Ocean and Coastal Research (OCR) é uma publicação com periodicidade em fluxo contínuo, no idioma inglês, com arbitragem por pares, destinada a divulgar resultados de pesquisa original nas diversas áreas da oceanografia, pesca, conservação marinha e ciências correlatas. Este título é uma continuação do Brazilian Journal of Oceanography (BJO), periódico publicado de forma ininterrupta desde 1950.
Instituto Oceanográfico - Universidade de São Paulo
Ocean and Coastal Research is an open-access journal available through SciELO (Scientific Electronic Library Online). Ocean and Coastal Research journal title abbreviation is Ocean Coast. Res. and should be used in footnotes, references, and bibliographic entries. All Ocean and Coastal Research scientific articles are freely available without charge to the user or institution. In accordance with the BOAI definition of open access, all contents are available to readers free of charge. Users may read, download, copy, and link to the full texts of the articles. They may be used for any lawful purpose without prior authorization from the publisher or the author, as long as proper credit is given to the original publication. All Ocean and Coastal Research published scientific articles receive an individual Digital Object Identifier (DOI) persistent digital document identification. All the content of the journal, except where otherwise noted, is licensed under a Creative Commons License type BY. Authors retain the copyright and full publishing rights without restrictions. More information on intellectual property can be found here and on Scielo's Open Acess Statement. Ocean and Coastal Research is listed in Publons and reviewers and editors can add their verified peer review and editing history to their Publons profile. Ocean and Coastal Research is indexed in the Directory of Open Access Journals (DOAJ) and complies with principles of transparency and best practice for scholarly publications. Ocean and Coastal Research is committed to the best standards in open-access publishing by adopting ethical and quality standards throughout the publishing process - from initial manuscript submission to the final article publication. This ensures authors that their work will have visibility, accessibility, reputation, usage, and impact in a sustainable model of scholarly publishing.
Baseline survey of microplastics in Phallusia nigra (Ascidiacea) in different sites along the Brazilian Coast, Central, and Southwest Atlantic
Microplastics (MPs) pose a growing threat to marine ecosystems, yet their accumulation in tropical ascidians remains understudied. This study investigated MPs in the digestive tract of Phallusia nigra from 15 sites along the Brazilian coast (75 individuals). Tissues were digested by alkaline solution, and MPs were quantified, measured, and characterized via microscopy and ATR-FTIR spectroscopy. MPs were detected in 64% of individuals (mean: 1.21 particles/individual), predominantly as fragments (63%) and fibers (37%), with an average of 0.77±0.81 MP/g. The most abundant polymers were polyethylene (PE), polypropylene (PP), and nylon (PA), consistent with global coastal pollution trends. The prevalence of PE, PP, and PA, polymers widely linked to fishing gear, packaging, and sewage, underscores the role of anthropogenic sources in tropical marine pollution. Besides these findings, this study emphasizes the need for standardized methodologies to assess MPs impacts on understudied filter-feeders and the urgency of extending monitoring efforts to tropical ecosystems.
Direitos autorais (c) 2026 https://creativecommons.org/licenses/by-nc-nd/4.0
From a boat and from the air: size and composition of humpback whale groups estimated by onboard observers and drone videos
This study compared the size and composition of humpback whale groups estimated from boat-based observations and drone video analysis during the 2022 and 2023 breeding seasons in Ilhéus, Brazil. Data from 43 groups showed that drone consistently recorded larger group sizes than boat-based observations, with a strong positive correlation between the two methods (r=0.94, p<0.001). Drone also enabled more accurate identification of group composition, detecting additional individuals and more complex group types - such as large competitive groups - than the boat-based method. A significant association between method and group composition was found (p<0.001), with drones identifying more groups composed of four or more adults or a mother-calf pair with several escorts. These findings underscore the advantages of drone-based surveys for improving assessments of group structure, contributing to more accurate data to monitor and conserve cetacean populations.
