The most extensive oil spill registered in tropical oceans (Brazil): the balance sheet of a disaster

Forensic Geochemistry Reveals International Ship Dumping as a Source of New Oil Spill in Brazil's Coastline (Bahia) in Late 2023

In the present study, we applied forensic geochemistry to investigate the origin and fate of spilled oils like tarballs stranded at the beaches of Bahia, in northeastern Brazil, in September 2023, based on their fingerprints. Saturated and aromatic compounds were assessed by gas chromatography, and the oceanic surface circulation patterns were deciphered to determine the geographic origin of the spill. Contamination by petroleum represents an enormous threat to the unique, species-rich ecosystems of the study area. The geochemical fingerprint of the oil spilled in 2023 did not correlate with those of previous events, including the one in 2019, the one in early 2022 in Ceará, and an extensive spill across the Brazilian Northeast in late 2022. However, the fingerprint did correlate with crude oils produced by Middle Eastern countries, most likely Kuwait. The oil of the 2023 spill had a carbonate marine origin from early mature source rocks. These findings, together with the moderate weathering of the 2023 tarballs and the ocean circulation patterns at the time of the event, indicate that the oil was discharged close to the shore of Brazil, to the east or southeast of Salvador, by a tanker on an international route in the South Atlantic.

The impact of chronic and acute problems on sea turtles: The consequences of the oil spill and ingestion of anthropogenic debris on the tropical semi-arid coast of Ceará, Brazil

Sea turtle mortality is often related to materials that reach the coast from different anthropic activities worldwide. This study aimed to investigate whether sea turtle mortality was related to older marine problems, such as solid waste, or one of the largest oil spill accidents on the Brazilian coast, that occurred in 2019. We posed three questions: 1) Are there solid residues in the digestive tract samples, and which typology is the most abundant? 2) Can meso‑ and macro-waste marine pollutants cause mortality? 3) Is the dark material found really oil? A total of 25 gastrointestinal content (GC) samples were obtained, of which 22 ingested waste of anthropogenic origin and 18 were necropsied. These 22 samples were obtained during or after the 2019 oil spill, of which 17 specimens were affected, making it possible to suggest oil ingestion with the cause of death in the animals that could be necropsied. Macroscopic data showed that the most abundant solid waste was plastic (76.05 %), followed by fabrics (12.18 %) and oil-like materials. However, chemical data confirmed only three specimens with oil levels ranging from remnants to high. It was possible to infer possible causes of death in 16 of the total 18 necropsied cases: Most deaths were due to respiratory arrest (62.5 %), followed by pulmonary edema (12.5 %), cachexia syndrome (12.5 %), circulatory shock (6.25 %), and head trauma (6.25 %), which may have been caused by contact with solid waste, oil, or both. The study showed that not all dark material found in the GCs of turtles killed in oiled areas is truly oil, and in this sense, a chemical analysis step to prove the evidence of oil must be added to international protocols.

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.

Thermal conversion of irradiated LLDPE waste into sustainable sponge-like compounds: a novel approach for efficient trace-level oil-water removal

The newest method for recycling waste linear low-density polyethylene (LLDPE) is the thermo-catalytic degradation technique known as catalytic pyrolysis. Typically, it is limited by 500-800 °C high temperatures. Catalytic pyrolysis releases toxins and forms harmful carbonized char. The current study is based on exposing wasted LLDPE to different gamma irradiation doses and then pyrolysis in castor oil (150-300 °C). The output product of Ir-(rLLDPE) is turned into another compound with a new structural architecture (sponge-like). SEM analysis confirms conversion, showing sponge-like spicules and layers. Ir-(rLLDPE) is sponge-like with a soft, malleable, absorbent texture. The DSC demonstrates altered thermal properties, with a melting point at 121 °C splitting into two peaks (endothermic at 117 °C and exothermic at 160 °C). The exothermic peaks signify the curing process of the sponge-like material. Ir-(rLLDPE) is assessed as an adsorbent for aqueous oils and solvents. The study examines irradiation doses, pyrolysis temperature, and time on adsorbent capacity. The oil removal obeys the Langmuir isotherm with monolayer adsorption, with a maximum adsorption capacity of 24.75 g/g of waste oil and 43 g/g of 1,1,2,2-tetrachloroethane. Squashing maintains adsorption after 20 reuses. Data shows sponges effectively clean marine oil spills and solvents.

