An extensive reef system at the Amazon River mouth

Impact of iron exposure on Brazilian coral reefs: Acute vs. chronic stress responses

Prior research has shown that exposure to metals increases corals vulnerability to bleaching by heightened oxidative stress. Understanding the impact of metal contamination on coral health in their natural environmental is crucial. This study investigate the effects of iron (Fe) exposure on Brazilian coral reef species. We evaluated the response of Mussismilia harttii, Millepora alcicornis, and Siderastrea sp. to acute (4 days) and chronic (28 days) Fe exposure under environmentally relevant concentrations (0, 100, 300 and 900 μg L-1). Experiments were conducted in laboratory and in a marine mesocosm Biomarkers including Fe bioaccumulation, lipid peroxidation (LPO), protein carbonylation (PCN), and DNA damage were measured. The correlation between chronic exposure results and environmental factors were also analyzed. The hypotheses were: a) Fe exposure would increase ROS production in corals, leading to biomolecule damage; b) acute and chronic Fe exposure would affect ROS production and biomolecule damage differently; c) Fe bioaccumulation would vary between species and concentrations; and d) environmental factors might influence coral responses to Fe. Results indicated that all species exhibited increased Fe bioaccumulation as metal concentrations increased, suggesting a common ability to absorb and accumulate Fe. The oxidative damage response vired between acute and chronic exposure, with acute exposure causing more damage while chronic exposure showed a temporal reduction in damage. Environmental factors (e.g. temperature, pH, salinity and dissolved oxygen) also influenced the coral responses, either exacerbating or mitigating oxidative stress effects. These findings highlight the importance of understanding Fe contamination impacts for the conservation of Brazilian coral reefs.

Lepas anatifera as a biomonitor of ocean health, ecological impacts, and cancer risk in a new frontier of exploration (Brazilian Equatorial Margin)

For the first time, a comprehensive evaluation was carried out to assess the presence of banned, restricted, and widely used permitted pesticides in Lepas anatifera, a globally distributed oceanic species. This study aims to shed light on ocean health along Brazil's equatorial margin, a region identified as a priority for future exploration. Additionally, it seeks to contribute to the understanding of the South Atlantic Ocean, a region with limited scientific studies, by evaluating the potential risks associated with the ingestion of these barnacles. Specifically, the study investigates their potential role in cancer development or disruptions to the endocrine system, considering their critical position within the oceanic food web. A total of 60 organic pollutant compounds were analyzed in 1903 individuals distributed in 19 sample groups of L. anatifera using gas chromatography (GC) equipped with both an electron capture detector (ECD) and a nitrogen-phosphorus detector (NPD) (GC-ECD/NPD). The highest total concentration of permitted pesticides in L. anatifera was triazines (ƩTPs = 2314.87 ng/g), followed by organophosphorus (ƩOPPs = 231.86 ng/g) and pyrethroids (ƩPPs = 32.45 ng/g). Among banned and restricted substances, organochlorine pesticides (ƩOCPs = 24.30 ng/g) had the highest concentrations, followed by polybrominated diphenyl ethers (ƩPBDEs = 10.23 ng/g) and polychlorinated biphenyls (ƩPCBs = 6.01 ng/g). The cancer risk from polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) was considered insignificant or acceptable. L. anatifera is highlighted as an excellent oceanic biomonitor, demonstrating the ability to accumulate various traditional and emerging organic contaminants, necessitating improved waste management policies and monitoring plans. While PCBs and OCPs are well-known for causing severe diseases such as cancer, all the substances analyzed in this study have the potential to disrupt the endocrine and immune systems and impair reproductive functions. Some may even lead to feminization in animals, among other adverse health effects. These findings highlight the urgent need for effective policies and actions to improve the management of solid and liquid waste, alongside comprehensive plans to monitor the environmental fate of these substances and assess their true risks to living organisms.

Calcium carbonate production by the massive coral Mussismilia hispida in subtropical reefs of the Southwestern Atlantic

Corals, as primary calcifiers, play a vital role in synthesizing calcium carbonate (CaCO3) to build their skeletons, contributing to the formation of complex benthic habitats that support high biodiversity and marine productivity. However, coral habitats have dramatically declined worldwide due to ocean warming and acidification. Interestingly, the subtropical Southwestern Atlantic (SWA) has emerged as a potential refuge, where corals like Mussismilia hispida exhibit resilience to thermal anomalies. In this study, we estimate CaCO3 production by M. hispida in subtropical SWA reefs, revealing an average growth rate of 4.3 ± 1 mm/year and a CaCO3 production rate of 1.31 ± 0.3 kg. m-2. year-1. These values are comparable to tropical reef systems, suggesting that M. hispida contributes significantly to carbonate production, even in higher latitude environments. Moreover, despite experiencing one of the most intense thermal anomalies recorded, colony abundance (i.e., ind. m-2) and carbonate production remained stable, emphasizing the potential of the region as a climate refuge. While many tropical reefs act as net CO2 sources due to the release of CO2 during calcification, SWA subtropical reefs present lower coverage of corals. They are dominated by algae and other primary producers, acting as an important potential carbon sink through photosynthesis and long-term storage of carbon over centuries as mineralized CaCO3. Thus, we provide evidence that M. hispida, by producing ∼170 tons. year-1 of CaCO3 in the subtropical reefs of the Alcatrazes Archipelago, acts as a key player in carbon sequestration and CaCO3 production in higher latitude SWA areas.

Charting the invasion: Predicting Tubastraea spp. next move into Brazilian marine protected areas

In the late 1980s, the sun coral, Tubastraea spp. (Scleractinia; Dendrophylliidae), was introduced to Brazil via biofouling on oil platforms and drilling vessels. Today, these corals have spread over 3000 km of the Brazilian coast, colonizing a range of habitats, including oil platforms, drilling ships, monobuoys and natural reefs. Concerned about the potential impacts on Brazilian marine ecosystems, management actions have been implemented in various regions. To achieve success in management, early detection and monitoring are essential. To address this need, our study focuses on modeling the habitat suitability for Tubastraea spp. along the Brazilian coast, aiming to support control and monitoring activities within marine protected areas (MPAs). By utilizing habitat suitability models that incorporate both environmental and anthropogenic predictors, our results indicate a broad potential distribution for Tubastraea spp., with oil and gas extraction identified as the primary influencing factor. Our analysis ranked the most vulnerable Brazilian MPAs to Tubastraea spp. invasion, highlighting the Arapiranga-Tromaí Extractive Reserve, Trindade and Martim Vaz Islands Natural Monument, and the Costa dos Corais Environmental Protected Area as the most threatened. This study offers valuable insights into prioritizing efforts and resources for the control, monitoring, and prevention of sun coral invasion along the Brazilian coast, particularly in light of ongoing discussions about the oil industry's plans to operate at the Amazon River mouth.

The Thermal Stress History of South Atlantic Reefs Reveals Increasing Intensity, Duration, Frequency, and Likely Undocumented Bleaching Episodes

The primary consequence of global warming for reefs is coral bleaching, often leading to extensive coral mortality. Although bleaching is well-documented globally, the thermal stress and bleaching experienced by the unique South Atlantic reefs remain largely unknown due to insufficient monitoring on both spatial and temporal scales. Therefore, this work aimed to reconstruct past thermal stress episodes across South Atlantic reefs, and assessed whether episodes are becoming more intense, longer-lasting, and more frequent. We retrieved daily 5 km-resolution Degree Heating Week (DHW) data from the U.S. National Oceanic and Atmospheric Administration Coral Reef Watch server for 33 reef sites spanning the last 40 years. For each thermal stress episode, we assessed the intensity (maximum DHW value), duration (number of continuous days under stress), and frequency (number of days between episodes). Generalized linear models were fitted to intensity, duration, and frequency data to evaluate the influence of latitude and the time x region interaction as predictors. We recorded multiple thermal stress episodes, increasing from 2010 onwards, ranging from 10 episodes between 1985-89 and 75 between 2020-24. Intensity and duration increased over time across the entire South Atlantic. Frequency also increased across the Southwestern Atlantic coast and oceanic islands, but not for Africa. Episodes at higher latitudes were more intense, prolonged, and frequent. The validity of the thermal stress history reconstruction was groundtruthed using information from the Abrolhos Bank, the only consistently monitored reef site in the South Atlantic-DHW data accurately matched the observed bleaching episodes at this site. With this, our dataset shows that multiple bleaching episodes likely occurred in the South Atlantic, but went undocumented in the field. Therefore, the information currently available for the South Atlantic likely underestimates the extent of bleaching occurring in the area, which is experiencing increases in intensity, duration, and frequency of thermal stress.

