Augusto Cesar

Assessment of microplastic toxicity to embryonic development of the sea urchin Lytechinus variegatus (Echinodermata: Echinoidea).

Apart from the physiological impacts on marine organisms caused by ingesting microplastics, the toxicity caused by substances leaching from these particles into the environment requires investigation. To understand this potential risk, we evaluated the toxicity of virgin (raw) and beach-stranded plastic pellets to the development of embryos of Lytechinus variegatus, simulating transfers of chemical compounds to interstitial water and water column by assays of pellet-water interface and elutriate, respectively. Both assays showed that virgin pellets had toxic effects, increasing anomalous embryonic development by 58.1% and 66.5%, respectively. The toxicity of stranded pellets was lower than virgin pellets, and was observed only for pellet-water interface assay. These results show that (i) plastic pellets act as a vector of pollutants, especially for plastic additives found on virgin particles; and that (ii) the toxicity of leached chemicals from pellets depends on the exposure pathway and on the environmental compartment in which pellets accumulate.

Occurrence of pharmaceuticals and cocaine in a Brazilian coastal zone.

The present study determined environmental concentrations of pharmaceuticals, cocaine, and the main human metabolite of cocaine in seawater sampled from a subtropical coastal zone (Santos, Brazil). The Santos Bay is located in a metropolitan region and receives over 7367m(3) of wastewater per day. Five sample points under strong influence of the submarine sewage outfall were chosen. Through quantitative analysis by LC-MS/MS, 33 compounds were investigated. Seven pharmaceuticals (atenolol, acetaminophen, caffeine, losartan, valsartan, diclofenac, and ibuprofen), an illicit drug (cocaine), and its main human metabolite (benzoylecgonine) were detected at least once in seawater sampled from Santos Bay at concentrations that ranged from ng·L(-1) to μg·L(-1). In light of the possibility of bioaccumulation and harmful effects, the high concentrations of pharmaceuticals and cocaine found in this marine subtropical ecosystem are of environmental concern.

Ecological relevance of Sentinels' biomarker responses: A multi-level approach

In response to the need for more sensitive and rapid indicators of environmental quality, sublethal effects on the lowest levels of biological organization have been investigated. The ecological relevance of these responses assumes a prevailing role to assure effectiveness as indicator of ecological status. This study aimed to investigate the linkages between biomarker responses of caged bivalves and descriptive parameters of macrobenthic community structure. For this purpose a multi-level environmental assessment of marine and estuarine zones was performed in São Paulo coast, Brazil. Multivariate analysis was applied to identify linkages between biological responses and ecological indices, as well as to characterizing the studied stations. Individuals of the marine mussel Perna perna caged along Santos Bay showed signs of oxidative stress, lysosomal membrane destabilization, histological alterations and reduced embryonic development. The estuarine oyster Crassostrea rhizophorae caged along Santos Port Channel showed alterations on biotransformation enzymes and antioxidant system, DNA damage and lysosomal membrane destabilization. The benthic community analysis showed reduced richness and diversity in the same areas of the Santos bay and estuary where biomarker responses were altered. Our results revealed that xenobiotics are inducing physiological stress, which may lead to changes of the benthic community structure and deterioration of the ecological status over time. Integrating biomarker responses and ecological indexes improved certainty that alterations found at community level could be related to xenobiotic as stressors, which was very useful to improve the discriminatory power of the environmental assessment.

Environmental assessment of dredged sediment in the major Latin American seaport (Santos, São Paulo-Brazil): an integrated approach.

This work offers an environmental assessment of a dredged sediment disposal area in Santos bay, situated on the central coast of the São Paulo State, Brazil. Sediment quality was evaluated through physicochemical analysis and toxicity tests of sediments collected in the disposal site and adjacent area. The physicochemical characterization of the sediments involved grain size distribution, concentrations of polycyclic aromatic hydrocarbons (PAHs), chlorinated and aromatic hydrocarbons, polychlorinated biphenyls (PCBs), pesticides, phthalates, metals and nutrients. Acute and chronic toxicity tests were employed, using amphipods (Tiburonella viscana) and sea urchins (Lythechinus variegatus), respectively. Results revealed toxicity by all the methods applied here, suggesting that the area of disposal of dredged material is significantly altered with respect to sediment quality and probably capable of generating deleterious effects on the local biota. Aiming to elucidate the association between the distinct environmental variables and the biological effects measured in laboratory, Factor Analysis was performed. Results revealed that despite most contaminant concentrations were found below the limits established by Brazilian legislation, biological effects were related to metals (chronic toxicity) and organic compounds (acute toxicity). The application of multivariate analysis proved to be particularly useful to assess and interpret the results in an integrated way, particularly due to the large number of parameters analyzed in environmental assessments, and should be applied in future studies.

Improved sea-urchin embryo bioassay for in situ evaluation of dredged material

Sediments usually contain many contaminants derived from human activities. In case of dredging activities, these sediment-bound contaminants arise following the excavation and remobilization of sediments. Previous studies have used different species of clam, crabs, lugworms, etc. for the evaluation of dredged material in situ, but there are not studies that use acute bioassays for these purposes. The sea-urchin embryo bioassay has been chosen to characterize biological effects in situ in two ports of the southwest of Spain, the Port of Huelva and the Port of Cadiz. The sea-urchin embryo bioassay has been adapted for in situ evaluation of seawater quality in coastal areas, however, they are necessary for further improvements to take into account differences of temperature between sites. This temperature variation is one of the principal reasons (other than pollution) of larval mortality and the slow down in the growth rate of the urchin. In the present study a bioassay was conducted in both field and laboratory conditions, in order to compare the effects in situ with the effects under controlled conditions of temperature, salinity and oxygen dissolved. Results showed a good correlation between samples obtained in situ and in the laboratory, but in the field the percentage of normal pluteus larvae is less than under laboratory conditions.