Feeding preference of the sea hares Aplysia brasiliana and A. juliana from Brazilian littoral: Different trophic specializations
Feeding preferences of benthic marine herbivores provides insight into their ecology, as well as their trophic relationships and potential impact on seaweeds. We present evidence of feeding preferences in Aplysia brasiliana and A. juliana sea hares, collected from two distinct locations along the Brazilian coast, based on laboratory experiments. Aplysia brasiliana from Forno Beach primarily consumed Laurencia dendroidea, a red seaweed known for its chemical defenses against herbivory, whereas A. juliana from Boa Viagem predominantly fed on Ulva fasciata, a palatable green seaweed. These results suggest that A. brasiliana has evolved dietary counteradaptations to chemically defended seaweeds, while A. juliana displays a more generalized preference for palatable seaweeds commonly consumed by several marine herbivores.
Productive and economic performance of an indoor intensive culture of Penaeus vannamei: comparing biofloc versus recirculating systems
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$ 7.00-8.00 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.
Paleoecological history of a Holocene coastal paleolagoon from southern Brazil based on palynomorph and diatom data
This study presents new data on the paleoenvironmental evolution of the southernmost portion of the Coastal Plain of Rio Grande do Sul (CPRS) to understand how regional and local paleovegetation responded to climatic and environmental changes during the Holocene. Palynomorphs and diatoms from a 44 cm-thick peat profile collected at Hermenegildo Beach (Santa Vitória do Palmar, RS) were analyzed. The top and base of the peat profile were radiocarbon-dated, enabling the construction of an age-depth model. The data indicate the presence of a paleolagoon between 4321 and 3903 calibrated years before present (cal yrs BP) (Late Holocene), with three phases: from 4321 to 4206 cal yrs BP, warm and humid conditions with high precipitation favored the development of forest vegetation and a local herbaceous marsh. The paleolagoon was characterized by brackish-to-freshwater conditions. From 4206 to 4018 cal yrs BP, regional and local vegetation declined, indicating drier climatic conditions. Changes in the paleolagoon’s salinity were evidenced by the presence of marine-brackish diatoms. From 4018 to 3903 cal yrs BP, the regional vegetation, composed of forest and grassland taxa, expanded again. However, indicators of the local herbaceous marsh decreased in expression. The paleolagoon returned to brackish-to-freshwater conditions. After 3903 cal yrs BP, the paleolagoon and its associated local vegetation were buried by eolian deposits, interrupting the vegetation succession process. The results highlight the importance of integrating palynological and diatom microfossil analyses to better understand the dynamics of coastal paleoenvironments and the impacts of climatic events during the Holocene.
The Linnean shortfall in the digital age: how unverified identifications obscure marine biodiversity
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.
Experimental assessment of microplastic selectivity in the brown mussel Perna perna (Linnaeus, 1758)
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.
Growth patterns and mortality rates of the short-necked clam Paratapes undulatus (Born, 1778) in Ba Lua Archipelago, An Giang Province, Southwestern Sea of Viet Nam
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 L∞ = 53.6 mm, K = 0.91 year-1, t₀ = -0.149, and tmax = 4.2 year and the growth performance index Φ′ = 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.
Microplastics invading corals: first scientific evidence from the Philippine Coral Triangle
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 μm) 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.
Otolith-fish length relationships in mesopelagic myctophids from the Southwestern Atlantic Ocean
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 worldʼs 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.
Assessing parasitic contamination in Katsuwonus pelamis
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.
Ocean-to-nearshore circulation patterns around Curaçao: a southern Caribbean reef island exposed to distinct flow regimes
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 Curaçao, 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.
Do human impacts and environmental factors shape intertidal meiobenthic communities across freshwater, estuarine, and oceanic beaches in Uruguay?
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 communities on Uruguayan sandy beaches respond to both natural environmental gradients and human disturbance, supporting the use of meiofauna as a sensitive tool for coastal ecosystem assessment.
Seasonal and synodical variability in the distribution of physical water properties in São José de Ribamar Bay, Brazil
São José de Ribamar Bay, located in Maranhão 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 Itapecurú 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.
