Brazilian Coast Research Articles

Extreme rain event highlights the lack of governance to face climate change in the Southeastern coast of Brazil

New rainfall records were registered in the southeastern region of Brazil during February 2023. The amount of rain in the north coast region of the State of São Paulo was more than 650 mm in less than two days. Landslides and tragedies with a socioeconomically vulnerable population marked this climatic extreme. The country has a regulatory system that suggests the elaboration and implementation of municipal public policies aimed at territorial organization, environmental conservation, and the prevention of disasters induced by natural hazards. In addition, both federal and state funds earmarked for such hazard's prevention have been underutilized over the last decade. In addition to this current devastating climate episode, other events were registered in this decade, reinforcing that financial governance is a key challenge to face the climate crisis in Brazil. The predicted future extreme events in different regions of Brazil will require a different governance system to minimize social inequality, seek sustainable alternatives for urban environments and manage to adapt cities for the challenges posed by climate change.

Hidden treasures of Camamu Bay, Bahia, Brazil: New records and two new species of Raspailiidae (Porifera, Demospongiae).

Currently one species of Cyamon Gray, 1867 and one species of Thrinacophora Ridley, 1885 are reported from the Brazilian coast: Cyamon agnani (Boury- Esnault, 1973) and Thrinacophora funiformis (Ridley & Dendy, 1886) respectively. We describe two new sponge species from Camamu Bay, Bahia, Brazil: Cyamon pedroalcoladoi sp. nov. and Thrinacophora melae sp. nov. . The specimens were found in shallow waters (23 m), on the sandy bottom with biodetritus. Cyamon perdroalcoladoi sp. nov. has unique spiculation consisting of two kinds of strongyles, five kinds of styles and two kinds of polyactine spicules. Thrinacophora melae sp. nov. is characterized by only one size of strongyles and raphides, and three kinds of styles. Also, the first record of Cyamon agnani from the state of Bahia726 km north of the type localityEsprito Santo, Brazil), a plate of spicule set from Western Atlantic species of Cyamon and the redefinition of both genera are included. Taxonomic keys, comparative tables of spicules and the geographic and bathymetric distributions from Western Atlantic Cyamon species and World Thrinacophora are presented.

A fast energized dispersive guided extraction of polycyclic aromatic hydrocarbons for risk-based seafood monitoring after an oil spill

After the 2019 oil spill disaster on the Brazilian coast, the demand for polycyclic aromatic hydrocarbons (PAH) analysis in seafood samples increased. The aim of this study was to develop an advanced method of energized dispersive guided extraction (EDGE) and quantification of PAH by liquid chromatography coupled to tandem mass spectrometry with atmospheric-pressure chemical ionization source (LC-APCI-MS/MS). The developed method was validated in terms of selectivity, working range (1.25 – 20.0 µg kg−1), matrix effect (relative errors > 20%, precision (CV < 30%), accuracy (77 – 128%), limits of detection (0.9 – 1.25 µg kg−1) and quantification (1.25 – 5.00 µg kg−1), and decision limit (2.9 – 7.8 µg kg−1). This method was applied to 238 samples to consolidate the first official Brazilian monitoring of PAH in seafood. PAH were quantified in 15% of samples, with concentrations up to 69.3 µg kg−1. The carcinogenic compound B[a]P was present in 4% of samples, with concentrations up to 42.7 µg kg−1. The health risk of seafood consumers was assessed using the margin of exposure (MOE) approach. Despite this, the risk assessment indicated that the disaster was of low concern to human health (MOE > 10.000). This new method increased laboratory throughput and was successfully applied to different types of samples, supporting monitoring of seafood after the disaster.