Bacterial and Symbiodiniaceae communities' variation in corals with distinct traits and geographical distribution

Coral microbiomes play crucial roles in holobiont homeostasis and adaptation. The host's ability to populate broad ecological niches and to cope with environmental changes seems to be related to the flexibility of the coral microbiome. By means of high-throughput DNA sequencing we characterized simultaneously both bacterial (16S rRNA) and Symbiodiniaceae (ITS2) communities of four reef-building coral species (Mussismilia braziliensis, Mussismilia harttii, Montastraea cavernosa, and Favia gravida) that differ in geographic distribution and niche specificity. Samples were collected in a marginal reef system (Abrolhos, Brazil) in four sites of contrasting irradiance and turbidity. Biological filters governed by the host are important in shaping corals' microbiome structure. More structured associated microbial communities by reef site tend to occur in coral species with broader geographic and depth ranges, especially for Symbiodiniaceae, whereas the endemic and habitat-specialist host, M. braziliensis, has relatively more homogenous bacterial communities with more exclusive members. Our findings lend credence to the hypothesis that higher microbiome flexibility renders corals more adaptable to diverse environments, a trend that should be investigated in more hosts and reef areas.

First records of Glyphus marsupialis Filhol, 1884 (Decapoda: Pasiphaeidae) in southwestern Atlantic deep waters and extensions of the known distribution of two Pasiphaea species

The Pasiphaeidae Dana, 1852 are a marine shrimp family occurring in both shallow and deeper waters, with its greatest diversity occurring in tropical and subtropical deep seas. This family includes seven genera and 104 species, and is globally distributed. Currently, the genus Pasiphaea Savigny, 1816 includes 73 species, seven of them recorded in the southwestern Atlantic. The genus Glyphus Filhol, 1884 is monotypic and is known from the Indo-Pacific region, the East Pacific Ocean and in the Eastern Atlantic. Herein, we report the first record of the genus in the southwestern Atlantic, completing a cosmopolitan distributional pattern. Further, two new records of Pasiphaea species are commented upon (P. major Hayashi, 2006; P. tarda Kroyer, 1845) along the Northern coastline of the Brazilian coast (Amapá state), also reporting a new host interaction between Thalassomyces sp. and P. major. This is the first record of this Ellobiopsidae genus in the South Atlantic Ocean. The material herein analyzed was sampled by the ReviZEE Program/North, in 1996/2001, during deep-water trawls in the Amazonian slope (Amapá state), at depths from 250 to 1100 m. All material is deposited in the Coleção Carcinológica do Laboratório de Crustáceos (Labcrus)/Universidade Federal Rural da Amazônia (UFRA). The global distribution of Glyphus is commonly observed in deep species and although it has been occasionally contested by the discovery of species complexes (using very detailed morphological and molecular data analyses) with the currently available information, the present material is clearly identifiable as G. marsupialis.

Assessment of cancer and dietary risks in commercially valuable marine organisms in coast of a region of future exploration (Equatorial South Atlantic)

The Equatorial South Atlantic region, spanning over 1700 km, is currently undergoing extensive exploitation through various activities such as oil extraction, desalination plants, marine mineral explorations, and wind power for green hydrogen production. This undoubtedly also contributes to the exacerbation of pre-existing chronic environmental impacts. This study aims to investigate the concentrations of 60 substances, categorized as Persistent Organic Pollutants (POPs) and Contaminants of Emerging Concern (CECs) from various classes including: polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), as well as Pyrethroids (PPs), Triazines (TPs) and Organophosphates (OPPs) pesticides in consumable fish, shellfish, and crabs. The bivalve (Mytella charruana), crab (Ucides cordatus), and catfish (Sciades herzbergii) samples were collected in areas of ecological, environmental and economic importance. This data was used to estimate concentrations in the organisms, and to calculate cancer and human health risk. The most prevalent pollutant classes in the organisms were OCPs, followed by TPs and PPs. Shellfish and fish samples had more compounds indicating health risks, when compared to crabs. The substances causing cancer risks varied across organisms and study areas. The heightened cancer risks linked to specific compounds in various species highlight the urgent need to address persistent pollutants to prevent long-term health impacts on both humans and wildlife. Compounds such as PPs, TPs, and OPPs pose significant risks of neurotoxicity and endocrine disruption. This study underscores the interconnectedness of environmental and human health in coastal ecosystems, calling for continuous monitoring and adaptive management strategies to protect these fragile environments and the communities that rely on them.

Exploring depth-related patterns of sponge diversity and abundance in marginal reefs

Marine sponges play a vital role in the reef's benthic community; however, understanding how their diversity and abundance vary with depth is a major challenge, especially on marginal reefs in areas deeper than 30 m. To help bridge this gap, we used underwater videos at 24 locations between 2- and 62-meter depths on a marginal reef system in the Southwestern Atlantic to investigate the effect of depth on the sponge metacommunity. Specifically, we quantified the abundance, density, and taxonomic composition of sponge communities, and decomposed their gamma (γ) diversity into alpha (α) and beta (β) components. We also assessed whether beta diversity was driven by species replacement (turnover) or by nesting of local communities (nestedness). We identified 2020 marine sponge individuals, which belong to 36 species and 24 genera. As expected, deep areas (i.e., those greater than 30 m) presented greater sponge abundance and more than eightfold the number of sponges per square meter compared to shallow areas. About 50% of the species that occurred in shallow areas (<30 m) also occurred in deep areas. Contrarily to expectations, alpha diversity of rare (0 D α), typical (1 D α), or dominant (2 D α) species did not vary with depth, but the shallow areas had greater beta diversity than the deep ones, especially for typical (1 D β) and dominant (2 D β) species. Between 92.7% and 95.7% of the beta diversity was given by species turnover both inside and between shallow and deep areas. Our results support previous studies that found greater sponge abundance and density in deep areas and reveal that species sorting is stronger at smaller depths, generating more beta diversity across local communities in shallow than deep areas. Because turnover is the major driver at any depth, the entire depth gradient should be considered in management and conservation strategies.

Morphology and molecular evidence reveal hidden diversity among snapping shrimp of the Alpheus obesomanus group (Decapoda: Alpheidae) with the description of a new species from Brazil

The snapping shrimp family Alpheidae Rafinesque, 1815 includes numerous species, most of which present controversial geographical distributions. The disjunct distribution of Alpheus simus Guérin-Méneville, 1856 in the western Atlantic, from Florida to the south of the Caribbean Sea and then from Rio Grande do Norte to Bahia in Brazil, suggests that Brazilian material may belong to an undescribed species. The examination of specimens previously identified as A. simus revealed the distinct morphology of material from Brazil, resulting in the description of a new species based on morphological and molecular evidence. The specimens were collected from fragments of fire coral at the Parque Municipal Marinho do Recife de Fora, Porto Seguro, Bahia, Brazil. Alpheus coralvivo sp. nov. belongs to the A. obesomanus group and is morphologically similar to A. simus (northwestern Atlantic) and A. saxidomus Holthuis, 1980 (eastern Pacific), differing mainly in the stylocerite and scaphocerite lengths and in the large gap between the cephalothorax and pleuron of the first pleonal segment. Molecular analysis using the mitochondrial cytochrome oxidase subunit I gene support the existence of the new species.

