Mangroves provide coastal protection, nursery habitat, nutrient retention and long-term carbon storage, yet national-scale mangrove information remains incomplete in many Small Island Developing States (SIDS), where forests are often narrow, fragmented and difficult to resolve using medium-resolution satellite products alone. This study presents a comprehensive national mangrove atlas for mainland Mauritius, developed from island-wide ground surveys, GPS-referenced site documentation, manually digitised mangrove polygons and district-level geospatial synthesis. Mangrove coverage maps were baseline-validated using 2019 field data and Google Earth Pro imagery. Subsequent 2026 update integrated latest available remote sensing data with sporadic field-truthing visits. The atlas identifies 244.5 ha (~2.445 km²) of mangroves distributed across the seven coastal districts, with strong spatial concentration in the eastern coastal areas, namely, Riviere du Rempart and surrounding islets (~92.80 ha; ~38.0%), Flacq and surrounding islets (~60.62 ha; ~24.8%) and Grand Port (~55.73 ha; ~22.8%). Boundary sensitivity analysis produced an indicative boundary-derived area envelope of ±24.9 ha (~10.2%). Field validation confirmed that mangroves occur as estuarine stands, lagoon fringes, hypersaline or saltpan-associated patches, islet mangals and restored stands. The atlas provides a reproducible spatial baseline for environmental impact assessment, restoration prioritisation, post-disaster monitoring and future national blue carbon accounting. We show that field-validated ecological atlases remain essential scientific infrastructure for SIDS, where mangrove systems are small in area but disproportionately important for coastal resilience and climate governance. Recent mapping upgrade indicates that the mapped mangrove extent increased by ~12.81% as compared to data captured in 2019. Using stable, mature stands as a predictive proxy, the mangrove extent yields an overall screening-level estimate of approximately 21,829.3 t AGB, corresponding to ~33,617.5 t CO₂e, and ~10,234.3 t BGB, corresponding to ~15,775.2 t CO₂e. Surface sediment carbon was estimated separately at ~0.25 t organic C per tonne of surface sediment, corresponding to ~0.71 t CO₂e.
Microplastics are ubiquitous in aquatic ecosystems and raise concerns due to their persistence and potential toxicity. Given their known impacts on marine species and the use of bivalves as sentinel species for contamination monitoring, this study aimed to experimentally investigate the selectivity of the brown mussel Perna perna (Linnaeus, 1758) when exposed to the chlorophyte microalga Tetraselmis sp. F. Stein, 1878 and plastic microbeads of similar morphology and size. The study hypothesis is that when microplastics resemble natural food in shape and size, P. perna can discriminate between particles, preferentially ingesting microalgae and rejecting microplastics. Experiments included three treatments in triplicate: microalgae only (MA), polystyrene microbeads only (MB), and a 1:1 mixture of microalgae and polystyrene microbeads (MA+MB). Aliquots were collected at the beginning and end of the incubation period and quantified using an optical microscope. Clearance and ingestion rates were calculated for each replicate, and mean values were determined. Although ingestion rates did not differ significantly among treatments, the clearance rate was significantly higher in the MB treatment (627.07 mL g dw-1 h-1) than in MA (270.59 mL g dw-1 h-1) and MA+MB (518.39 mL g dw-1 h-1), suggesting increased filtering activity. Ingestion rates ranged from 6.80 x 104 to 1.22 x 105 particles g dw-1 h-1 across treatments. Mussels ingested microbeads regardless of microalgal availability, indicating no particle selectivity. Hence, the study hypothesis was not supported. Ecologically, this inability to discriminate among particles may have detrimental consequences for mussels. A similar pattern may occur in natural environments, where microplastics are present in the water column of coastal areas and interact with plankton and suspended organic particles, facilitating ingestion and subsequent contamination.