Comparing the effect of larval dispersal strategies on morphological versus genetic differentiation in two neotropical fiddler crabs

AbstractThe dispersal mode of estuarine invertebrates has a strong effect on genetic variability and phenotypic expression, potentially maintaining gene flow among widely separated populations or limiting connectivity among close ones. Understanding the dispersal strategies effects can support adequate strategies for environment management and understand the evolutionary history of the studied species. A comparative study on the effect of larval dispersal strategies (export vs retention) along the overall geographic distribution ranges of adult populations of two co‐distributed fiddler crab species was performed. Geometric morphometric techniques were used to evaluate morphological differentiation in the shape of the carapace and major cheliped propodus in 10 populations of Minuca mordax and five populations of Leptuca leptodactyla. Potential genetic differentiation was assessed using DNA sequence data from up to 170 fiddler crab specimens, corresponding to the mitochondrial gene cytochrome c oxidase subunit 1 (COX1). Patterns of genetic and morphological characteristics diverged among populations of both species. In terms of morphology, populations of both species showed intraspecific variation in the shape of the carapace and, to a lesser extent, in the major cheliped propodus. This observed intraspecific variation followed a clear geographic pattern of morphometric differentiation, in which the geographic origin is associated with a phenotypic response to the environmental diversity along the extended Brazilian coast. In contrast, there are shared haplotypes in populations separated by more than 4000 km, but with significant ΦST values among most populations of L. leptodactyla and M. mordax, suggesting a moderate to high level of gene flow. Therefore, it can be concluded that the split of the Central South Equatorial Current has not acted as an efficient long‐term barrier to the dispersal of larvae in both species. In M. mordax, a slight limitation of genetic exchange can be observed between the southernmost populations and the remaining ones. This first evidence of genetic structuring within this widely distributed species is consistent with its documented strategy to retain larvae in the estuarine environments. However, occasional transport of larvae to more open coastal waters seems to maintain stepwise gene flow between neighboring populations. Overall, our results still provide evidence of more pronounced genetic homogeneity in a species with a larval export strategy (L. leptodactyla) compared to a species with a larval retention strategy (M. mordax). This suggests that larval dispersal strategies, coupled with the microhabitat in which the respective species occur, have a noticeable effect on the degree of gene flow. Most likely, these biological aspects are further influenced by the estuarine and coastline geomorphology.

Geochemical and sedimentary features of the unusual association between hybrid carbonates and beachrocks in the Southeastern Brazilian Coast

Rocks formed in beach environments during the Holocene constitute strong evidences of relative sea level variations (RSL) and supply important data for paleoenvironmental reconstruction. At the southeastern Brazilian coast, an unusual association of lithofacies composed of hybrid carbonates and beachrocks was identified on the Parati beach in the Espírito Santo state. In this study, radiocarbon dating and sedimentary and geochemical characterization of five lithofacies were conducted, with the aim of reconstructing the paleoenvironmental conditions of deposition and cementation of this facies association. The lithofacies were classified as quartzarenites, bioclastic quartzarenites, hybrid carbonate and hybrid boundstones, with ages ranging from 2600 to 700 cal yr BP. Sedimentary and geochemical changes observed in these five lithofacies of the shallow shelf off southeastern Brazil reinforce evidence relative sea level variations during the Holocene.

Four new species of dragonfish genus Eustomias (Stomiiformes: Stomiidae: Melanostomiinae) from the western tropical Atlantic, with remarks on Eustomias minimus Clarke, 1999

Abstract Four new species of the scaleless black dragonfish genus Eustomias are described based on specimens collected during the ABRACOS (Acoustics along the BRAzilian COaSt) expeditions along the Fernando de Noronha Ridge, off northeastern Brazil, western tropical Atlantic. Eustomias (Haploclonus) antea sp. nov. differs from its congeners by having a long chin barbel without appendages, ending in a very small terminal bulb without terminal filaments. Eustomias (Haploclonus) lucenae sp. nov. has the lowest count of photophores in the lateral series (56) and a simple, short barbel, ending in a small and asymmetrical terminal bulb. Eustomias (Nominostomias) ophioglossa sp. nov. differs from its congeners by the long chin barbel with two terminal bulbs and long terminal filament with bifurcated axis along its length and with bulblets of different sizes and arrangements inside. Eustomias (Nominostomias) bertrandi sp. nov. can be distinguished by the long chin barbel with two terminal bulbs, the distal bulb more than twice as long as the proximal one, and a short terminal filament. Morphological description of a specimen identified as Eustomias (Dinematochirus) cf. minimus is provided, and an overview of the species of Eustomias reported in Brazilian waters is presented and discussed.

