Carbonate system in the Cabo Frio upwelling.

The quantitative assessment of the carbonate system represents one of the biggest challenges toward the "Sustainable Development Goals" defined by the United Nations in 2015. In this sense, the present study investigated the Spatio-temporal dynamics of the carbonate system and the effects of the El Niño and La Niña phenomena over the Cabo Frio upwelling area. The physical characterization of the site was carried out through data on wind speed and sea surface temperature. Water samples were also collected during the oceanographic cruise onboard the Diadorim R/V (Research Vessel). From these samples, the parameters of absolute and practical salinity, density, pH, total alkalinity, carbonate, calcite, aragonite, bicarbonate dissolved inorganic carbon, carbon dioxide, partial pressure of carbon, calcium, and total boron were obtained. The highest average concentration of bicarbonate in S1 (2018 µmol/kg) seems to contribute to the dissolved inorganic carbon values (2203 µmol/kg). The values of calcite saturation state, aragonite saturation state, and carbonate were higher on the surface of each station (calcite saturation state = 4.80-5.48; aragonite saturation state = 3.10-3.63, and carbonate = 189-216 µmol/kg). The mean values of pH were similar in the day/night samples (7.96/7.97). The whole carbonate system was calculated through thermodynamic modeling with the Marine Chemical Analysis (AQM) program loaded with the results of the following parameters: temperature, salinity, total alkalinity, and pH parameters. This manuscript presents original data on the carbonate system and the "acidification" process influenced by the Cabo Frio upwelling, which directly depends on the El Niño and La Niña phenomena oscillations in the sea surface temperature.

Uncovering the Microbial Diversity of Two Exotic Calcareous Sponges.

Sponges-associated microorganisms play important roles in their health and ecology; consequently, they may be crucial in the successful adaptation of exotic species to novel environments. However, few studies have focused on the microbial diversity of exotic sponges, especially those with calcium carbonate spicules (class Calcarea). Therefore, this is the first in situ characterization of the microbiota of the exotic calcareous sponges Sycettusa hastifera and Paraleucilla magna. Our results suggest that S. hastifera has a more stable microbiota than P. magna, as there were no differences in its beta diversity among sampling sites. Conversely, P. magna showed significant differences in its microbial communities, perhaps related to its adhesion to artificial substrate and/or shellfish mariculture activities. Each sponge species presented a single dominant proteobacterial OTU potentially active in the nitrogen cycle, which could help sponge detoxification, especially in polluted areas where exotic species usually establish. Our results show the importance of assessing the microbial diversity to unveil host-microorganism relationships and suggest that these associated nitrogen-cycling microorganisms could favor the success of exotic sponges in new environments.

Assessment of toxicity of dissolved and microencapsulated biocides for control of the Golden Mussel Limnoperna fortunei.

Biological invasions currently pose major threats to ecosystems worldwide. Invasive bivalves such as the Golden Mussel Limnoperna fortunei can act as 'environmental engineers', altering biogeochemistry, reducing biodiversity, and literally changing the landscape of aquatic environments. The risk that this mussel will invade the Amazon basin is a great concern for environmental authorities, especially because no efficient control methods presently exist. In this study, we tested new microencapsulated chemicals, along with the traditional dissolved chlorine and KCl, as alternatives to control L. fortunei infestation in industrial and water supply plants along rivers. Because these bivalves can close their valves when they sense toxic substances in the water, microencapsulation has improved the effectiveness of the chemicals in controlling L. fortunei, reducing variation in the application and increasing toxicity compared to dissolved chemicals. Microencapsulation should be seriously considered as an alternative to replace hazardous chlorine.

137Cs in marine samples from the Brazilian southeastern coastal region.

The present work presents the results of (137)Cs concentration in seawater, fish and sediments samples collect in 11 sampling points, crossing the Brazilian Southeastern coastal region, from Vitória (ES) to Santos (SP), on a routine basis from 1997 to 2002. This monitoring program was carried out by the Instituto de Radioproteção e Dosimetria (IRD/CNEN/MCT), in cooperation with the Instituto de Estudos do Mar Almirante Paulo Moreira (IEAPM/Brazilian Navy), aiming at determining artificial radionuclides in marine samples. Additionally to the (137)Cs results, (90)Sr concentrations in fish samples from 1998 to 2002 are also reported. The (137)Cs in seawater follows a lognormal distribution, with a geometric mean of 1.8 Bq m(-3) and a geometric standard deviation of 1.4 (n=54), decay corrected to June/2002. For (137)Cs levels in fish samples a geometric mean of 0.19 Bq kg(-1) and a geometric standard deviation of 2.9 (n=39), decay corrected to June/2002, with a range of 0.03 to 1.7 Bq kg(-1), were obtained. Based on the (137)Cs mean concentration in fish as well as in seawater, a transfer factor of 1 x 10(2) was calculated, which is quite in agreement with the recommended value found in the Safety Report Serie 19.