This study employed a comprehensive approach involving field sampling, grain-size analysis, physicochemical measurements, CT scanning and three-dimensional reconstruction in order to investigate the intertidal flats of the Pearl River Delta (PRD). As Perinereis is an important group of bioindicators in relation to environmental factors, sedimentological and ichnological analyses were conducted at 6 out of 63 stations. These analyses aimed to clarify the composition and distribution characteristics of Perinereis traces, reveal their response relationships with physicochemical factors including sediment grain size, salinity, turbidity and total organic carbon (TOC) content, and further illustrate their environmental significance. The results showed that: (1) Perinereis traces are predominantly composed of grazing and dwelling burrows. These burrows display diverse morphologies, including simple cylindrical, Y-shaped, U-shaped and complex branching networks. Some branches exhibit swellings at junctions. (2) Salinity has a significant influence on the burrow diameter of Perinereis, exhibiting a positive correlation in the low to moderate salinity range (0.28–3.97 PSU). Perinereis growth plateaus when salinity exceeds a threshold of approximately 18 PSU, indicating a physiological tolerance limit. (3) Burrow diameter and sediment bioturbation exhibit no significant correlations with sediment grain size, salinity, turbidity or total organic carbon content. This may be attributed to infaunal interactions (e.g. associations with Macrophthalmus japonicus) and the combined influence of multiple environmental factors. This study improves our understanding of the biology and ichnology of modern Perinereis traces. It provides a quantitative basis for interpreting the interactions between infauna and their environment in intertidal flat ecosystems.
This study investigated the growth patterns, mortality rates, and exploitation rate of the short-necked clam Paratapes undulatus (Born, 1778) in Ba Lua Archipelago, An Giang Province, Southwestern Sea of Viet Nam, using biological data. It was conducted from November 2022 to September 2023. A total of 1,140 individuals were randomly sampled from clam dredge landings for biological analysis. The length-weight relationship showed a negative allometric growth (b < 3), indicating that shell length increased proportionally faster than the body weight. The estimated von Bertalanffy Growth parameters were Loo = 53.6 mm, K = 0.91 year(-1), t(0) = -0.149, and tmax = 4.2 year and the growth performance index Phi ' = 3.417. The estimated mortality rates were Z = 3.80 year(-1), M = 1.47 year(-1), F = 2.34 year(-1). The exploitation rate (E = 0.61) indicates that the stock is currently fully exploited. These findings emphasize the need for management measures to ensure the sustainable exploitation of this commercially valuable species.
ABSTRACT This study uses 21 years (2004-2024) of water level measurements carried out by the IBGE’s Brazilian Continuous Monitoring Network (RBMC), in association with the Global Sea Level Observing System (GLOSS), with the aim of quantifying the temporal variability of the water level, identifying long-term trends in mean sea level, and determining the present spatial extent of tidal inundation of the suburban areas of Salvador. Harmonic, statistical, and spectral analyses, complemented by numerical modeling of the hydrodynamics, show that the sea level is rising at a rate of 2.15 mm/yr and the inundation time is increasing. Important seasonal variability is observed, with higher mean sea levels occurring in April and May driven mainly by the wind stress, whose interannual variation also causes alternating interannual MSL trends. The data indicate an increase in the frequency and severity of extreme high sea level events, regularly associated with the passage of subtidal waves that have become higher and more frequent over the years. Numerical simulations showed that subtidal oscillations tend to be amplified inside the estuary, likely increasing the severity of inundation events. A suburban area of 0.497 km2 along the bay margin of Salvador, with poor infrastructure, experiences more intense tidal inundation approximately every 4.4 years.
ABSTRACT This study investigates the whistle characteristics of six delphinid species in the Southwestern Atlantic Ocean and develops a classification algorithm to distinguish among them. Acoustic recordings were collected along the coast of São Paulo for common dolphins (Delphinus delphis), orcas (Orcinus orca), Atlantic spotted dolphins (Stenella frontalis), and common bottlenose dolphins (Tursiops truncatus). Recordings of spinner dolphins (Stenella longirostris) were obtained from the Fernando de Noronha Archipelago, while Guiana dolphins (Sotalia guianensis) were recorded in the Cananéia Estuary, in southern São Paulo. A total of 1,797 whistles were analyzed using seven acoustic parameters: duration (ms), and minimum, maximum, delta, center, initial, and final frequencies (kHz). These acoustic features were classified using a Random Forest algorithm, which achieved an overall classification accuracy of 55%. The highest accuracy was observed for D. delphis (73.6%), followed by S. guianensis (65%) and S. frontalis (55%). These findings represent a meaningful step toward the development of whistle classification tools and support the potential use of passive acoustic monitoring for long-term studies of delphinid populations in the Southwestern Atlantic Ocean.