Hydroids from a reef system under the influence of the Amazon River plume, Brazil

The Amazon Reef System (ARS) is one of the most important shallow and mesophotic reef ecosystems in the South Atlantic Ocean. The ARS consists mainly of extensive beds of calcareous algae interspersed by assemblages of octocorals and sponges. The enormous freshwater discharge from the Amazon River forms a plume along the extensive Amazon continental shelf, for which the hydroid community is still largely unknown. The aim of this study is to document the diversity and distribution of hydroids from the ARS, as well as to infer the influence of the plume on species composition in the different zones. Samples were collected at ninety-six stations between 15 and 240 m deep on the Amazon shelf. A total of 37 species were recorded in the studied area. Hydroid assemblages are richer in zones under lower river plume influence, and species composition differs significantly between zones with and without plume influence (PERMANOVA, p = 0.0025). The dissolved oxygen and nitrate ranges were the environmental variables significantly correlated with the hydroid distribution. This study is the first surveying the hydroid species composition and richness in the ARS, highlighting the presence of a typical reef biota and that further faunal studies in underexplored areas of the Atlantic should reveal the distribution of many poorly known hydroids species.

Caribbean red snapper fishing performance indicators in Brazilian amazon shelf: Is it the beginning of the end of a fishing system?

Red snapper fishing (Lutjanus purpureus) is an important fishing activity for the Brazilian economy due to its export. The scarcity of up-to-date information on this system's ecology, economy, and social characteristics contributes to inefficient management. We analyze whether the commercial snapper fishery on the Amazon continental shelf is socioecologically sustainable. For this, an assessment tool was used that can be applied to fishing systems with little data, the Fisheries Performance Indicators (FPI). The results showed that the critical points of this activity are mainly related to the Ecological indicator (2.3) and the Economic indicator (2.8). The best indicator was the Community (3.8). The problems that put at risk the permanence of the activity and its maintenance are: (i) fishing for juveniles; (ii) illegal vessels; (iii) lack of collaboration of the fishing sector with science, and (iv) unreliability of data supplied. All the points mentioned make the snapper fishery on the north coast of Brazil socio-ecologically unsustainable in the long term.

Proxies to detect hotspots of invertebrate biodiversity on rhodolith beds across the Southwestern Atlantic

Rhodolith beds are known worldwide to host high biodiversity to several taxa. Despite their importance, few ecological data explored the influence of rhodolith features and environmental variables on associated biodiversity, a gap that has been hampering the mapping of diversity hotspots and priority areas for conservation. In this study, we investigated large-scale spatial variations of rhodolith beds and their associated fauna, using annelid polychaetes as a biological model. We aimed to identify proxies, based on rhodolith features and environmental variables, to detect biodiversity hotspots across Southwestern Atlantic beds, laying the groundwork for mapping priority areas for conservation. With this goal, we sampled a total of 136 rhodolith nodules across seven sites with beds under distinct latitudes, depths, distances from the mainland coast of Brazil, and rhodolith densities. For each nodule sampled, we measured the volume, diameter, and mass of sediment trapped, as well as the attributes of the associated polychaetes (abundance, richness, diversity, and composition). Our results revealed a complex network of collinearities and synergisms between the rhodolith features and the majority of the polychaetes attributes (i.e., abundance, diversity, and composition). Polychaete richness, in contrast, can be explained by the combination of two proxies: (1) rhodolith nodule diameter and (2) distance of the rhodolith bed from the mainland coast. Nearshore rhodolith beds and larger nodules were associated with higher values of richness. Additionally, rhodoliths with a hollow morphology were also associated with higher values of polychaete richness. These results suggest that nearshore rhodolith beds with large and hollow nodules could be priority areas for conservation. However, further multi-taxa studies using our framework are still needed to explore other regions and scales, delineating more comprehensive proxies for predicting ecological patterns of the rhodoliths associated fauna and to identify priorities for conservation across Southwestern Atlantic beds.

Marine debris provide long-distance pathways for spreading invasive corals

Anthropogenic marine debris and invasive species are pervasive in the ocean. However, research on the mechanisms and dynamics controlling their distribution in marine systems (e.g.; by floating debris acting as vectors for invasive species) is limited. Applying a numerical modeling approach, we demonstrate that rafting invasive corals (Tubastraea spp.) can be transported over long distances and reach important tropical receptor regions. In <180 days, buoyant debris can cover distances between 264 and 7170 km moving from the Brazilian semiarid coast to the Amazon coast and reaching eight regions in the Wider Caribbean (mainly the Eastern Caribbean and Greater Antilles). Analyzing 48 simulated scenarios (4 years × 3 depths × 4 months), we demonstrate that in ~86 % of the scenarios the particles are stranded in the Caribbean and in ~71 % they end up in the Amazon coast. Our results showed litter floating trajectories at 0-10 m water depth, transported every year to the Caribbean province. However, in August this transport is frequently blocked by the retroflection of the North Brazil Current adjacent to the Amazon River estuarine plume. Our results indicate routes for fast and long-distance transport of litter-rafting invasive species. We hypothesized a high risk of bioinvasion on important marine ecosystems (e.g., coral reefs) likely becoming increasingly threatened by these invasive species and debris. This highlights the imperative need for an ocean governance shift in prevention, control, and eradication, not only focused on local actions to prevent the spread of invasive species but also a broad international action to decrease and mitigate marine debris pollution globally.

Incised valleys drive distinctive oceanographic processes and biological assemblages within rhodolith beds

Continental shelves encompass gently sloped seascapes that are highly productive and intensively exploited for natural resources. Islands, reefs and other emergent or quasi-emergent features punctuate these shallow (<100 m) seascapes and are well known drivers of increased biomass and biodiversity, as well as predictors of fishing and other human uses. On the other hand, relict mesoscale geomorphological features that do not represent navigation hazards, such as incised valleys (IVs), remain poorly charted. Consequently, their role in biophysical processes remains poorly assessed and sampled. Incised valleys are common within rhodolith beds (RBs), the most extensive benthic habitat along the tropical and subtropical portions of the mid and outer Brazilian shelf. Here, we report on a multi-proxy assessment carried out in a tropical-subtropical transition region (~20°S) off Eastern Brazil, contrasting physicochemical and biological variables in IVs and adjacent RBs. Valleys interfere in near bottom circulation and function as conduits for water and propagules from the slope up to the mid shelf. In addition, they provide a stable and structurally complex habitat for black corals and gorgonians that usually occur in deeper water, contrasting sharply with the algae-dominated RB. Fish richness, abundance and biomass were also higher in the IVs, with small planktivores and large-bodied, commercially important species (e.g. groupers, snappers and grunts) presenting smaller abundances or being absent from RBs. Overall, IVs are unique and vulnerable habitats that sustain diverse assemblages and important ecosystem processes. As new IVs are detected by remote sensing or bathymetric surveys, they can be incorporated into regional marine management plans as conservation targets and priority sites for detailed in situ surveys.

Dominance of photo over chromatic acclimation strategies by habitat-forming mesophotic red algae

Red coralline algae are the deepest living macroalgae, capable of creating spatially complex reefs from the intertidal to 100+ m depth with global ecological and biogeochemical significance. How these algae maintain photosynthetic function under increasingly limiting light intensity and spectral availability is key to explaining their large depth distribution. Here, we investigated the photo- and chromatic acclimation and morphological change of free-living red coralline algae towards mesophotic depths in the Fernando do Noronha archipelago, Brazil. From 13 to 86 m depth, thalli tended to become smaller and less complex. We observed a dominance of the photo-acclimatory response, characterized by an increase in photosynthetic efficiency and a decrease in maximum electron transport rate. Chromatic acclimation was generally stable across the euphotic-mesophotic transition with no clear depth trend. Taxonomic comparisons suggest these photosynthetic strategies are conserved to at least the Order level. Light saturation necessitated the use of photoprotection to 65 m depth, while optimal light levels were met at 86 m. Changes to the light environment (e.g. reduced water clarity) due to human activities therefore places these mesophotic algae at risk of light limitation, necessitating the importance of maintaining good water quality for the conservation and protection of mesophotic habitats.