Late holocene progradation in a mixed siliciclastic-carbonate beach ridges system, Northeast Brazil

A morpho-sedimentary analysis based on grain size, texture, composition, luminescence ages, and morphologic pattern was performed in a beach ridge system located on the Brazilian semiarid coast to understand the siliciclastic and bioclastic mixtures during a progradation of strandplain. Moreover, the rhodolith beds were adopted as a new sea-level proxy to analyze the coastline displacement trajectory of the mixed siliciclastic-carbonate sedimentary environment. The beach ridges system shows a succession of ridges and swales interrupted in the central part by a lagoon plain, the western sector exhibits the crest relief related to the ancient foredune on top and underlying foreshore deposits, and the eastern sector shows a great presence of transgressive dunes overlying beach ridges. Foredune/aeolian facies and the foreshore facies (with rhodolith beds associated) show siliciclastic and bioclastic mixture related to the late Holocene coastal progradation with a progressive increase in carbonate influence, mainly calcareous algae, foraminifera, and molluscs. Moreover, comparing the modern counterpart of the older beach ridges, finer and better-sorted sediments were found in the ancient deposits than in the modern ones. Thus, the progradation was marked by an eminently dissipative beach system. This coeval sedimentation is controlled by key local settings, such as the semi-arid climate, the absence of local fluvial input, the shallow shelf, and the carbonate factory for bioclastic supply. The presence of rhodolith beds in the foreshore facies with an elevation lowering trend towards the modern coastline reinforces the hypothesis that the mixed progradational pattern was accompanied by a small fall in sea level, which corroborates with late Holocene regional curves and provides pioneering preliminary contributions for the studied area.

Taxonomía del género Arachis (Leguminosae)

Taxonomía del género Arachis (Leguminosae)

Traditional and local communities as key actors to identify climate-related disaster impacts: a citizen science approach in Southeast Brazilian coastal areas

The impacts of climate-related disasters can be estimated by climate models. However, climate models are frequently downscaled to specific settings to facilitate Disaster Risk Management (DRM) to better understand local impacts and avoid overlooking uncertainties. Several studies have registered the increasing importance of recognizing traditional knowledge, co-design, and collaboration with local communities in developing DRM strategies. The objective of this research was co-design local-scale observations with traditional and local communities to characterize their local context regarding the impacts of climate-related disasters. The citizen science approach coupled with participatory action research was conducted with two traditional communities in the Southeast of the Brazilian coast: Quilombo do Campinho da Independência in Paraty, Rio de Janeiro, and the Caiçara (artisanal fishing) community of Ubatumirim in Ubatuba, São Paulo. Working groups were organized with leaders to become community researchers, conducting interviews and actively mobilizing their communities. A structured questionnaire was developed, adapting 22 variables taken from the Protocol for the Collection of Cross-Cultural Comparative Data on Local Indicators of Climate Change Impacts—LICCI Protocol. A total of 366 impacts were analyzed, after combining the georeferencing form data collected—Survey123 (280 impacts) and the interviews with community leaders (86 impacts). The results showed a significant level of cohesion (α = 0.01) between the Caiçara (artisanal fishers) and Quilombola (Afro-descendants) perceptions of climate-related events associated with their subsistence practices and climate variability. These findings highlighting the importance of DRM proposals that recognize traditional peoples and local communities as frontline vulnerable populations while acknowledging their role as key actors in identifying impacts, collecting data on land use and territory, subsistence-oriented activities, and cosmovision. However, it is still necessary to address climate change challenges at different scales. To do this, it is crucial to promote cognitive justice though the recognition of the values of the memories, perceptions and local knowledge, by scaling up locally-driven observations that empower local communities to lead their own climate adaptation efforts.

Association between PAH and plastic fragments on Brazilian coast beaches: a baseline assessment.