Microplastic pollution has become an urgent threat to marine ecosystems, but its effects on coral reefs, especially in highly biodiverse areas such as the Philippines remain largely unknown. This is the first report on the microplastic contamination in the coral reef ecosystem in Lawigan, Bislig, Surigao del Sur, Philippines. Seawater, sediment, fish, and corals (including Acropora and Pocillopora species) were analyzed for microplastics according to standardized methodology. These samples were subjected to chemical digestion (10% KOH), density separation (NaCl), and filtration, and the particles were characterized by microscopy and FTIR spectroscopy. Seawater was noted to contain 60 microplastic particles (0.17 MP particles m(-3)) with the dominance of polypropylene (PP, 21.7%) and polyethylene (PE-HD, 18.3%), and 83.9% of reef fish had microplastics in their digestive tract (mean: 1.5 particles/individual), with films and fibers being the most prevalent shape. Corals contained up to 5 particles/ individual, including particles embedded in tissues, whereas reef sediments contained larger fragments (>1000 mu m) at 0.037 particles g(-1). The dominance of fishing gear polymers (PP/PE) suggests local anthropogenic origins. The microplastics in Philippine coral reefs may add to the burden on these ecosystems, which are already in danger from climate change and overfishing. This study sets baseline data that can be critically used to reduce the impact of anthropogenic factors (such as the use of non-eco-friendly fisheries practices) and to promote community-based monitoring.
Mesopelagic fishes play a central role in marine carbon export and trophic dynamics, with lanternfishes (Myctophidae) representing one of the most abundant and diverse vertebrate groups in the world s oceans. Despite their ecological significance, quantitative relationships between otolith size and body size remain poorly documented for many mesopelagic taxa, limiting their application in dietary studies and palaeontological reconstructions. In this study, we examined sagittal otoliths from nine Myctophidae species (Ceratoscopelus warmingii, Dasyscopelus obtusirostris, Diaphus dumerilii, D. hudsoni, D. perspicillatus, Hygophum hygomii, Lepidophanes guentheri, Notoscopelus caudispinosus, and N. resplendens) collected along the Southeastern Brazilian continental margin between 1996 and 1999. Otoliths were digitally imaged, and morphometric parameters, including otolith length (OL) and width (OW), were measured to assess their relationship with total length (TL) and standard length (SL) using linear regression analyses. Significant positive correlations were observed between otolith dimensions and fish length for most species. Both OL and OW were reliable predictors of TL and SL, except for L. guentheri and N. resplendens. This study provides new regression data that are likely to greatly facilitate the estimation of myctophid size in dietary and paleontological studies.
Meiofauna comprises small benthic metazoans that play a crucial role in aquatic ecosystems and reflect the ecological condition of marine, estuarine, and freshwater environments. In this study, intertidal meiobenthic communities were examined across three coastal environment types along the Uruguayan coast (freshwater, estuarine, and oceanic), and the influence of anthropogenic impact on biodiversity and community structure was evaluated. Three pairs of dissipative sandy beaches were sampled (one impacted and one less impacted per environment type), and the main meiobenthic taxa were quantified and richness, Shannon diversity, Pielou's evenness, total abundance, and nematode abundance were calculated. Physicochemical water variables (dissolved oxygen and pH) and sediment characteristics (mean grain size and organic matter content) were also measured. Generalized linear models showed that biodiversity indices were significantly associated with sediment properties and water parameters, with richness and abundance increasing in finer sediments and with higher organic matter content, and diversity and evenness decreasing under higher organic enrichment. Dissolved oxygen was positively related to richness, Shannon exponential diversity, and evenness. Nematodes, copepods, gastrotrichs, turbellarians, and nauplii dominated the assemblages, with nematodes being the most abundant group overall. Multivariate analyses (NMDS based on Bray-Curtis dissimilarities, PERMANOVA, and beta-dispersion) revealed a clear structuring of communities according to environmental type and the level of anthropogenic impact. In particular, less impacted beaches exhibited a more homogeneous community composition (lower dispersion), whereas impacted beaches showed greater heterogeneity (higher dispersion), reflecting increased variability in composition among their samples. Indicator value analysis identified taxa associated with specific environments and impact levels. Overall, these results highlight that meiobenthic disturbance, supporting the use of meiofauna as a sensitive tool for coastal ecosystem assessment.