A protocol for collecting coastal observations of oil spills from Instagram: case studies from the Brazilian coast
Oil spills cause extensive negative impacts on marine ecosystems. However, detecting and monitoring these incidents remains challenging, primarily due to the lack of real-time data for tracking and mapping oil along the coastlines. While some previous studies have utilized social media to extract georeferenced images of oil spills, there currently exists no standardized protocol for researchers to compile oil observations from these platforms. This study offers a comprehensive protocol for searching, filtering, and georeferencing oil spill observations based on Instagram. We analyzed social media posts regarding oil spills on the Brazilian coast that were shared during the 2019/2020 oil spill disaster (from August 2019 to August 2020) and included more recent observations from January 2022 to October 2023. A total of 312 oil spill observations were recorded in 170 localities for 2019/2020, and 162 observations were noted in 111 localities for 2022/2023. These records closely align themselves with previous observations in the literature. Our findings show that Instagram serves as a cost-effective and real-time tool for monitoring large-scale and sporadic oil spills. Despite some challenges associated with investigations using social media, our study highlights its potential to enhance the coastal surveillance of oil spills.
Direitos autorais (c) 2026 Lorena Silva Nascimento, Mauricio Almeida Noernberg https://creativecommons.org/licenses/by-nc-nd/4.0
Way beyond its primary goal: a decade of scientific contributions from the world’s largest systematic beach survey program
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.
Incidental capture of sea turtles in fishing gears along the Guyana coast
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.
Strengthening ITF and weakening AMOC: time series evidence of trends and causal pathways to Agulhas variability
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 26ºN 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 26ºN, 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 Niño. 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.
Atlantic Meridional Overturning circulation
Seismostratigraphy of the inner shelf adjacent to Suape Bay, Northeastern Brazil
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.
Direitos autorais (c) 2026 Carlos Eduardo G. S. de O. Fabin, Sharliane Dornelle d’Almeida Arruda, Gaby Carvalho Alves, Valdir do Amaral Vaz Manso, José Diniz Madruga Manso Filho, Narelle Maia de Almeida, Renê Jota Arruda de Macêdo https://creativecommons.org/licenses/by-nc-nd/4.0
Length-weight relationships and relative condition factor of some commercially important fishes and invertebrates in the southwestern sea of Vietnam
Length-weight relationships (LWRs) and relative condition factor (Kn) of some commercially-important fish and invertebrate species including Atule mate (Cuvier, 1833), Dendrophysa russelii (Cuvier, 1829); Encrasicholina heteroloba (Rüppell, 1837); Euthynnus affinis (Cantor, 1849); Mulloidichthys vanicolensis (Valenciennes, 1831); Nemipterus mesoprion (Bleeker, 1853); Pennahia anea (Bloch, 1793); Rastrelliger brachysoma (Bleeker, 1851); Sardinella gibbosa (Bleeker, 1849); Saurida elongata (Temminck & Schlegel, 1846); Saurida undosquamis (Richardson, 1848); Scolopsis taenioptera (Cuvier, 1830); Upeneus tragula (Richardson, 1846); Sepiella inermis (Van Hasselt, 1835); Parapenaeopsis maxillipedo (Alcock, 1905); Portunus pelagicus (Linnaeus, 1758) were determined using 12,727 specimens collected from two fisheries independent surveys and monthly port sampling between November 2022 to October 2023. The slope (b) values of the LWRs ranged from 2,613 for S. inermis to 3,528 for R. brachysoma. Eleven species exhibited positive allometric growth, three had negative allometric growth and two had isometric growth.
