Mapeamento e análise temporal das variáveis físico-ambientais que influenciam a produtividade de camarão rosa Penaeus subtilis na plataforma continental amazônica.

Abstract

The Penaeus subtilis, commonly known as pink shrimp is a species widely captured in the northern region of Brazil, and its capture is prominent in the industrial fleet of bottom trawling. The pink shrimp capture area on the north coast extends from the mouth of the Parnaíba River (PI) to the border between the state of Amapá and French Guiana. This study presents a time series analysis, between the years 2000 and 2004, of the relative abundance of pink shrimp and its ecological relation ships with the environment (physical and environmental). In the work, remote sensing and Geographic Information System techniques were used. From the applied methodology it waspossible to map the spatial distribution and the abundance of pink shrimp in the Amazon continental shelf. The database provided observations of 8383.57 hours of trawling, trips with a total production of 39.991 tons and an average of 5683 kg/hour of trawling. Pink shrimp relative abundance data (weight ratio/ hour of trawling) were analyzed with respect to abiotic parameters such as river flow, salinity, temperature and current at 35 m depth and geomorphological characteristics of the substrate of the Amazonas continental. The relative abundance series of the species presents significant interannual variations (r2 = 0.57) and the data climatology demonstrates a maximuminthe capture between February and March and a minimum in October. The results demonstrate that these seasonal fluctuations in the pink shrimp capture follow variations in the Amazon plume, but may also be related to the current variability in the region, which, in turn, varies in antiphase in relation to the Catch per Unit Effort series. Thespatial distribution of the analyzed parameters and the relative abundance of pink shrimp show that the zones with the greatest capture are found to the northwest of the platform, in front of the Amapá coast, in the strip where the substrate is from muddysand with moderate slope in the Northeast direction. This main capture zone occurs at the edge of the main flow axis of the North Brazil Current and it is maximum when the Amazon plume reaches the area.