Photosynthetic responses of crustose coralline algae recruit from an upwelling area to light intensity, temperature and current flow rate in a mesocosm

The crustose coralline algae (CCA) play an important role building carbonate habitats and enhancing species diversity in rocky shores, rhodolith beds and coral-algal reefs. Though worldwide distributed some taxonomic groups were proved to show light and temperature boundaries. Nevertheless, little is known about the biological limits of CCA recruits and photosynthetic responses in a climate change environment. In this way, experimental studies are essential to identify their optimal conditions development. The aim of the study was to test ideal environmental conditions for CCA recruits from an upwelling area to verify Fv/Fm response patterns as an indicator of photosynthetic performance. Artificial disks were fixed on a rocky shore to provide substrate for CCA recruitments and then moved to be tested in a flow-through system. The CCA tested were species of the Genus Lithophyllum and experiments were performed with CCA exposed to different levels of light, temperature and current flow rates. The photosystem II function, measured by chlorophyll a fluorescence (Fv/Fm), was used as an indicator of potential photosynthetic electron transport. There was an interaction between light intensity, flow rate and temperature. Low light intensity, high temperature and fast flow rate (20 μmol m-2. s-1; 19 and 24 °C; 0.09 m s-1 respectively) provided optimal conditions for CCA recruits.

Amazon River plume habitats shape planktonic cnidarian assemblages in the Western Atlantic

The impact of the Amazon River freshwater plume on planktonic cnidarians over neritic and oceanic provinces is unknown. To provide further knowledge we took advantage of an oceanographic cruise performed in October 2012 in the Western Atlantic off the North Brazilian coast (8°N, 51°W-3.5°S, 37°W). A complex and dynamic system was observed, with strong currents and eddies dispersing the plume over a large area. Our results show that the Amazon River shapes marine habitats with a thin highly productive surface layer compressed by a deeper oxygen minimum zone both over the shelf and in the open ocean. We hypothesized that such habitat structure is particularly advantageous to planktonic cnidarians, which have low metabolic rates, being able to survive in hypoxic zones, resulting in high species richness and abundance. Over the shelf, distinctions were sharp and the area under the influence of the plume presented a diverse assemblage occurring in large abundance, while outside the plume, the hydromedusa Liriope tetraphylla was dominant and occurred almost alone. Divergences in the oceanic province were less pronounced, but still expressive being mostly related to the abundance of dominant species. We concluded that Amazon River plume is a paramount physical feature that profoundly affects the dynamics of the mesoscale habitat structure in the Western Equatorial Atlantic Ocean and that such habitat structure is responsible for shaping planktonic cnidarian assemblages both in neritic and oceanic provinces.

Genetic diversity patterns of lionfish in the Southwestern Atlantic Ocean reveal a rapidly expanding stepping-stone bioinvasion process

In 2020, multiple lionfish (Pterois spp.) records along the equatorial Southwestern (SW) Atlantic revealed a new expansion of these potentially damaging invasive populations, which could impact over 3500 km of Brazilian coastline over the next few years, as well as unique ecosystems and marine protected areas in its path. To assess the taxonomic status, invasion route, and correlation with other centres of distribution, we investigated the genetic diversity patterns of lionfish caught in 2022 at the Amazonia, Northeastern Brazil, and Fernando de Noronha and Rocas Atoll ecoregions, using two molecular markers, the mitochondrial COI and the nuclear S7 RP1. The data indicate that all studied lionfish belong to what is generally accepted as P. volitans, and share the same genetic signature as lionfish present in the Caribbean Sea. The shared haplotypes and alleles indicate that the SW Atlantic invasion derives from an active movement of adult individuals from the Caribbean Sea into the Brazilian coast. The Amazon mesophotic reefs likely served as a stepping-stone to overcome the biogeographical barrier represented by the Amazon-Orinoco River plume. New alleles found for S7 RP1 suggest the onset of local genetic diversification, heightening the environmental risks as this bioinvasion heads towards other South Atlantic ecoregions.

Lessons from the invasion front: Integration of research and management of the lionfish invasion in Brazil

After successful invasions in the Caribbean and Mediterranean, lionfish (Pterois spp.) have recently invaded another important biogeographical region -the Brazilian Province. In this article, we discuss this new invasion, focusing on a roadmap for urgent mitigation of the problem, as well as focused research and management strategies. The invasion in Brazil is already in the consolidation stage, with 352 individuals recorded so far (2020-2023) along 2766 km of coastline. This includes both juveniles and adults, including egg-bearing females, ranging in length from 9.1 to 38.5 cm. Until now, most of the records in the Brazilian coast occurred in the equatorial southwestern Atlantic (99%), mainly on the Amazon mesophotic reefs (15% of the records), northeastern coast of Brazil (45%), and the Fernando de Noronha Archipelago (41%; an UNESCO World Heritage Site with high endemism rate). These records cover a broad depth range (1-110 m depth), twelve protected areas, eight Brazilian states (Amapá, Pará, Maranhão, Piauí, Ceará, Rio Grande do Norte, Paraíba, and Pernambuco) and multiple habitats (i.e., mangrove estuaries, shallow-water and mesophotic reefs, seagrass beds, artificial reefs, and sandbanks), indicating a rapid and successful invasion process in Brazilian waters. In addition, the lack of local knowledge of rare and/or cryptic native species that are potentially vulnerable to lionfish predation raises concerns regarding the potential overlooked ecological impacts. Thus, we call for an urgent integrated approach with multiple stakeholders and solution-based ecological research, real-time inventories, update of environmental and fishery legislation, participatory monitoring supported by citizen science, and a national and unified plan aimed at decreasing the impact of lionfish invasion. The experience acquired by understanding the invasion process in the Caribbean and Mediterranean will help to establish and prioritize goals for Brazil.

An Overview of Rhodoliths: Ecological Importance and Conservation Emergency

Red calcareous algae create bio-aggregations ecosystems constituted by carbonate calcium, with two main morphotypes: geniculate and non-geniculate structures (rhodoliths may form bio-encrustations on hard substrata or unattached nodules). This study presents a bibliographic review of the order Corallinales (specifically, rhodoliths), highlighting on morphology, ecology, diversity, related organisms, major anthropogenic influences on climate change and current conservation initiatives. These habitats are often widespread geographically and bathymetrically, occurring in the photic zone from the intertidal area to depths of 270 m. Due to its diverse morphology, this group offers a special biogenic environment that is favourable to epiphyte algae and a number of marine invertebrates. They also include holobiont microbiota made up of tiny eukaryotes, bacteria and viruses. The morphology of red calcareous algae and outside environmental conditions are thought to be the key forces regulating faunistic communities in algae reefs. The impacts of climate change, particularly those related to acidification, might substantially jeopardise the survival of the Corallinales. Despite the significance of these ecosystems, there are a number of anthropogenic stresses on them. Since there have been few attempts to conserve them, programs aimed at their conservation and management need to closely monitor their habitats, research the communities they are linked with and assess the effects they have on the environment.