The role of habitat heterogeneity and timescales on the recovery of reef epifaunal communities affected by a massive oil spill in the tropics

From August 2019 to January 2020 the Brazilian Coast was impacted by the largest oil spill in the Tropical oceans ever since. Paiva Beach, one of the most preserved sandy beaches in the northeast tropical Brazilian coast, was among the most affected regions by the oil spill in October 2019. This area has important reef systems that harbor abundant macroalgal assemblages with very diverse epifaunal communities. The present study aims to evaluate the impacts of the 2019 oil spill on epifauna associated with the seaweed species Jania capillacea and Penicillus capitatus collected in Paiva Beach from July 2019 to October 2022, and use the interaction macroalgae/epifauna/timescale as a proxy to quantify the effects of oil spills on communities structure and recovery. The epifauna of both algae did not suffer severe changes in abundance immediately after the spill, however, the abundance of taxa like echinoderms, sea spiders (Pycnogonida) and peracarid crustaceans dropped during or soon after the event, whereas others, like sabellid worms, had strong increase in abundance, possibly related to the spill. Both phytal assemblages also had distinct temporal patterns in species diversity and abundance, the last being strongly correlated to amphipod abundance for some taxa. The epifauna of J. capillacea had a short-term tendency of decrease in taxonomic diversity, whereas the epifaunal communities of P. capitatus gained a few taxa in the months immediately after the disaster. The diversity profiles of both communities returned to pre-spill conditions a few months later, with a slower abundance recovery in J. capillacea. Local environmental characteristics like landscape heterogeneity, connectivity with other environments, and critical-species (mainly amphipods) were possibly the main buffering factors for the phytal communities after the oil spill.

Impact of climate change and anthropogenic activities on aquatic ecosystem - A review

All living things depend on their natural environment, either directly or indirectly, for their high quality of life, growth, nutrition, and development. Due to the fast emissions of greenhouse gases (GHGs), the Earth's climate system is being negatively impacted by global warming. Stresses caused by climate change, such as rising and hotter seas, increased droughts and floods, and acrid waters, threaten the world's most populated areas and aquatic ecosystems. As a result, the aquatic ecosystems of the globe are quickly reaching hazardous conditions. Marine ecosystems are essential parts of the world's environment and provide several benefits to the human population, such as water for drinking and irrigation, leisure activities, and habitat for commercially significant fisheries. Although local human activities have influenced coastal zones for millennia, it is still unclear how these impacts and stresses from climate change may combine to endanger coastal ecosystems. Recent studies have shown that rising levels of greenhouse gases are causing ocean systems to experience conditions not seen in several million years, which may cause profound and irreversible ecological shifts. Ocean productivity has declined, food web dynamics have changed, habitat-forming species are less common, species ranges have changed, and disease prevalence has increased due to human climate change. We provide an outline of the interaction between global warming and the influence of humans along the coastline. This review aims to demonstrate the significance of long-term monitoring, the creation of ecological indicators, and the applications of understanding how aquatic biodiversity and ecosystem functioning respond to global warming. This review discusses the effects of current climate change on marine biological processes both now and in the future, describes present climate change concerning historical change, and considers the potential roles aquatic systems could play in mitigating the effects of global climate change.

Tarballs on the Brazilian coast in late 2022 sustain Lepas anatifera Linnaeus, 1758 (Crustacea: Cirripedia): Occurrence and risk of petroleum hydrocarbon ingestion

