Jurujuba Sound pore water and sediment Data - RJ - Brazil

The Jurujuba Sound is located within Guanabara Bay (Rio de Janeiro - Brazil), this overpopulated region probably may have contributed to the accumulation of chemical compounds in the sediments by diffuse sources (the Cachoeira and Icaraí rivers). Jurujuba Sound also supports a considerable area of mussel farms. In this research two main investigation approaches had been chosen, pore water and sediments nutrients. This work aims to indicate the characteristic distribution of the superficial sediment (pH, Eh, particular size, carbonate, organic matter and phosphorus, and nutrients present in pore-water (C, N, P) along Jurujuba Sound area. . The pH and Eh were measured in-situ using a Hanna Multiparameter probe. In the laboratory, nutrients in pore-ware water were measured by the colorimetric method with a KASUAKI UV / VIS spectrometer at different wavelengths for phosphate (and total phosphorous) (880 nm), nitrate (505 nm), nitrite (540 nm), and ammonium (630 nm). The grain size analysis was determined on a laser analyzer, carbonate was performed by mass difference. Spatial distribution maps were produced for each parameter, to assess nutrients spatial behavior and their relationships with other parameters. The results demonstrate high N and P concentrations in pore water, indicating the possible release of the relevant nutrient amount in the water column. The high rate of domestic effluent input (Confirmed by TOC/TN ratio) led to high nutrient levels in sediments and porewater, potential release from the bottom sea could cause fish mortality events and other toxic effects.