Plastic materials have many destinies on the environment, and one of them is its continuous fragmentation, originating microplastics (MP). MP act as an adsorption surface for organic pollutants like polycyclic aromatic hydrocarbons (PAH). Due to its toxic and harmful properties, 16 PAH are defined as priorities in studies. Several works have evaluated the occurrence of MP and PAH individually in environmental matrices, but just a few have investigated their association. The present study aims to investigate PAH occurrence, sources, and concentration in MP from beach sediments of eight Brazilian coastal states. Sixteen PAH were analyzed by gas chromatography, in which 14 PAH were detected, and PAH total concentration (ΣPAH) ranged from 0.25 to 71.60ngg-1. In the North and Northeast regions, the low PAH concentrations in MP appear to be related to the intense hydrodynamic processes. Naphthalene levels on the Styrofoam were above the threshold effect level in two samples and near it on one; therefore, effects in the organisms might occur due to these PAH. The Southeast and South regions are the only ones with previous studies relating PAH with MP, and ΣPAH ranged from 0.34 to 2.52ngg-1. According to the diagnostic ratios, the PAH sources were associated with industrial and port activities, untreated effluent disposal, and urban runoff by pluvial waters. The highest ΣPAH level was found in the Styrofoam samples, suggesting that this MP type might contribute considerable to PAH dispersion on Brazilian coast beaches.

DNA barcode reveals occurrence of threatened species and hidden diversity on Teleost fish trade in the Coastal Amazon

This study aimed to identify the teleost fish species sold in Bragança, a major fishing hub on the north coast of Brazil. The COI gene analysis was performed for the identification of fish species. The local market uses common names that are not accurate and do not reflect the diversity of the species. 204 sequences were obtained, with 119 haplotypes. 83 species were identified by comparing with public databases and constructing phylogenetic trees, with Carangidae being the most prevalent family. The study also found Haemulon atlanticus, Menticirrhus cuiaranensis and Hoplias misioneira, a newly described species from the Amazon basin, among the samples. Additionally, 73 commercial names were recorded, including 10 categories, and the illegal trade of Epinephelus itajara was detected. The DNA Barcode method proved to be effective for discriminating the species. The study highlights that common and commercial names are vague and underestimate the fish diversity, and that Brazil needs to revise its regulations for commercial and scientific names.

First record of Sooty Tern, Onychoprion fuscatus (Linnaeus, 1766) (Laridae, Charadriiformes), from S&amp;atilde;o Paulo state, Brazil

Sooty Tern, Onychoprion fuscatus (Linnaeus 1766), is a rare species along the Brazilian coast due to oceanic habits. We report the first documented record of this species from S&amp;atilde;o Paulo state, southeastern Brazil. The specimen was found beached in Mongagu&amp;aacute; municipality. Morphological assessment, necropsy, and histological analysis allowed us to identify species, reproductive state (non-breeding), and sex (male) of this specimen.

#DeOlhoNosCorais: a polygonal annotated dataset to optimize coral monitoring.

Corals are colonial animals within the Phylum Cnidaria that form coral reefs, playing a significant role in marine environments by providing habitat for fish, mollusks, crustaceans, sponges, algae, and other organisms. Global climate changes are causing more intense and frequent thermal stress events, leading to corals losing their color due to the disruption of a symbiotic relationship with photosynthetic endosymbionts. Given the importance of corals to the marine environment, monitoring coral reefs is critical to understanding their response to anthropogenic impacts. Most coral monitoring activities involve underwater photographs, which can be costly to generate on large spatial scales and require processing and analysis that may be time-consuming. The Marine Ecology Laboratory (LECOM) at the Federal University of Rio Grande do Norte (UFRN) developed the project "#DeOlhoNosCorais" which encourages users to post photos of coral reefs on their social media (Instagram) using this hashtag, enabling people without previous scientific training to contribute to coral monitoring. The laboratory team identifies the species and gathers information on coral health along the Brazilian coast by analyzing each picture posted on social media. To optimize this process, we conducted baseline experiments for image classification and semantic segmentation. We analyzed the classification results of three different machine learning models using the Local Interpretable Model-agnostic Explanations (LIME) algorithm. The best results were achieved by combining EfficientNet for feature extraction and Logistic Regression for classification. Regarding semantic segmentation, the U-Net Pix2Pix model produced a pixel-level accuracy of 86%. Our results indicate that this tool can enhance image selection for coral monitoring purposes and open several perspectives for improving classification performance. Furthermore, our findings can be expanded by incorporating other datasets to create a tool that streamlines the time and cost associated with analyzing coral reef images across various regions.

