Axes 1 and 2 are the first and second main component of the data.</p

DCA for CPUE by fishery ground and environment.

<p>Graphic illustration of the DCA analysis for the monthly averaged CPUE in the Lower Amazon grouped by its fisheries grounds and the river or floodplain lakes environments.</p

Multiple regression model.

<p>Best significant results for the CPUE of each taxnomic family, fishing ground and fishing environment from multiple regression. Significant values p < 0.05 and 2 degrees of freedom.</p

RDA of the CPUE in relation to the environmental variables.

<p>Graphic illustration of the RDA analysis of the monthly average CPUE in the river (a) and floodplain lakes (b) of the Lower Amazon region for all taxonomic families with respect to the environmental variables. Black arrows are related to the taxonomic families while the red arrows represent the several environmental variables considered here. (HY) Hypophthalmidae, (PI) Pimelodidae, (SC) Sciaenidae, (PC) Prochilodontidae, (LR) Loricariidae, (SR) Serrasalmidae, (AN) Anostomidae, (CI) Cichlidae, (CL) Clupeidae, (DR) Doradidae, (ARD) the Amazon River discharge, (WL) the Amazon River level, (u, v) zonal and meridional components of the wind, (TEMP) surface temperature, (SPFH) specific humidity of the air, (RUNOF) surface runoff, (LHF) latent heat flux, (GITA) Inter-Hemispheric SST Gradient of the Atlantic, (NAO) North Atlantic Oscillation Index, (MEI) Multivariate Climatic Index of ENSO events.</p

Temporal variation in the average CPUE by fish family.

<p>Diagram showing temporal variation in the average CPUE by taxonomic family in the catches in the (a) Amazon River, and in (b) floodplain lakes in the Lower Amazon, from January 1993 to December 2004. (HY) Hypophthalmidae, (PI) Pimelodidae, (SC) Sciaenidae, (PC) Prochilodontidae, (LR) Loricariidae, (SR) Serrasalmidae, (AN) Anostomidae, (CI) Cichlidae, (CL) Clupeidae, (DR) Doradidae.</p

Dispersion diagram and correlations among the environmental variables.

<p>(ARD) Amazon River Discharge, (WL) Water Level, (RF) Rainfall, (u) Zonal Wind Component, (v) Meridional Wind Component, (TMPsfc) Surface Temperature, (TMIN2m) Air Temperature, (SPFH2m) Specific Humidity at 2 m height, (SWSoilM) Water Content of the Soil, (PEVPR) Potential Evaporation, (RUNOF) Runoff, (LHF) Latent Heat Flux, (SSTA) Sea Surface Temperature, (MEI) Multivariate ENSO Index, (GITA) Atlantic I<i>nter-Hemispheric Sea Surface Temperature Gradient</i>, (NAO) North Atlantic Oscillation, (AP) Continental Shelf of Amapá, (AZ) Continental Shelf of the Amazon, (PA) Continental Shelf of Pará.</p

ANOVA for CPUE by target family and year.

<p>Graphic illustration of the results of the ANOVA test for the average CPUE for fisheries in the river (above) and floodplain lakes (below) in the Lower Amazon, by taxonomic family and year. (XA) level of the factor, (a) family and (b) year.</p