Checklist, diversity descriptors and selected descriptions of a highly diverse intertidal sponge (Porifera) assemblage at Costa do Descobrimento (Bahia, Brazil)

Costa do Descobrimento is located in southern Bahia, Brazil, and only 22 species of sponges (Porifera) were known from the area until now, despite its important reef formations. In the present study, we report a checklist of the sponges of Costa do Descobrimento and their distribution in the studied reefs, with several species illustrated in life. We also describe nine new sponge records for this region, some of which are new records for Brazil, or new records of species previously only poorly known. We present alpha and beta diversity indices and compare the sponge assemblage of the sampled locations. Four reefs were considered: two fringing reefs (Arraial D'Ajuda-AA and Coroa Vermelha / Mutá-CVM) and two offshore Municipal Marine Park "Parque Municipal Marinho- (P.M.M. Coroa Alta-CA and P.M.M. Recife de Fora-RF). A total of 229 specimens were collected (224 Demospongiae, 2 Homoscleromorpha and 3 Calcarea). These were classified in 101 morphotypes. Studied materials included representatives of 15 orders, 34 families and 48 genera. The richest orders are Haplosclerida (29 spp.), Poecilosclerida (15 spp.) and Tetractinellida (11 spp.). The richest families were Chalinidae (24 spp.), Clionaidae (7 spp.) and Mycalidae and Suberitidae (6 spp. each). The richest genus is, by far, Haliclona (20 spp.). Only 13 species were shared among all four reefs surveyed, namely Amphimedon viridis, Cinachyrella alloclada, C. apion, Cladocroce caelum, Cliona varians, Dysidea robusta, Mycale (Naviculina) diversisigmata, Niphates erecta, Spirastrella hartmani, Tedania (Tedania) ignis, Terpios fugax, Tethya bitylastra and T. maza. The reefs with the highest richness were CA and CVM, and the lowest richness was observed in RF. The most similar reefs in terms of species composition were CA and CVM, while AA and RF were more dissimilar to the previous reefs, but also from each other. While the difference among CA, CVM and AA was mainly explained by species turnover, RF differed from the previous based on its lower richness (nestedness component). Even though CA and CVM were the richest reefs, AA presented the highest number of exclusive species, highlighting the uniqueness of this reef, and urging the inclusion of local beachrock fringing reefs in a more holistic conservation strategy at Costa do Descobrimento.

Lost characters and lost taxonomists: Coelocarteriidae fam. nov., Poecilosclerida with and without chelae, to accommodate supposed phloeodictyids (Haplosclerida)

The taxonomic study of Great Amazon Reef System sponges yielded three Oceanapia-like (Phloeodictyidae, Haplosclerida) species of similar gross morphology, two preliminarily identified as O. bartschi and another as Coelocarteria (Poecilosclerida), due to the presence of common palmate isochelae. The remarkable overall similarity of all three species in gross morphology necessitated an integrative assessment of the phylogenetic affinities. A selection of haplosclerid and poecilosclerid sequences (18S and 28S rRNA) was gathered from Genbank and compared to sequences mapped to reference from metagenome of two Oceanapia-like species from the Amazon River mouth, one of which matched O. bartschi. Both Brazilian species clustered with Coelocarteria singaporensis (Singapore). These species nest in the Poecilosclerida, far from Oceanapia (sp. and isodictyiformis) and other haplosclerids (Amphimedon, Petrosia, Siphonodictyon and Xestospongia) but also far from the poecilosclerid Isodictya that is currently classified in the same family as Coelocarteria, the Isodictyidae. Specimens with chelae are named Coelocarteria alcoladoi sp. nov. herein, while those without chelae represent the other two species. One matched Inflatella bartschi (O. bartchi’s holotype, here re-examined), thereby supporting the transfer of this species to Coelocarteria. The other is proposed as C. amadoi sp. nov. and is the second known lipochelous species in this genus. The 28S phylogenies recovered Coelocarteria bartschi comb. nov. (formerly Oceanapia bartschi) in the Poecilosclerida clade that clustered with Coelocarteria spp., including the type species of this genus, C. singaporensis, with 100% support. Coelocarteria alcoladoi sp. nov., also without chelae, grouped in the same clade, thereby corroborating the classification in this genus. The clade composed of Coelocarteria spp. grouped with Cornulella sp., suggesting an affinity between these genera. Coelocarteria is currently situated within Isodictyidae and Cornulella in Acarnidae. Isodictya (Isodictyidae) grouped with Amphilectus (Esperiopsidae) with high support and is only distantly related to Coelocarteria. Acarnus (Acarnidae) grouped with Clathria, also with high support, far from Coelocarteria and Cornulella. These results suggest the polyphyletic nature of Isodictyidae and Acarnidae, for which reason we preferred to propose a new, currently monotypic family for Coelocarteria spp., Coelocarteriidae fam. nov. ZooBank: urn:lsid:zoobank.org:pub:71FDB6FD-4A5F-4180-8DA7-79EA4CB615D1

Neospongodes atlantica, a potential case of an early biological introduction in the Southwestern Atlantic

Soft corals (Anthozoa: Octocorallia) are discreet components in the Southwestern Atlantic reef communities. In Brazil, the native octocoral shallow-reef fauna is mostly represented by gorgonians. Consequently, except for the nephtheid Neospongodes atlantica, most of the known soft corals from this region are considered non-indigenous. Hitherto, the monotypic genus Neospongodes, which was proposed in the early 1900s, has been considered to be endemic to the Northeastern Brazilian coast. Herein, based on in situ records, we show that N. atlantica is a substrate generalist that has been probably expanding its distribution by dominating extensive shallow and mesophotic sandy and reef bottoms, generally outcompeting other reef benthic organisms, including Brazilian endemic species. Based on previously unidentified museum specimens, new records, and a broad literature review, we provide the most comprehensive modelling of the potential distribution of this species in the Southwestern Atlantic. Based on molecular inference supported by in-depth morphological analysis, the probable non-indigenous and, therefore, ancient introduction of N. atlantica in Brazilian waters is discussed. Finally, these results support that Neospongodes and the Indo-Pacific Stereonephthya are synonyms, which led us to propose the latter as taxonomically invalid.

A review of the knowledge of reef fish in the Southwest Atlantic

Reef environments are rapidly transforming worldwide, and these changes are causing major impacts to the reef ecosystem. Scientific knowledge is strategic for marine conservation and management in these scenarios. Aiming to contribute to this subject, a systematic review from 1967 to 2020 was conducted, in order to identify gaps in studies regarding reef fish species, ecosystem components and processes. Multidisciplinary sciences concerning reef fish have been rising, mainly in the fields of basic biology and ecology. Besides that, phase shifts and ecosystem services were absent terms in the analyzes of co-occurrence. Research in the ethnosciences needs to be increased, and will improve access to local ecological knowledge, which can be used as a tool to address issues in reef environments. Socio-ecological systems are components of this landscape that has had few publications. The participation in the elaboration of public policies can be a new avenue to foster the biodiversity of reef environments.

Fluxes of the Amazon River plume nutrients and microbes into marine sponges

Sponges have co-evolved with microbes for over 400 myr. Previous studies have demonstrated that sponges can be classified according to the abundance of microbes in their tissues as Low Microbial Abundance (LMA) and High Microbial Abundance (HMA). While LMA sponges rely mainly on water column microbes, HMA appear to rely much more on symbiotic fermentative and autotrophic microbes maintained in their tissues. However, it is unclear if this pattern holds when comparing different species of tropical sponges under extreme nutrient conditions and sediment loads in the water column, such as the Great Amazon Reef System (GARS), which covers an area of ~56,000 km² off the Amazon River mouth. Sponges are the major GARS benthic components. However, these sponges' microbiome across the GARS is still unknown. Here, we investigated water quality, isotopic values (δ¹³C and δ¹⁵N), metagenomic and lipidomic profiles of sponges obtained from different sectors throughout the GARS. >180 million shotgun metagenomic reads were annotated, covering 22 sponge species. Isotopic and lipidomic analyses suggested LMA sponges rely on the Amazon River Plume for nutrition. HMA sponges (N = 15) had higher Roseiflexus and Nitrospira abundance, whereas LMA sponges (N = 7) had higher Prochlorococcus and Pelagibacter abundance. Functional data revealed that the LMA sponge microbiomes had greater number of sequences related to phages and prophages as well as electron transport and photophosphorylation which may be related to photosynthetic processes associated with the Prochlorococcus and Synechococcus found in the LMA. The higher phages abundance in LMA sponges could be related to these holobionts' reduced defense towards phage infection. Meanwhile, HMA sponge microbiomes had higher Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR abundance, which may be involved in defense against phage infection. This study sheds light on the nutrient fluxes and microbes from the Amazon River plume into the sponge holobionts.

