Traces of oil in sea turtle feces.

In 2019, an oil spill hit the Brazilian Northeast coast causing impact to several ecosystems, including sea turtles' breeding and feeding areas. This study aimed to investigate whether sea turtles were impacted by this oil disaster, correlating the oil found inside feces with a sandy-oiled sample collected on the beach some days after the accident. The fecal samples were collected in the upper mid-littoral reef areas during three consecutive days in February 2020. The results suggested that sea turtles consumed algae contaminated by petroleum. Hydrocarbons composition of oil inside feces was similar to the sandy-oiled sample, suggesting they were the same. Lighter aliphatic and polycyclic aromatic compounds were missing, indicating both sandy-oiled and oil inside the feces had experienced significant evaporation prior to collection. Although the long-term damage is still unknown, the data are novel and relevant to support future research and alert authorities about the risks to sea turtles.

PAH residues and toxicity levels two years after an extensive oil spill on the northeast Brazilian coast.

The most extensive oil spill ever recorded in tropical oceans occurred between August 2019 and March 2020, affecting approximately 3000 km of the Brazilian coast. This study assessed the chemical contamination and toxicity of sediments collected from affected reef areas during two sampling surveys conducted 17 and 24 months after the peak of oil slick inputs. Our results indicated that neither PAH levels nor measured toxicity showed a significant contribution from the spilled oil, with concentrations and biological effects indistinguishable from those in unaffected areas. Similarly, no differences were observed between seasons. Furthermore, there was no discernible relationship between sediment toxicity results and the measured PAH concentrations. Therefore, while biological responses indicated toxicity in most assessed areas, these responses are likely related to other local sources. This evidence suggests a natural oil attenuation process contributing to local environmental recovery. Nonetheless, further investigation is needed for other areas affected by oil spills.

Cellular accumulation of crude oil compounds reduces the competitive fitness of the coral symbiont Symbiodinium glynnii.

Oil spill events in the marine environment can have a deleterious impact on the affected ecosystems, such as coral reefs, with direct consequences for their socioeconomic value. The mutualistic relationship between tropical corals and their dinoflagellate symbionts (Symbiodiniaceae) provide structural and nutritional basis for a high local biodiversity in oligotrophic waters. Here, we investigated effects of crude oil water-accommodated fraction on the competitive fitness of the model zooxanthellae species Symbiodinium glynnii. Results of laboratory essays demonstrate that crude oil carbon is incorporated into the cellular biomass with a concomitant change of δ13C isotopic value. Carcinogenic/mutagenic polycyclic aromatic hydrocarbons were identified in the culture media and were responsible for a linear reduction in population growth of S. glynnii, presumably related to energy relocation for DNA repair. Additionally, the experiments revealed that physiological effects induced by crude oil compounds are genetically inherited by the following generations under non-contaminated growth conditions, and induce a reduction in the competitive fitness to cope with other environmental parameters, such as low salinity. We suggest that the effects of crude oil contamination represent an imparing factor for S. glynnii coping with anthropogenic drivers (e.g. warming and acidification) and interfere with the delicate symbiont-host relationship of tropical corals. This is especially relevant in the coastal areas of northeastern Brazil where an oil spill event deposited crude oil on shallow water sediments with the potential to be resuspended to the water column by physical and/or biological activity, enhancing the risk of future coral bleaching events.

Mysterious oil spill along Brazil's northeast and southeast seaboard (2019-2020): Trying to find answers and filling data gaps.

Large amounts of crude oil were found along Brazil's northeast and southeast seaboard from August 2019 to January 2020. Petroleum companies and oil tankers reported no accidents previously or during this period. The stranded oil on Brazilian beaches looks like tar; it has solid aspect and is denser than seawater. Chemical characterization of this oil showed that light hydrocarbons were still present, increasing the probability of negative effects to coastal organisms and ecosystems upon release in the water column. Diagnostic ratios, chromatogram pattern, and percentage-weathering plots proved that the oil samples share the same oil source. This work provides data for future comparison with oil samples that will likely be found stranded along the Brazilian shoreline in the years to come, helping to understand long term issues associated with the mysterious oil spill that made landfall in late 2019.

Petroleum hydrocarbons in water from a Brazilian tropical estuary facing industrial and port development.

A fast paced industrial and port development has occurred at Suape Estuary, Northeast Brazil, but no information about hydrocarbon concentrations in water is available to this area. Considering that, the contamination level of Suape was determined by UV-Fluorescence in terms of dissolved and/or dispersed petroleum hydrocarbons (DDPHs), during wet and dry seasons. DDPHs ranged between 0.05 and 4.59 µg L(-1) Carmópolis oil equivalents and 0.01-1.39 µg L(-1) chrysene equivalents, indicating DDPHs close to a baseline contamination level. Some relatively high concentrations (>1 µg L(-1)) were probably associated with shipyard operations (hull paintings and ship docking), pollutants remobilization by dredging operations, occasional industrial discharges and oil derivatives released by vessels. DDPHs concentrations were lower in the wet season suggesting that the increased dilution rates caused by rainfall dominated upon the wet deposition of atmospheric combustion-derived PAHs process. Results in this study may be used as baseline to further studies in this area.