This study evaluated the productive performance and economic feasibility of intensive indoor culture of Penaeus vannamei in 2,500 L fiberglass tanks, comparing a recirculating aquaculture system (RAS) and a biofloc technology system (BFT). A 56-day experiment was performed at a stocking density of 750 ind/m3, with four replicates per treatment. Shrimp reared in RAS showed significantly superior growth, reaching greater total length (8.73 +/- 1.72 cm) and final body weight (11.22 +/- 0.74 g) than those cultured in BFT (5.94 +/- 1.29 cm and 9.91 +/- 0.71 g, respectively; p = 0.004 and p = 0.002). Feed conversion ratio was significantly lower in RAS (1.42 +/- 0.12) than in BFT (1.89 +/- 0.15; p = 0.0006), resulting in higher productivity (10.8 +/- 0.54 vs. 8.6 +/- 0.42 kg/ m3; p = 0.0003). Survival did not differ significantly between systems (86.7 +/- 2.52% in RAS and 84.1 +/- 3.21% in BFT; p = 0.21). Inferior performance of BFT was attributed to limitations associated with small-volume tanks, particularly suspended solids accumulation and biofloc instability which likely impaired oxygen availability and feed utilization. Conversely, RAS provided greater environmental stability, supporting more efficient biomass deposition and consistent growth. An economic analysis based on RAS performance and extrapolated to a commercial-scale scenario estimated an annual production cost of US$ 24,249.24 for six production cycles. Feasibility was confirmed by internal rates of return ranging from 19.12% to 68.01% and net present values between US$ 5,290.48 and US$ 49,226.62, depending on shrimp survival (80-90%) and market price (US$ 7.008.00 kg-1). Under optimal conditions, the payback period was 1.8 years. Overall, RAS showed clear biological and economic advantages over BFT for intensive shrimp farming with reduced water use.
The Projeto de Monitoramento de Praias (PMPs) in Brazil is the world's largest marine tetrapod stranding monitoring program, covering over 3000 km of coastline. PMPs are organized as four monitoring programs, executed by a number of institutions, with the primary aim of assessing possible impacts of the oil and gas industry (O&G) on marine tetrapods. Since 2015, data recorded by all PMPs have been stored in a single database with public access. We undertook a literature review to gather all peer-reviewed publications from 2010-2023 using data from PMPs. We summarized 139 publications to investigate: (i) temporal trends in the number of publications; (ii) subject areas from those publications; (iii) taxonomic groups and species studied; (iv) the participation of non-executing institutions based on author affiliations. In addition, we explored whether species ranked higher in conservation assessments were more represented in the publications. Overall, the PMPs have a high number of publications considering their relatively recent implementation when compared to longer stranding monitoring programs. The open-access nature of the PMP database seems to be a catalyst for research, including one-third of publications being authored only by non-executing institutions. The program with the most publications was the PMP-BS (Bacia de Santos), which may result from a larger monitored area, higher numbers of strandings and research institutions than other monitoring programs, and higher mortality due to higher human density. The number of publications was similar across taxonomic groups (sea turtles, seabirds, and marine mammals), which together studied 61 species. Notably, the studies addressed a variety of topics, suggesting that PMPs contribute not only to monitor the impacts of the O&G, but also to increase our understanding of the distribution, ecology, and health of several species. Therefore, continuing PMPs is essential to monitor long-term trends, inform strategies, and support effective management of marine tetrapods.