Long-term monitoring projects of Brazilian marine and coastal ecosystems

Biodiversity assessment is a mandatory task for sustainable and adaptive management for the next decade, and long-term ecological monitoring programs are a cornerstone for understanding changes in ecosystems. The Brazilian Long-Term Ecological Research Program (PELD) is an integrated effort model supported by public funds that finance ecological studies at 34 locations. By interviewing and compiling data from project coordinators, we assessed monitoring efforts, targeting biological groups and scientific production from nine PELD projects encompassing coastal lagoons to mesophotic reefs and oceanic islands. Reef environments and fish groups were the most often studied within the long-term projects. PELD projects covered priority areas for conservation but missed sensitive areas close to large cities, as well as underrepresenting ecosystems on the North and Northeast Brazilian coast. Long-term monitoring projects in marine and coastal environments in Brazil are recent (<5 years), not yet integrated as a network, but scientifically productive with considerable relevance for academic and human resources training. Scientific production increased exponentially with project age, despite interruption and shortage of funding during their history. From our diagnosis, we recommend some actions to fill in observed gaps, such as: enhancing projects' collaboration and integration; focusing on priority regions for new projects; broadening the scope of monitored variables; and, maintenance of funding for existing projects.

Interconnected marine habitats form a single continental-scale reef system in South America

Large gaps in reef distribution may hinder the dispersal of marine organisms, interrupting processes vital to the maintenance of biodiversity. Here we show the presence and location of extensive reef habitats on the continental shelf between the Amazon Reef System (ARS) and the Eastern Brazilian Reef System (ERS), two reef complexes off eastern South America. Formations located 20-50 m deep include both biogenic and geogenic structures. The presence of diverse reef assemblages suggests the widespread occurrence of rocky substrates below 50 m. These habitats represent an expansion of both the ARS and ERS and the closure of the only remaining large-scale gap (~ 1000 km) among West Atlantic reef environments. This indicates that the SW Atlantic harbors a single, yet heterogeneous, reef system that stretches for about 4000 km, and thus, represents one of the largest semi-continuous tropical marine ecosystems in the world.

Larval dispersal of Brachyura in one of the largest estuarine/marine systems in the world

The Amazon Continental Shelf (ACS) is a complex habitat that receives a large annual freshwater discharge into the ocean, producing a superficial plume and carrying with it large amounts of nutrients to the continental shelf along thousands of kilometers while sustaining high biodiversity in the estuary–ocean continuum. For the first time, this study monitored six sites in a wide transect with approximately 240 km radius on the ACS every 2–4 months. The objectives were (1) to analyze the composition of larval Brachyuran crabs and (2) to predict the importance of environmental parameters (temperature, salinity and chlorophyll-a) in structuring their abundance. A total of 17,759 larvae identified were distributed in 8 families and 24 taxa. The water salinity was the best predictor of larval distribution. The statistical models used indicated that Panopeidae and Portunidae larvae are more frequent and more likely to occur in shallow water layers, while Calappidae occur in deeper layers, and Grapsidae, Ocypodidae, Sesarmidae, Pinnotheridae and Leucosiidae occur similarly in both strata. The larval dispersal extent varies among families and throughout the year while the groups are distributed in different salinities along the platform. The probability of occurrence of Portunidae is higher in ocean water (≥ 33.5); Grapsidae, Panopeidae, and Pinnotheridae is higher in intermediate and ocean salinity waters (25.5 to 33.5); Ocypodidae, Sesarmidae and Calappidae is higher in estuarine and intermediate salinity waters (5 to 25.5), whereas Leucosiidae, euryhaline, occur in all salinities (5 to 33.5). Furthermore, the Amazon River seasonal flow and plume movement throughout the year not only regulate the larval distribution and dispersion of estuarine species but are also fundamental for the ACS species, providing the necessary nutrient input for larval development in the region.

Sponges present a core prokaryotic community stable across Tropical Western Atlantic

Sponges are among the earliest lineages of metazoans, with first fossil records dated back to 890 million years ago. All sponge species present associations with microorganisms to some extension, which influence sponges' survival and adaptation. Sponge species can be divided into two categories, Low Microbial Abundance and High Microbial Abundance, depending on the abundance of the microbial community that they host. Monanchora arbuscula (a Low Microbial Abundance sponge species) and Xestospongia muta (a High Microbial Abundance sponge species) are sponges with widespread distribution in the Tropical Western Atlantic. Despite previous studies on the major features of these species, little is known whether M. arcuscula and X. muta prokaryotic communities are stable across vast geographic regions. We obtained a total of ~9.26 million 16S rRNA gene Illumina sequences for M. arbuscula samples collected at seven locations and for X. muta samples collected at three locations, corresponding to five ecoregions of the Caribbean and the Southwestern Atlantic (N = 105, 39 from M. arcuscula and 66 from X. muta). These samples reflected different ecological strategies for prokaryotic communities assembly, since the core prokaryotic communities of M. arbuscula are more heterotrophic and shared with different sources (corals, sponges, seawater, sediments), while X. muta has more significant photosynthetic prokaryotic communities, mainly outsourced from other sponges. Results of M. arbuscula and X. muta prokaryotic communities analysis demonstrate that both sponge species have core prokaryotic communities stable across a vast geographic area (> 8000 km), and the world's most notable coastal marine biogeographic filter, the Amazon River Mouth, in spite of the significant differences found among transient prokaryotic communities of both sponge species.

Human risk assessment of toxic elements (As, Cd, Hg, Pb) in marine fish from the Amazon

The present study evaluated As, Hg, Pb and Cd burdens in both ecologically and commercially important 314 marine fishes belonging to 47 species sampled along the Amazon Coast. We specifically investigated variations in these four elements among different habitats and their relationships with trophic position and estimated potential human health risk by calculating the hazard quotient (HQ), hazard index (HI), and target cancer risk (TR). Our analyses revealed that Hg concentrations in reef-associated fish were over 2-fold those recorded in demersal fish (p < 0.001). A stable isotope analysis indicated that most of the fish species analyzed herein are secondary consumers (i.e., TP > 2.9) and their trophic positions exhibited a significant negative correlation to As, Pb and Cd. Positive significant relationships were noted between As-Cd, As-Pb, As-Hg, Hg-Cd and Cd-Pb, suggesting that these elements exhibit similar dispersion properties and bioaccumulation homology, probably arising from natural fluvial inputs from the Amazon basin system. Detected As concentrations were higher than established guidelines and legal limits in 63.8% of the examined species (n = 30), whereas Cd, Hg and Pb levels were generally very low. Estimated daily intake (EDI) of iAs, Hg and Pb were above reference dose (RfD) in more almost half of species analyzed and HQ values were each found to pose potential non-carcinogenic health risks if high amounts are consumed over time. HI indicates that the determined elements attained levels considered as potential human health hazards trough consumption of eight cartilaginous fish. The TR values of iAs and Pb were higher than the guideline value and given this, individuals who continuously consume cartilaginous fish contaminated with the toxic elements determined here will likely be under increased cancer risks in the long term.

Global assessment of coralline algae mineralogy points to high vulnerability of Southwestern Atlantic reefs and rhodolith beds to ocean acidification

Coralline algae constitute one of the main groups of highly vulnerable calcified benthic organisms to ocean acidification. Although damaging effects of seawater acidification on the coralline algae skeleton have been widely demonstrated, the susceptibility to dissolution varies according to the Mg²⁺ in the calcite lattice. Even though the Southwest Atlantic Ocean exhibits the world's largest rhodolith beds, which occupies 20,902 km², there is no information regarding the coralline algae species mineralogy in this area. Here, we provide mineralogical data of twenty-four coralline algae species, examine the similarity in taxonomic groups, spatial occurrence and the vulnerability of these algae to seawater acidification. Mineralogy revealed that coralline algae skeletons were mainly composed of high-Mg calcite (> 70%) with minor presence of aragonite (< 30%) and dolomite (< 3%). There were no similarities between the skeletal mineralogy of taxonomic groups and sampling regions. Remarkably, the mean Mg-substitution of encrusting coralline algae from the Brazilian Shelf was 46.3% higher than global average. Because of the higher mean Mg-substitution in calcite compared with worldwide coralline algae, these algae from Southwest Atlantic Ocean would be highly susceptible to dissolution caused by the expected near-future ocean acidification and will compromise CaCO₃ net production across the Brazilian Shelf.