Reliability-based fatigue inspection planning for mooring chains of floating systems

The safety of offshore floating units, supporting renewable energy generation or oil and gas production facilities, highly depends on the platform's station keeping capability, which is provided by mooring systems. Lately, there has been a high rate of mooring line failures, leading to increased interest in improving their design and maintenance methodologies. Specifically, upper chain segments at the splash zone are more prone to suffer from the effects of corrosion degradation and fatigue. The fatigue limit state and the corrosion allowance of mooring chains are safety requirements that need to be verified continuously through mandatory regular inspections. Current trends related to mooring chains point to the development of new methodologies for fatigue damage calculation, corrosion degradation models and inspection planning methods. The present work proposes a practical reliability-based method for planning future inspections of such mooring line components, which combines recently-developed fatigue and corrosion methodologies and takes into account the results of the previous inspections. The risk-based assessment of the mooring system is continuously updated with new inspection data, and is a suitable tool for monitoring the current reliability level of the structure. This work presents a case study of a FPSO on the Brazilian coast as a practical example of the application of the proposed inspection planning method. In this way, it aims to help future designers and operators to avoid failures in mooring chains and to optimizing inspection and maintenance costs.

First report of deep-sea litter on the Brazilian continental slope, Southwestern Atlantic

The presence of marine litter in the deep ocean (>200 m depth) may represent an invisible threat that has been neglected due to the scarcity of data. Herein, we provide the first report of persistent marine litter on the Southwestern Atlantic continental slope. Marine litter was collected onboard the Brazilian R/V Alpha Crucis, using bottom trawling, in 28 out of 31 sampled stations, between 274 and 1520 m depth, in two distinct areas off the southern Brazilian coast. In total, 603 items and 13.8 kg of litter were collected and classified according to the type of material. Plastic was the most frequent and most abundant material found. Although there was no bathymetric variation along the slope, density of litter was considerably higher off São Paulo than off Santa Catarina State, supposedly due to the heavier presence of oil and gas platforms and large cargo vessels.

Integrating morphological, molecular and cytogenetic data for F2 sea turtle hybrids diagnosis revealed balanced chromosomal sets.

Hybridization could be considered part of the evolutionary history of many species. The hybridization among sea turtle species on the Brazilian coast is atypical and occurs where nesting areas and reproductive seasons overlap. Integrated analysis of morphology and genetics is still scarce, and there is no evidence of the parental chromosome set distribution in sea turtle interspecific hybrids. In this study, chromosome markers previously established for pure sea turtle species were combined with morphological and molecular analyses aiming to recognize genetic composition and chromosome sets in possible interspecific hybrids initially identified by mixed morphology. The data showed that one hybrid could be an F2 individual among Caretta caretta × Eretmochelys imbricata × Chelonia mydas, and another is resulting from backcross between C. caretta × Lepidochelys olivacea. Native alleles of different parental lineages were reported in the hybrids, and, despite this, it was verified that the hybrid chromosome sets were still balanced. Thus, how sea turtle hybridism can affect genetic features in the long term is a concern, as the implications of the crossing-over in hybrid chromosomal sets and the effects on genetic function are still unpredictable.

Methodology for the estimation of an oil spill origin: Analysis of the 2019 Brazilian coast oil spill

This research presents a procedure for determining the origin of marine pollution through the use of a time-direct trajectory modeling, associated with a Kriging metamodel technique and Monte Carlo random sampling. These methods were applied to a real case, specifically the oil spill that affected the Brazilian coast in the second half of 2019 and early 2020. A total of 140 trajectories, defined by the geographical coordinates of the origin and the spill date, were generated through Latin Hypercube Sampling and simulated using the PyGNOME model to construct the Kriging metamodel. The metamodel demonstrated cost-effectiveness by efficiently simulating numerous input data combinations which were compared and optimized based on available real data regarding temporal and spatial pollution distribution.