Katsuwonus pelamis is a fish resource of high economic value and widely used in the fish processing industry, mainly for canned products. This study aimed to identify the parasitic fauna of Katsuwonus pelamis by morphological methods, to analyze the potential impact on industry and consumers. For the evaluation of parasitological contamination, fifty-three animals were visually inspected and the structures with morphology consistent with parasitic forms were analyzed stereoscopically, microscopically, and by Scanning Electron Microscopy (SEM). Two genera of zoonotic parasites have been found: Anisakis sp. (Nematoda) and Trypanorhyncha gen. sp. (Cestoda). Of the 53 samples analyzed, 96% showed parasite contamination. The most affected organs were the intestine, muscle tissue, and stomach, with 596, 441, and 408 parasites, respectively. These results highlight the importance of sanitary inspection and emphasize the importance of immediate evisceration to avoid the migration of larvae from the viscera to the musculature.
S & atilde;o Jos & eacute; de Ribamar Bay, located in Maranh & atilde;o State, is one of the largest estuarine systems in Brazil. This study analyzes tidal and riverine regimes, as well as the spatial and seasonal distribution of physical water properties (salinity, temperature, and density) along the bay. Water-level observations were examined using harmonic analysis, and the annual modulation of tidal amplitude was obtained using the Hilbert transform. Historical discharge data from the Itapecur & uacute; and Munim rivers-the main tributaries supplying the bay-were analyzed to determine the climatological pattern of river flow. Salinity and temperature data were collected during four oceanographic surveys conducted along the bay: two during the wet season and two during the dry season. In each season, one survey was performed during spring tides and the other during neap tides. Water-column stratification was assessed based on these measurements. The tidal regime is purely semidiurnal and dominated by the M2 harmonic constituent. Tidal range varies from approximately 6 m during spring tides to 2.5 m during neap tides. Mean river discharge reaches approximately 1,000 m3 s-1 in the wet season and decreases to around 100 m3 s-1 in the dry season. Expressed as a flow ratio, river discharge represents only about 1% of the volume periodically exchanged during the wet season and about 0.1% during the dry season. Increased freshwater input in the wet season promotes a buoyancy flux that strengthens stratification. Consequently, the bay behaves as a well-mixed estuary during the dry season and as a strain-induced, periodically stratified estuary during the wet season.
Taxonomy provides the essential foundation for studying biodiversity, guiding ecological research and conservation efforts. However, the growing use of digital platforms for species identification introduces both opportunities and significant risks. Online crowdsourcing initiatives and citizen science projects engage the public but often rely on users with varied levels of training, potentially leading to misidentifications that can distort scientific data. A case study of Brazilian sea anemones revealed how unverified social media identifications overlooked a new endemic species, highlighting the potential conservation consequences of such errors. To balance public participation with scientific accuracy, this report recommends expert verification of crowdsourced data, the implementation of robust validation protocols, institutional accountability, transparent collaboration, and the strategic leveraging of emerging technologies such as Artificial Intelligence. While digital platforms democratize biodiversity science, maintaining rigorous taxonomic standards remains critical for effective conservation.
The incidental capture of sea turtles by fishing gear is a significant global threat to sea turtle populations. The increasing demand for seafood and seafood products raises the risk of sea turtle entanglement in fishing gear. Our study documented the encounter rate of sea turtles with fishing gear in Guyana, South America. Semi-structured interviews were conducted with fishers at key landing sites along the coast of Guyana. A total of 76 fishers participated in this study. Most fishers encountered sea turtles in their fishing gear at least once annually during fishing trips. Most turtles were captured in gillnet fisheries, and leatherbacks were the most caught species. Encounters were more frequent in August, aligning with the February-to-August nesting period. Most turtles were alive when encountered on the fishing nets, but the post-release mortality of the turtles is unknown. We also found that fishers knew that sea turtles are an endangered and protected species. However, they doubt that much can be done to prevent sea turtle bycatch without compromising their target catch. Our findings highlight the crucial role of collaboration between scientists, fishery managers, and fishers to understand sea turtle bycatch and develop and implement successful bycatch reduction strategies to conserve sea turtles.