Western boundary currents drive sun-coral (Tubastraea spp.) coastal invasion from oil platforms

Most marine species have a planktonic larval phase that benefit from the surface oceanic flow to enhance their dispersion potential. For invasive species, the interaction of environmentally resistant larvae with different flow regimes and artificial substrates can lead to complex larval dispersion patterns and boost geographic expansion. In the Southwest Atlantic, the invasive corals Tubastraea spp. (sun-coral) have been recorded biofouling on oil platforms since the late 1980s. These platforms are considered important vectors for the established populations throughout the Brazilian coast. However, we still do not know how the position of these structures relative to regional flow contribute to the natural dispersion potential of these invaders on a regional scale. Herein, we used an eddy-resolving ocean model (ROMS) and an Individual Based Model (IBM-Ichthyop) to simulate the natural dispersion patterns of sun-coral larvae from all oil platforms on Brazilian oil-producing basins, for the austral summer and winter along 6 years (2010–2015) in 90-day simulations. We found that mortality rates by advection were significantly higher during the winter (p = 0.001) and when sources of larvae were compared throughout this season (p = 1.9 × 10^–17). The influence of two western boundary currents and persistent eddy activity contribute to the dispersal of larvae to distances up to 7000 km. The effectiveness of each oil-producing basin as vectors for the entire Brazilian coastline, measured as the percentage of larval supply, highlights the importance of the northern Ceará (59.89%) and Potiguar (87.47%) basins and the more central Camamu (44.11%) and Sergipe-Alagoas (39.20%) basins. The poleward shift of the Southern branch of the South Equatorial Current during the winter causes larvae released from the Sergipe-Alagoas and Camamu basins to enter the North Brazil Current, expanding their dispersion towards the north. The Brazil Current disperses larvae southwards, but strong mesoscale activity prevents their dispersion to the coast, especially for those released from the oil platforms on Campos and Santos basins. Within this complex hydrodynamic setting, a few source areas, like those in the Sergipe-Alagoas and Camamu basins, can potentially contribute to the spread of larvae along nearly all the Brazilian coast. Therefore, oil platforms act as possible chronic sources of sun-coral propagules to the coast, emphasizing the urgency for a more detailed set of actions to control and monitor these invasive exotic species.

The influence of the Doce River mouth on the microbiome of nearby coastal areas three years after the Fundão Dam failure, Brazil

The failure of the Fundão Dam, considered the world's largest mining disaster, released more than 55 million m³ of ore tailings into the environment. The sediment plume formed by water and tailings spread along approximately 663 km of water bodies of the Doce River basin. It reached the Atlantic Ocean sixteen days after the dam failure. However, the effects of the dam failure in the marine coastal areas years after the disaster are still unknown. This study aims to evaluate water and sediment microbial communities of nearby coastal areas three years after the Fundão Dam failure, using 16S rRNA gene amplicon sequencing. A total of 441 samples from 25 locations were collected during two different seasons (dry and rainy). The results showed that the Doce River mouth seems to divide the microbial communities from the southern and northern stations into two groups. The plume of sediments from the Doce River seems to be impacting the marine microbiome even at the furthest sampling stations. Bacterial (Anaerolineaceae, Thermodesulfovibrionia and Rhodopirellula) and Archaeal (Bathyarchaeia and Woesearchaeia) taxa, found in high abundance in the sediment of the Doce River mouth, have been previously described in high abundance in heavy metal contaminated sediments, including the Doce River itself and in mine tailing sediments. Cyanobium, found in great abundance in the water samples from the Doce River mouth, was also reported as the most abundant in the water of the Doce River after the Fundão Dam failure. Overall, the farther from the Doce River mouth the sample was, the lower the relative abundances of these taxa were. These results provide strong evidence that the sediment plume released by the Fundão Dam failure is probably impacting the marine microbiome of nearby coastal areas, even three years after the dam failure.

The Amazon River plume, a barrier to animal dispersal in the Western Tropical Atlantic

The dispersal of marine organisms can be restricted by a set of isolation mechanisms including hard barriers or hydrological features. In the Western Atlantic Ocean, the Amazon River discharge has been shown to act as a biogeographical barrier responsible for the differences in reef fish communities between Caribbean Sea and Northeast Brazil continental shelves. Here, we compare the diversity of all Animalia phyla from biogeographic ecoregions along the Tropical Western Atlantic continental shelf to test the hypothesis that the Amazon River plume spatially structures species diversity. For that, we used beta diversity estimators and multivariate ecological analysis on a database of species occurrence of the whole animal kingdom including 175,477 occurrences of 8,375 species from six ecoregions along the Western Tropical Atlantic. Results of the whole animal kingdom and the richest phyla showed that the Caribbean Sea and Tropical Brazil ecoregions are isolated by the Amazon River Plume, broadening and confirming the hypothesis that it acts as a soft barrier to animal dispersal in the Western Tropical Atlantic. Species sharing is larger northwestwards, in direction of the Caribbean than the opposite direction. Beyond species isolation due to local characteristics such as low salinity and high turbidity, our results suggest the dominant northwestward currents probably play a major role in animal dispersion: it enhances the flux of larvae and other planktonic organisms with reduced mobility from Brazil to Caribbean and hinders their contrary movement. Thus, the Amazon area is a strong barrier for taxa with reduced dispersal capacity, while species of pelagic taxa with active swimming may transpose it more easily.

Rocky reef fish biodiversity and conservation in a Brazilian Hope Spot region

Abstract Coastal islands of Grande Rio, located south Rio de Janeiro and Maricá cities have been under multiple anthropogenic impacts. Despite these problems, these insular systems shelter a high diversity of fish species. Reef fishes are essential components of tropical marine coastal communities, also providing food and income for millions of people around the world. In this work, we generated an updated checklist from Cagarras Islands Natural Monument and surrounding areas based on fisheries data, literature records and multiple sampling techniques, including the Submersible Rotating Video technique, used for the first time in Brazil. We present an inventory of 282 fish species representing 91 different families, with 21 new records for the study area, including a non-native species (Heniochus acuminatus). In addition, our results show a moderate endemism level for the Brazilian province (approximately 6.0%), while 10.5% of species are assigned to one of IUCN’s threatened categories. Our efforts show the fish biodiversity scenario and their distribution on coastal islands more than 10 years after the Cagarras Islands Natural Monument establishment, reinforcing the importance of monitoring research programs for the management of this Marine Protected Area and surrounding waters, that play a key role for artisanal fisheries.

Understanding the Impacts of Blue Economy Growth on Deep-Sea Ecosystem Services

The deep sea is the vastest environment on Earth and provides many services and goods. Understanding the services and goods of deep-sea ecosystems would enable better resource governance and decision-making. In the present study, we reviewed and assessed deep-sea ecosystems services using the Ma conceptual framework, which incorporates ecosystems services and goods with human welfare. We also analyzed and measured the scientific production between 2012 and 2021 using the Dimension dataset. The bibliometric analysis showed a lack of studies related to deep-sea ecosystem services, which suggest the urgent need to overcome the existing knowledge gap regarding deep-sea components. However, the current knowledge revealed the crucial role that these ecosystems provide to the planet. Furthermore, we highlighted that there are common services and goods, and every ecosystem service feeds into another one. Developing actions and policies based on approaches that combine all deep-sea ecosystems services and goods are needed for the sustainable growth of the deep-sea economy in accordance with the United Nations Development Goal 14: Life Below Water.

Lobster Distribution and Biodiversity on the Continental Shelf of Brazil: A Review

The continental shelf of Brazil is home to a wide range of lobster species, with varying body size, color, habitat preference, and geographic and bathymetric distribution. Spiny lobsters (Panulirus) and slipper lobsters (Scyllaridae) are exploited for export and for the domestic market. Deep sea lobsters (Nephropidae and Polychelidae) have no commercial potential, and little is known about their biology. In this review, we identified 24 lobster species from benthic ecosystems off Brazil (Palinuridae 25%, Scyllaridae 29%, Nephropidae 25%, Polychelidae 17%, Enoplometopidae 4%). We designed a simplified theoretical scheme to understand the role of lobsters in the ecosystem, based on available evidence of distribution, biodiversity, life cycle, connectivity, and abundance. Finally, we propose a theoretical scheme of trophic top-down control, with interactions between a large decapod (spiny lobster), a demersal predator (red snapper), an apex predator (small tuna), benthic invertebrates and fishing exploitation.