Integrative species delimitation uncovers hidden diversity within the Pithecopus hypochondrialis species complex (Hylidae, Phyllomedusinae) and its phylogeography reveals Plio-Pleistocene connectivity among Neotropical savannas

Despite their limited vagility and pronounced habitat heterogeneity in the tropics, many anuran species have unexpectedly extensive geographic ranges. One prominent example of this phenomenon is Pithecopus hypochondrialis, which is found in the Cerrado, Guianan savanna, and Llanos domains, as well as isolated tracts of savanna and open habitat within the Amazon Forest. The present study employs an integrative species delimitation approach to test the hypothesis that P. hypochondrialis is in fact a species complex. We also reconstruct the relationships among the lineages delimited here and other Pithecopus species. In this study, we employ Ecological Niche Modelling (ENM) and spatiotemporal phylogeographic reconstruction approaches to evaluate a multitude of scenarios of connectivity across the Neotropical savannas. We identified three divergent lineages, two of which have been described previously. The lineages were allocated to a lowland Pithecopus clade, although the relationships among these lineages are weakly supported. Both the ENM and the phylogeographic reconstruction highlight the occurrence of periods of connectivity among the Neotropical savannas over the course of the Pliocene and Pleistocene epochs. These processes extended from eastern Amazonia to the northern coast of Brazil. The findings of the present study highlight the presence of hidden diversity within P. hypochondrialis, and reinforce the need for a comprehensive taxonomic review. These findings also indicate intricate and highly dynamic patterns of connectivity across the Neotropical savannas that date back to the Pliocene.

Trypauchen vagina (Bloch &amp; Schneider, 1801) a new established species in the Southwestern Atlantic

AbstractTrypauchen vagina (Bloch &amp; Schneider, 1801) is a goby that lives burrowed into the substrata feeding on small invertebrates. It is native to the Indo‐pacific region, ranging from Kuwait to China. Recently, this fish has been reported outside the original range of distribution, being found in the Mediterranean Sea, and more recently in the northeastern Brazilian coast. The Mediterranean reports are usually associated with Lessepsian migration, while the reports from Brazil are possibly related to ballast water transportation. In the present work, we provide eight new records from southeastern Brazilian coast, all made in São Paulo state, far from the first record. These additional records raised concern since the presence of an alien species could implicate in environmental and economic losses. Thus, we decide to model the environmental suitability for this goby in the Brazilian coast, specially focusing on major ports, usually places with high ballast water propagule pressure. In addition, an analysis of the suitability in the Red Sea was also made, to verify the hypothesis of Lessepsian migration. The results revealed that temperature and primary productivity are among the most important parameters for the presence of T. vagina, also indicating a high environmental suitability for this species in the Red Sea and Brazilian coast, especially in southeastern region, where the new records were made. Due to the number of collected individuals, it is hard to affirm that this taxon presents a self‐sustaining population in Brazilian waters, but the several registers, in different locations and different life stages point to an establishment of the species in this new region. This population status allied with a high environmental suitability is alarming and should motivate new studies concerning T. vagina in Brazilian waters.

Patterns of hyperostosis during the ontogenic development of Atlantic spadefish (Broussonet, 1782) in Brazilian coast.

Marine teleost species of commercial interest are often reported with hyperostosis, an osteological condition that results in bone thickening. Various specimens of Atlantic Spadefish Chaetodipterus faber (n = 86) obtained from artisanal fishermen in Rio de Janeiro, Brazil, were radiographed and assessed to detect the occurrence of hyperostosis across four different size classes. Of the examined individuals, 58.62% displayed signs of hyperostosis, which manifested in eight skeletal regions, notably in the supraoccipital crest, cleithrum and supraneural areas. In the vertebral column, hyperostosis was more frequently observed in haemal spines than in neural spines, predominantly between the sixth and eighth caudal vertebrae. The smallest size class (<200 mm total length) showed a low frequency of hyperostosis at 7.89%. This frequency escalated for larger classes, reaching 94.12% in individuals measuring 200-300 mm in total length and was observed in all individuals exceeding 300 mm. Hyperostosis exhibited an ontogenetic development pattern, where both the occurrence frequencies and the sizes of the affected bones expanded in proportion to the fish size. This is the first description of the hyperostosis pattern of development for the species, an important commercial resource.