Geotechnical and environmental studies widely use shallow geophysical imaging methods to indirectly acquire high-resolution subsurface data at a low cost for constructing three-dimensional models. Among these, seismic methods are especially valuable for investigating shallow submerged environments due to their capacity to produce detailed subsurface images. This study analyzes seismic facies patterns based on high-resolution shallow seismic profiles collected during a geotechnical investigation of the continental shelf offshore the Port of Suape, seeking to improve the understanding of the sedimentary and structural evolution of the transitional zone between the offshore and onshore regions of the Pernambuco Basin. The dataset comprises 14 multichannel 2D seismic sections, totaling 6.4 km of survey lines. Integrating sonographic data, borehole logs, sediment samples, and photographs enabled classifying three main types of seabed: (i) homogeneous mud seafloor; (ii) subaqueous dunes with gravel and sand; and (iii) irregular rocky substrate partially covered by sand. Interpretation of the seismic profiles identified five key reflections, including the present-day seabed and four major unconformities, And five seismic facies: (a) Facies I-unconsolidated sandy and muddy sediments (Quaternary); (b) Facies II-sandstones and shales of the Suape Formation (Lower-Middle Albian); (c) Facies III-basal deposits of the Cabo Formation (Barremian-Aptian); (d) Facies IV-carbonate mounds of the Estiva Formation (Cenomanian-Turonian); and (e) Facies V-crystalline basement (Ipojuca Magmatic Suite). Seismic and geotechnical data integrated allowed the reconstruction of stratigraphic layers associated with rift and post-rift phases of the basin. Additionally, a prominent positive seismic anomaly and normal faults trending NW-SE occurred at the basement top, suggesting extensional tectonic activity linked to the South Atlantic Rift.
Shallow-water coral reef ecosystems are positioned at the critical interface between terrestrial and marine environments, where ocean circulation patterns control the delivery and distribution of nutrients and land-derived substances. This study examines three-dimensional circulation patterns around Cura & ccedil;ao, a southern Caribbean reef island, using Lagrangian particle tracking analysis with the SCARIBOS hydrodynamic model for the period 2020-2024. We analyze two distinct surface flow regimes previously identified around the island: NW-flow periods dominated by the northwestward Caribbean Surface Current, and EDDY-flow periods characterized by cyclonic eddies or low-energy conditions. These regimes create contrasting patterns in horizontal surface circulation and vertical exchange, with significant differences in surface flow direction and enhanced upwelling during EDDY-flow conditions. However, analysis of offshore-to-nearshore connectivity using conditional pathways reveals that these large-scale surface regimes have no apparent influence on the delivery of deeper waters to nearshore coral reef areas. Spatial analysis reveals that volumetric transport decreases from east to west along the southern coastline. The West Point segment exhibits the lowest horizontal transport but the highest vertical exchange, receiving 48% of its volume transport from subsurface layers, contrasting with other segments where surface volume transport dominates (75-87%). These findings demonstrate that three-dimensional circulation patterns create spatially variable conditions for water renewal, nutrient delivery, and thermal regulation, improving our understanding of coral reef ecosystem dynamics and supporting reef management strategies.