A New Species of Amphipod Pariphinotus Kunkel, 1910 (Amphipoda: Phliantidae) from the Southwestern Atlantic

The genus Pariphinotus Kunkel, 1910 comprises a total of six species around the world, with circumtropical and subtropical distribution, commonly occurring in shallow waters, in soft bottoms and algae, including a previous record of P. seclusus (Shoemaker, 1933) from Brazil. Material examined was collected by SCUBA diving, from rhodolith beds, 12 meters deep, at the Fernando de Noronha Archipelago, off the northeastern Brazilian coast. The new Brazilian species described here can be diagnosed by a unique combination of character states present in other species of the genus. However, it has two exclusive characteristics, distinguishing it from the group: medial apex of pleopod 3 peduncle with two small hook setae, and uropod 1 peduncle not exceeding the apex of telson.

Taxonomy of Petrosiidae Van Soest, 1980 (Haplosclerida, Porifera) from Brazil

Petrosiidae (Haplosclerida, Demospongiae) is characterized by the hard and friable consistency, and an isotropic reticulated skeleton of oxeas/ strongyles. The Brazilian coast and oceanic islands harbor three out of four known genera of Petrosiidae: Neopetrosia de Laubenfels, 1949; Petrosia (Petrosia) Vosmaer, 1885 and Xestospongia de Laubenfels, 1932. A taxonomic survey of samples from several expeditions housed at the Porifera Collection of Museu Nacional, Universidade Federal do Rio de Janeiro, with additional comparative materials obtained from the Museu de Cincias Naturais, Fundao Zoobotnica do Rio Grande do Sul, and Universidade Federal de Pernambuco enabled the description of two new species: P. (P.) revizee sp. nov. and X. dorigo sp. nov. We also recorded a range extention for Neopetrosia proxima and Xestospongia muta, and Xestospongia grayi was synonymized with X. muta. Other species reported from the country are diagnosed, and an identification key for Petrosiidae from Brazil is provided.

Turbid Coral Reefs: Past, Present and Future—A Review

Increasing evidence suggests that coral reefs exposed to elevated turbidity may be more resilient to climate change impacts and serve as an important conservation hotspot. However, logistical difficulties in studying turbid environments have led to poor representation of these reef types within the scientific literature, with studies using different methods and definitions to characterize turbid reefs. Here we review the geological origins and growth histories of turbid reefs from the Holocene (past), their current ecological and environmental states (present), and their potential responses and resilience to increasing local and global pressures (future). We classify turbid reefs using new descriptors based on their turbidity regime (persistent, fluctuating, transitional) and sources of sediment input (natural versus anthropogenic). Further, by comparing the composition, function and resilience of two of the most studied turbid reefs, Paluma Shoals Reef Complex, Australia (natural turbidity) and Singapore reefs (anthropogenic turbidity), we found them to be two distinct types of turbid reefs with different conservation status. As the geographic range of turbid reefs is expected to increase due to local and global stressors, improving our understanding of their responses to environmental change will be central to global coral reef conservation efforts.

Retirement risks: Invasive coral on old oil platform on the Brazilian equatorial continental shelf

The objective of this study was to report, for the first time, the presence of an invasive coral (Tubastraea tagusensis) in an oil platform on the Brazilian equatorial continental shelf. This structure is located more than 1200 km north from other oil and gas structures colonized by this coral. We also discussed the retirement and decommissioning of old biofouling-encrusted oil and gas platforms (~62 platforms) from decreased production and the current oil crisis, exacerbated by the COVID-19 pandemic. This presents an ecological concern due invasive coral range expansion and potential impacts to poorly studied ecosystems such as marginal shallow-water coral reefs and mesophotic ecosystems. It is imperative that mindful risk analysis and rigorous environmental studies must precede the installation of new oil and gas platforms. In addition, decommissioning of retired structures should take into consideration marine restoration and non-indigenous species dispersal, and more specifically, Tubastraea bioinvasion.

Conserved rhodolith microbiomes across environmental gradients of the Great Amazon Reef

The Great Amazon Reef System (GARS) covers an estimated area of 56,000 km² off the mouth of the Amazon River. Living rhodolith holobionts are major benthic components of the GARS. However, it is unclear whether environmental conditions modulate the rhodolith microbiomes. Previous studies suggest that environmental parameters such as light, temperature, depth, and nutrients are drivers of rhodolith health. However, it is unclear whether rhodoliths from different sectors (northern, central, and southern) from the GARS have different microbiomes. We analysed metagenomes of rhodoliths (n = 10) and seawater (n = 6), obtained from the three sectors, by illumina shotgun sequencing (total read counts: 25.73 million). Suspended particulate material and isotopic composition of dissolved organic carbon (δ¹³C) indicated a strong influence of the Amazon river plume over the entire study area. However, photosynthetically active radiation at the bottom (PARb) was higher in the southern sector reefs, ranging from 10.1 to 14.3 E.m^-2 day^-1. The coralline calcareous red algae (CCA) Corallina caespitosa, Corallina officinalis, Lithophyllum cabiochiae, and Hapalidiales were present in the three sectors and in most rhodolith samples. Rhodolith microbiomes were very homogeneous across the studied area and differed significantly from seawater microbiomes. However, some subtle differences were found when comparing the rhodolith microbiomes from the northern and central sectors to the ones from the southern. Consistent with the higher light availability, two phyla were more abundant in rhodolith microbiomes from southern sites (Bacteroidetes, and Cyanobacteria). In addition, two functional categories were enhanced in southern rhodolith microbiomes (iron acquisition and metabolism, and photosynthesis). Phycobiliprotein-coding genes were also more abundant in southern locations, while the functional categories of respiration and sulfur metabolism were enhanced in northern and central rhodolith microbiomes, consistent with higher nutrient loads. The results confirm the conserved nature of rhodolith microbiomes even under pronounced environmental gradients. Subtle taxonomic and functional differences observed in rhodolith microbiomes may enable rhodoliths to thrive in changing environmental conditions.

Decadal (2006-2018) dynamics of Southwestern Atlantic's largest turbid zone reefs

Tropical reefs are declining rapidly due to climate changes and local stressors such as water quality deterioration and overfishing. The so-called marginal reefs sustain significant coral cover and growth but are dominated by fewer species adapted to suboptimal conditions to most coral species. However, the dynamics of marginal systems may diverge from that of the archetypical oligotrophic tropical reefs, and it is unclear whether they are more or less susceptible to anthropogenic stress. Here, we present the largest (100 fixed quadrats at five reefs) and longest time series (13 years) of benthic cover data for Southwestern Atlantic turbid zone reefs, covering sites under contrasting anthropogenic and oceanographic forcing. Specifically, we addressed how benthic cover changed among habitats and sites, and possible dominance-shift trends. We found less temporal variation in offshore pinnacles' tops than on nearshore ones and, conversely, higher temporal fluctuation on offshore pinnacles' walls than on nearshore ones. In general, the Abrolhos reefs sustained a stable coral cover and we did not record regional-level dominance shifts favoring other organisms. However, coral decline was evidenced in one reef near a dredging disposal site. Relative abundances of longer-lived reef builders showed a high level of synchrony, which indicates that their dynamics fluctuate under similar drivers. Therefore, changes on those drivers could threaten the stability of these reefs. With the intensification of thermal anomalies and land-based stressors, it is unclear whether the Abrolhos reefs will keep providing key ecosystem services. It is paramount to restrain local stressors that contributed to coral reef deterioration in the last decades, once reversal and restoration tend to become increasingly difficult as coral reefs degrade further and climate changes escalate.