Ichthyofauna as bioindicator of environmental quality in an industrial district in the amazon estuary, Brazil.

Ap Viana,F Lucena Frédou

doi:10.1590/1519-6984.16012

Abstract

The objective of the present study was to describe the ecological status of ichthyofauna in an industrial district (Pará river, Amazon estuary), through the use of different environmental descriptors. To evaluate the impacts of the industrial area and cargo terminal, three areas were considered: Zone 1 (maximum impact), Zone 2 (median impact) and Zone 3 (low impact). A total of 77 species were captured. Differences in the composition of the ichthyofauna were recorded between Zones and environments (main channel and tidal channel). The ecological indices revealed clear evidence of the impact of the industrial hub and cargo terminal on the fish communities. In Zone 1, there was a reduction in the number of feeding groups (in the main channel) and larger fish and the Shannon diversity index and Margalef's richness were also significantly lower. The multivariate analysis separated the different Zones clearly into three groups, indicating marked differences in the levels of contamination in the different parts of the study area.

Highlights

The Amazon estuary is the oceanic outlet of the World’s largest hydrographic basin, with a total discharge equivalent to approximately one sixth of that of all the rivers in the World combined, containing one fifth of all the freshwater released into the planet’s oceans (Martinelli et al, 1989)
A total of 1.708 fish specimens belonging to 77 species, 27 families and 10 orders were captured. Considering both main channel and tidal channel, 23 species were captured in Zone 1, in Zone 2, and in Zone 3 (Table 1)
Accessory species predominated in Zone 3, in both main (44%) and tidal channel (62.7%), while occasional species were common in all Zones, principally the main channel (Table 1)

Summary

Introduction

The Amazon estuary is the oceanic outlet of the World’s largest hydrographic basin, with a total discharge equivalent to approximately one sixth of that of all the rivers in the World combined, containing one fifth of all the freshwater released into the planet’s oceans (Martinelli et al, 1989). Within the Amazon estuary, more precisely in the estuary of the Pará River, an important industrial hub is located, where activities include the processing of kaolin, alumina and aluminum for export. These processes produce residues which may liberate substances with significant impacts on the quality of the water (Rubio and Tessele, 2002). The principal sources of risk include leaks from tanks and pipelines, accidental spills of toxic substances and the overflowing of residue sedimentation pools, all of which have been recorded in the study area since the establishment of the industrial installations (Lima et al, 2011)

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