Multi-decadal observations and reanalysis products of major ocean circulation systems reveal contrasting trends and complex inter-basin connectivity patterns that challenge traditional conceptualizations of global ocean circulation. Using non-parametric trend analysis, multi-method causality testing, and wavelet coherence techniques, we analyzed volume transport time series spanning 1984-2023 for the Indonesian Throughflow (ITF), Agulhas Current system, and Atlantic Meridional Overturning Circulation (AMOC). The ITF demonstrates statistically significant strengthening, with geostrophic (ITF-G) and salinity (ITF-S) components increasing by 0.79 and 0.28 Sv decade(-1), respectively (p<0.05). The temperature component (ITF-T) shows a positive but non-significant trend. Conversely, the AMOC at 26 degrees N from reanalysis exhibits robust weakening of -1.61 Sv decade(-1) (p<0.0001), while satellite-derived Agulhas transport proxies show no significant long-term trends despite substantial interannual variability. Causality analysis reveals four statistically significant pathways linking ITF components to Agulhas variability with lag times of 0-18 months, supported by consensus across maximum cross-correlation, convergent cross mapping, and transfer entropy methods. However, no direct causal connections emerge between either Indo-Pacific system and the AMOC at 26 degrees N, indicating regional forcing dominance over global-scale coupling on observable timescales. Wavelet coherence analysis identifies dominant annual-scale coupling (0.87-1.30 years) in ITF-Agulhas relationships, with enhanced coherence during major climate events including the 1997-98 El Nino. These findings suggest that contemporary ocean circulation responds primarily to regional forcing mechanisms - intensified Maritime Continent rainfall driving ITF strengthening and weakened North Atlantic convection controlling AMOC decline - rather than operating as a tightly coupled global conveyor belt. The identified statistical relationships provide critical observational constraints for ocean circulation models and highlight the need for sustained monitoring as anthropogenic forcing continues to reshape ocean gateway dynamics.
The accumulation and export of microplastics are associated with growing negative socio-environmental impacts, which are intensified in coastal and estuarine areas. The Santos Estuarine System is the most populous estuarine region and the largest seaport in Brazil, where the movement and accumulation of microplastics is an integrated effect of diverse hydrodynamic conditions. To identify the vulnerability of pollution by microplastics in extreme conditions of sea surface elevation, the coupling between Lagrangian and Eulerian modelling was employed, an approach that has become popular in the study of ocean movements. The trajectories of microplastics from potential sources were modelled using Opendrift, forced by currents from the Eulerian model Estuarine, Coastal and Ocean Model (ECOM), and waves from Wavewatch III. Particle concentrations and three-dimensional stochastic probability of contact with the continent were evaluated, demonstrating that, regardless of the sea surface elevation condition, mi-croplastics are more exported to the South Brazilian Bight than accumulated on the margins and/or bottom of the system. There is a greater accumulation of microplastics on the estuary margins during higher elevations of the sea surface, with spring tide promoting faster accumulation. Although the entire coastline of Santos and adjacent beaches are prone to the largest accumulations, portions further to the Northeast of the estuary have not shown the propensity to be contaminated with microplastics released into estuarine channels. The highest concentrations are actively drifting in the system's water column.
Sea anemones have a wide range of reproductive modes, which may contribute to their broad distribution. Understanding reproductive traits and patterns, such as seasonality, is important to elucidate the evolutionary processes that shaped the current distribution of this group. However, data on the reproductive cycles and gametogenesis of sea anemones remain fragmented. In this scope review, we compile existing knowledge, highlight topics requiring further investigation, identify patterns in the available data, and discuss potential methodological limitations in previous studies. We used the same search terms across three indexed scientific databases (Scopus, Web of Science, and ScienceDirect) and Google Scholar. The obtained articles were filtered for replicates and relevance to the topic (i.e., studies that included a description of the gametogenic process, with or without temporal sampling). To find articles not captured in the initial search, we conducted a forward and backward citation tracking. A total of 65 articles were included. According to our findings, research on gametogenesis and reproductive cycles of sea anemones began in 1964 and peaked in the late 1980s and early 1990s. Studies have investigated the reproductive cycles/gametogenesis of 43 sea anemone species across 14 families, with Actiniidae being the most studied. Most articles were conducted in temperate regions, analyzed oocytes and spermatic cysts together, employed microanatomical methods, did not use a classification system for spermatic cysts, and did not measure abiotic variables (e.g., salinity or temperature). The reproductive peak seems to be more closely associated with geographic location than with phylogenetic traits. Our findings provide an overview of the current state of research on sexual reproduction and gametogenesis studies in Actiniaria. We hope this review will serve as a guide for future studies to address gaps and improve existing methodological approaches in this field.