Since the 2019 oil spill on the northeastern coast of Brazil, oil materials have washed up on the beaches. A characteristic of the recent oil spill that began in late August was that some of the oiled material, such as tarballs, contained the goose barnacle species Lepas anatifera (Cirripedia, Lepadomorpha), which is well-known for its cosmopolitan distribution and wide occurrence in the oceans. The findings of this study provide information on the occurrence and contamination of petroleum hydrocarbons in animals adhered to the surfaces of tarballs sampled from beaches in the Brazilian states of Ceará and Rio Grande do Norte, between September and November 2022. The size of the barnacles varied from 0.122 to 2.20 cm, suggesting that the tarballs had been floating in the ocean for at least a month. All groups of L. anatifera collected from the tarballs had polycyclic aromatic hydrocarbons (PAHs) present (∑21PAHs from 476.33 to 3816.53 ng g-1). In comparison to high-molecular-weight PAHs, which are primarily from pyrolytic sources, low-molecular-weight PAHs, such as naphthalene and phenanthrene, which are mostly related to petrogenic sources, were shown to be more abundant. In addition, dibenzothiophene, which is exclusive of petrogenic origin, was found in all samples (30.74-537.76 ng g-1). The aliphatic hydrocarbons (AHs): n-alkanes, pristane, and phytane were also found and displayed petroleum characteristics. These results highlight the danger of increasing the absorption of petrogenic PAHs and AHs by organisms that use tarballs as substrates. L. anatifera is a crucial component of the food chain because many animals such as crabs, starfish, and gastropods consume it.

A custom, low-cost, continuous flow chamber built for experimental Sargassum seaweed decomposition and exposure of small rodents to generated gaseous products

Since 2011, Sargassum events have increased in frequency along the Caribbean and Atlantic coasts. The accumulation and decomposition of large amounts of Sargassum seaweed on beaches pose socio-economic, ecological, and health risks due to the emission of hydrogen sulfide (H2S), methane, and ammonia. However, limited research exists on the emission processes and the health effects of subchronic and chronic exposure to low levels of H2S. Additionally, the absence of emission factor data for Sargassum decomposition on-site makes health risk assessments challenging. This study aimed to create a custom chamber to simulate real-world Sargassum decomposition, exposing experimental animals to the generated gases. Metal content was analyzed, and emission rates were estimated in a controlled environment. The decomposition-exposure system replicated reported environmental gas emissions from the Caribbean region, except for NH3. H2S bursts were observed during the decomposition process at intervals of 2-10 days, with higher frequency associated with larger masses of decomposing Sargassum. The decomposed gas was transferred to the exposure chamber, resulting in an 80-87% reduction in H2S concentration. The maximum H2S emission was 156 ppm, with a concentration ranging from 50.4 to 56.5 ppm. An estimated emission rate of 7-8 g/h for H2S was observed, and significant levels of lead, arsenic, and aluminum were found in beached Sargassum from the northeast coast of Brazil. This study's developed model provides an opportunity to investigate the effects and risks to human health associated with exposure to gases produced during the environmental decomposition of Sargassum seaweed.

The Impact of Highly Weathered Oil from the Most Extensive Oil Spill in Tropical Oceans (Brazil) on the Microbiome of the Coral Mussismilia harttii

In 2019, the largest oil spill ever recorded in tropical oceans in terms of extent occurred in Brazil. The oil from the spill was collected directly from the environment and used in an exposure experiment with the endangered reef-building coral Mussismilia harttii. The treatments of the experiment were control (without oil), 1% oil, 2.5% oil, and direct contact of coral with oil. The most abundant hydrocarbon in the seawater of the experiment was phenatrene, which is toxic to corals. However, overall, the concentration of PAHs was not very high. The analysis of the maximum photosynthetic capacity of Symbiodiniaceae dinoflagellates showed a small impact of oil on corals, mainly on the contact treatment. However, coral microbiomes were affected in all oil treatments, with the contact treatment showing the most pronounced impact. A greater number and abundance of stress-indicating and potentially pathogenic bacteria were found in all oil treatments. Finally, this highly weathered oil that had lain in the ocean for a long time was carrying potentially coral-pathogenic bacteria within the Vibrionaceae family and was able to transmit some of these bacteria to corals. Bacteria within Vibrionaceae are the main causes of disease in different species of corals and other marine organisms.

Perceptions about massive environmental impacts: a Brazilian study case

The year 2019 brought three such impacts of high socio-environmental proportions in Brazil: the dam collapse in Brumadinho, oil spills on the coast, and fires in the Amazon. We investigated the Brazilian population's perceptions of the country's overall environmental situation, the degree to which Brazilians felt affected by these impacts considering personal and social factors, and the entities they held responsible for these disasters. Through Facebook's social media networks, we disseminated structured online surveys for Brazilian citizens above 18 years. Educational background explained how much the 775 respondents felt affected by the three evaluated events. Age was an explanatory factor for the degree to which the respondents felt affected by the dam collapse, and proximity to the disasters, while income levels were for the dam collapse and the fires in the Amazon. The government, criminal activity, and private companies were considered to be the main responsible for these three impacts. This perception reflects the series of changes in the country's environmental laws and protections that threaten biodiversity and the environment.