Bioaccumulation of Polycyclic Aromatic Hydrocarbons and Mercury in Oysters (Crassostrea rhizophorae) from Two Brazilian Estuarine Zones

Nowadays, organisms are increasingly being used in biomonitoring to assess bioavailability and bioaccumulation of contaminants. This approach can use both native and transplanted organisms in order to accomplish this task. In Brazil, most of the studies related to bioaccumulation of contaminants in oysters deal with metals. The present work employs this kind of test in Brazilian coastal estuaries (Santos and Paranagua) to evaluate total mercury and polycyclic aromatic hydrocarbon contamination in sediments and oysters (native and caged Crassostrea rhizophorae). The methodologies employed were based on known USEPA methods. Results have shown a significant contamination in Santos sediments and consequent bioavailability of organisms. Paranagua sediments presented lower contamination in sediments, but native oysters were able to accumulate total Hg. The experiments done with caged oysters did not show significant bioaccumulation of Hg and PAHs in the Paranagua site, but proved to be an excellent tool to assess bioavailability in the Santos estuary since they were able to bioaccumulate up to 1,600% of total PAH in the samples from the inner part of this estuary when compared to control organisms. Multivariate statistical analyses employed to these results have separated the sites evaluated and the most contaminated samples from the least contaminated.

What is the best endpoint for assessing environmental risk associated with acidification caused by CO 2 enrichment using mussels

Carbon capture and storage is a technology that has been widely determined to be one of the best choices for the short-term reduction of atmospheric CO2 emissions. The aim of this study was to analyze the effects of CO2 enrichment in the ocean on the mussel species Mytilus galloprovincialis using three different endpoints: mortality, embryo-larval development, and neutral red retention time assays (NRRT). Acute effects were found to be associated with a pH values of 6.0 while citotoxity effects and embryo-larval development were associated with a pH value of 7.0. The NRRT assay and embryo-larval development can be recommended as good endpoints for assessing the environmental risk associated with acidification by CO2 enrichment because they provide sensitive responses on the effects of changes in seawater pH on mussels in a short period of time. Moreover, this study may support policymakers in finding appropriate solutions for the conservation of marine ecosystems.

Assessment of the environmental impacts of ocean acidification (OA) and carbon capture and storage (CCS) leaks using the amphipod Hyale youngi

This study aims to ascertain the effects of CO2 induced water acidification and leaks from Carbon Capture and Storage activities on the South American amphipod Hyale youngi. A 10-day acute toxicity test was performed using sediments from two sites located inside the Santos Estuarine System. They were subjected to five pH treatments (8.1, 7.6, 7.0, 6.5, and 6.0). Metals (Cd, Cu, Cr, Pb, Ni and Zn) and the metalloid As were analyzed to determine the influence of their acidification-related mobility on the amphipods mortality. The results showed that mortality becomes significant when compared to control in pH 6.5 in the Canal de Piaçaguera sediment (contaminated) and at pH 6.0 in Ilha das Palmas sediment (reference).

Assessing the influence of ocean acidification to marine amphipods: A comparative study

CO2 increases in the ocean may occur both by the capacity of CO2 exchanges with its dissolved form between atmosphere and surface seawater as well by CO2 leaks during the carbon capture and storage (CCS) process. The decrease in seawater pH may result in a reduction in the concentration of both hydroxide and carbonate (OH- and CO32-). The main aim of this work is to conduct an ecotoxicology comparative survey using two amphipod species from Europe and Brazil exposed to different acidification (CO2) scenarios. For it, an integrative approach based on the weight of evidence was used for comparative proposes to identify the effects on the amphipods association with the acidification and with the related mobility of metals. The results demonstrate that the Ampelisca brevicornis species is more sensitive to pH reductions than the Hyale youngi species. Furthermore, this study has demonstrated that the CO2 enrichment in aquatic ecosystems would cause changes on the mobility of certain metals (Zn, Cu and As). The results of Principal Component Analysis (PCA) showed that the dissolved Zn in overlying water was strongly correlated with the decrease in the pH and was associated with increased toxicity of the sediment to the exposed organisms, mainly for the A. brevicornis species from Spain. Nevertheless, similar results were found in relation to the mortality of amphipods in low pH values for all sediment tested. Concluding, it is highlighted the importance of comparative studies in different types of environment and improve the understood of the risks associated with the ocean acidification.

Ecotoxicological assessment of four pharmaceuticals compounds through acute toxicity tests

In this study, we evaluated acute toxicity of four different pharmaceutical compounds: 17 α-ethinylestradiol (EE2), fluoxetine, diclofenac and ibuprofen to Daphnia similis. The average values of EC50 were 1.63 mg/L to the 17α-ethinylestradiol (EE2), 4.41 mg/L to the fluoxetine, 46.0 mg/L to the diclofenac and 97.0 mg/L to the ibuprofen. The effects of these drugs, in particular those caused to aquatic biota, still unknown especially at low concentrations in a range from ng/L up to mg/L.