Genomic and phenotypic features of Acinetobacter baumannii isolated from oil reservoirs reveal a novel subspecies specialized in degrading hazardous hydrocarbons

The genus Acinetobacter encompasses biotechnologically relevant species and nosocomial pathogens. In this study, nine isolates recovered from different oil reservoir samples showed the ability to grow with petroleum as the only carbon source and possessed the ability to emulsify kerosene. The whole genomes of the nine strains were sequenced and analyzed. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values of all strains were compared to the reference strains, and the results were below the reference values (<97.88 and 82, respectively), suggesting that the isolates belong to a new subspecies of Acinetobacter baumannii. The name Acinetobacter baumannii oleum ficedula is proposed. A comparison of the whole genome repertoire of 290 Acinetobacter species indicated that the strains in this study resemble non-pathogenic Acinetobacter strains. However, the new isolates resemble A. baumannii when comparing virulence factors. The isolates in this study carry many genes involved in hydrocarbon degradation, indicating the potential to degrade most toxic compounds listed by environmental regulatory agencies such as ATSDR, EPA, and CONAMA. In addition, despite the absence of known biosurfactant or bioemulsifier genes, the strains showed emulsifying activity, suggesting the presence of new pathways or genes related to this process. This study investigated the genomic, phenotypic, and biochemical features of the novel environmental subspecies A. baumannii oleum ficedula, revealing their potential to degrade hydrocarbons and to produce biosurfactants or bioemulsifiers. Applying these environmental subspecies in bioaugmentation strategies sheds light on future approaches to bioremediation. The study shows the importance of genomic analysis of environmental strains and their inclusion in metabolic pathways databases, highlighting unique enzymes/alternative pathways for consuming hazardous hydrocarbons.

Severe ecological impacts caused by one of the worst orphan oil spills worldwide

Orphan oil spills pose a severe risk to ocean sustainability; however, they are understudied. We provide the first synthetic assessment of short-term ecological impacts of the most extensive oil spill in tropical oceans, which affected 2900 km of Brazil's coastline in 2019. Oil ingestion, changes in sex ratio and size of animals, morphological abnormalities of larvae and eggs, mutagenic, behavioral, and morphological alterations, contamination by polycyclic aromatic hydrocarbons, and mortality were detected. A decrease in species richness and abundance of oil-sensitive animals, an increase in opportunistic and oil-tolerant organisms, and simplification of communities was observed. The impacts were observed in sponges, corals, mollusks, crustaceans, polychaetes, echinoderms, turtles, birds, fish, and mammals. The majority of studies were conducted on bioindicator substrate-associated organisms, with 68.4% of the studies examining the benthos, 21.2% the nekton, and 10.4% the plankton. Moreover, most of the current short-term impacts assessment studies were focused on the species level (66.7%), with fewer studies on the community level (19%), and even fewer on oil-affected ecosystems (14.3%). Oil-related impacts were detected in five sensitive habitats, including blue-carbon ecosystems (e.g., mangroves and seagrass beds) and coastal reefs. These results call for the development of new ocean-basin observation systems for orphan spills. Finally, we discuss how these mysterious oil spills from unknown sources pose a risk to sustainable development goals and ocean-based actions to tackle global climate change.

Weathering impacts on petroleum biomarker, aromatic, and polar compounds in the spilled oil at the northeast coast of Brazil over time

After the wide oil spill reached the northeast of Brazil, the resurgence of oil was recorded and to evaluate this oil in detail, two samples collected in the state of Pernambuco in 2019 and 2021 were submitted to multiple analytical techniques. For both, we have found similar saturated biomarkers and triaromatic steroid ratios, implying that they are from the same spilled source. The n-alkanes, isoprenoids, and cycloalkanes were almost completely degraded due to evaporation, photooxidation, and/or biodegradation processes. The preferential loss of less alkylated PAHs than the more alkylated ones suggests that biodegradation was the most active process. This hypothesis is reinforced by the formation of mono and dicarboxylic acids assessed by GC × GC-TOFMS and ESI(-) FT-ICR MS high-resolution techniques. Furthermore, based on the ESI(-) FT-ICR MS results, three new ratios were proposed to evaluate the progress of the biodegradation process over time: O_x>2/O, SO_x/SO, and SO_x/N.

Ecological disturbances and abundance of anthropogenic pollutants in the aquatic ecosystem: Critical review of impact assessment on the aquatic animals

Anthropogenic toxins are discharged into the environment and distributed through a variety of environmental matrices. Trace contaminant detection and analysis has advanced dramatically in recent decades, necessitating further specialized technique development. These pollutants can be mobile and persistent in small amounts in the environment, and ecological receptors will interact with it. Despite the fact that few researches have been undertaken on invertebrate exposure, accumulation, and biological implications, it is apparent that a wide range of pollutants can accumulate in the tissues of aquatic insects, earthworms, amphipod crustaceans, and mollusks. Due to long-term stability during long-distance transit, a number of chemical and microbiological agents that were not previously deemed pollutants have been found in various environmental compartments. The uptake of such pollutants by the aquatic organism is done through the process of bioaccumulation when dangerous compounds accumulate in living beings while biomagnification is the process of a pollutant becoming more hazardous as it moves up the trophic chain. Organic and metal pollution harms animals of every species studied so far, from bacteria to phyla in between. The environmental protection agency says these poisons harm humans as well as a variety of aquatic organisms when the water quality is sacrificed in typical wastewater treatment systems. Contrary to popular belief, treated effluents discharged into aquatic bodies contain considerable levels of Anthropogenic contaminants. This evolution necessitates a more robust and recent advancement in the field of remediation and their techniques to completely discharge the various organic and inorganic contaminants.

Is there a similarity between the 2019 and 2022 oil spills that occurred on the coast of Ceará (Northeast Brazil)? An analysis based on forensic environmental geochemistry

The main objective of this study was to investigate the 2019 and 2022 oil spill events that occurred off the coast of the State of Ceará, Northeastern Brazil. To further assess these mysterious oil spills, we investigated whether the oils stranded on the beaches of Ceará in 2019 and 2022 had the same origin, whether their compositional differences were due to weathering processes, and whether the materials from both were natural or industrially processed. We collected oil samples in October 2019 and January 2022, soon after their appearance on the beaches. We applied a forensic environmental geochemistry approach using both one-dimensional and two-dimensional gas chromatography to assess chemical composition. The collected material had characteristics of crude oil and not refined oils. In addition, the 2022 oil samples collected over 130 km of the east coast of Ceará had a similar chemical profile and were thus considered to originate from the same source. However, these oils had distinct biomarker profiles compared to those of the 2019 oils, including resistant terpanes and triaromatic steranes, thus excluding the hypothesis that the oil that reached the coast of Ceará in January 2022 is related to the tragedy that occurred in 2019. From a geochemical perspective, the oil released in 2019 is more thermally mature than that released in 2022, with both having source rocks with distinct types of organic matter and depositional environments. As the coast of Ceará has vast ecological diversity and Marine Protected Areas, the possibility of occasional oil spills in the area causing severe environmental pollution should be investigated from multiple perspectives, including forensic environmental geochemistry.

Sandy beach macroinfauna response to the worst oil spill in Brazilian coast: No evidence of an acute impact

This study provides the first assessment of the impact of the worst oil spill ever faced by Brazilian sandy beaches by analyzing changes in the community structure of intertidal macroinfauna. Four sandy beaches were sampled three times after the oil spill, and the results were compared with previous data. The first sampling, conducted 15 days after the oil spill (October 2019), showed higher abundance of macroinfauna, which decreased in subsequent sampling conducted 60 and 120 days later, but never reached a lower level than in previous sampling. Of the macroinfauna species, Scolelepis sp. was most abundant in October 2019, while Donax gemmula was predominant during the other time periods. Changes observed in macroinfauna were due to natural fluctuations rather than a response to this disturbance. Characteristics of both the oil spill and macroinfauna contributed to the lack of acute impacts.