Direitos autorais (c) 2025 Vu Viet Ha, Tu Hoang Nhan https://creativecommons.org/licenses/by-nc-nd/4.0
Genotoxicity assessment in estuarine environments using oyster hemocytes: a comparative comet assay study
The comet assay with sentinel organisms has been employed to determine the genotoxicity of water samples for environmental risk or hazard assessment. Methodologies with diverse sensitivities have been proposed to elucidate the sources of genetic damage, thereby enhancing environmental assessment and informing decision-making processes. The conventional method and the modified conventional method with the DNA excision enzyme formamidopyrimidine-DNA glycosylase (FPG) were used to evaluate DNA damage in oyster (Crassostrea rhizophorae) hemocytes. The oysters were exposed for seven days to water samples from three estuarine regions with different degrees of impact on the Brazilian equatorial margin: (1) Carimã Island, which is distant from the main industrial activities of Maranhão Island (reference area), (2) Itaqui Port, and (3) Bacanga Lagoon. Genetic damage tests were performed in parallel with an early-stage assay using oyster embryos. The results revealed that the degree of genetic damage varied depending on the water sampling location and genetic damage method used. Regarding sampling sites, the frequency of anomalies in embryos/ larvae and genotoxic damage increased as follows: Carimã Island<Itaqui Port<Bacanga Lagoon. Regarding the method, the total genetic damage index was 58%, 69%, and 41% greater when the FPG comet assay was used than when the conventional comet assay was used for samples from Carimã Island, Itaqui Port, and Bacanga Lagoon, respectively. However, it was only 13% in samples of the positive control group (Carimã Island + H2 O2 ). Furthermore, a stronger correlation (R = 0.8) was observed between the frequency of anomalies in embryos/ larvae and the genotoxic damage measured via the FPG comet assay than via the conventional comet assay (R = 0.4). Therefore, the FPG comet assay was a more sensitive method, which enabled a better classification of environmental risks because of the teratogenic and genetic effects observed in oysters.
Direitos autorais (c) 2025 Clovis Lira da Rocha-Júnior, Luis Fernando Carvalho-Costa, Mateus Brandão Marques, Adalto Bianchini, Ricardo Luvizotto-Santos https://creativecommons.org/licenses/by-nc-nd/4.0
The history of ocean circulation models utilizing sea water potential density as a vertical coordinate is described. After a brief review of several models belonging to this class, emphasis in this article shifts to the ocean models MICOM and HYCOM developed by the authors and others at the University of Miami during the period 1980– 2010.
Direitos autorais (c) 2025 Rainer Bleck, Shan Sun https://creativecommons.org/licenses/by-nc-nd/4.0
Hydrodynamic modelling in the Amazonian Estuary: A flexible mesh approach
Several hydrodynamic models have been applied to the Amazonian Estuary, but its complex shape makes the grid definition difficult when a structured grid is used. This research aims to implement a hydrodynamic model for this estuary based on a flexible mesh grid system and then analyze the results. The methodology is based on Delft3D FM, and the model domain encompasses the low course of the Amazon, Tapajos, Xingu, Tocantins, and Para rivers, Guajara and Marajo bays, and Breves Strait, as well as the floodplain areas and the adjacent continental shelf. The model simulation performs well against the observed tidal water levels and instantaneous transport since Pearson’s correlation coefficient showed more significant values than 95% for both, and root mean square error (RMSE) showed smaller values than 5% for water levels and 15% for instantaneous transport. This also performs well in simulating scenarios representing different tide and instantaneous transport conditions.
Direitos autorais (c) 2025 Thais Borba, Dano Roelvink, Marcelo Rollnic https://creativecommons.org/licenses/by-nc-nd/4.0
Sexual reproductive cycle and gametogenesis in sea anemones (Cnidaria: Anthozoa): a scope review
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.
Direitos autorais (c) 2025 Rafael A. Brandão, Yago A. de Melo, Carlos D. Perez, Paula B. Gomes https://creativecommons.org/licenses/by-nc-nd/4.0
Estimating the length-weight relationship and relative condition factor of the Omani abalone (Haliotis mariae Wood, 1828)
This study examines the length-weight relationship (LWR), growth patterns, and relative condition factor (Kn) of the Omani abalone (Haliotis mariae), using data collected over 12 months from key fishing areas in Dhofar, Oman. The primary aim is to establish LWR equations and assess growth dynamics across size classes to enhance fishery management practices. The LWR equations derived were W = 0.000046 x L3.2417 for total weight and W = 0.000019 x L3.2764 for foot weight, both showing a high correlation between weight and shell length, indicating reliable predictive strength for estimating abalone size from weight. Growth analysis revealed isometric growth (in which body proportions remain constant with size) in smaller and larger abalones, whereas medium-sized individuals showed positive allometric growth (in which weight increases faster than length), likely reflecting changes associated with maturation stages. Kn values ranged from 1.003 to 1.011 throughout the study period and were consistently above or near one across the locations, highlighting stable condition and general health, with minor variations among regions. The findings provide a basis for estimating harvestable biomass and applying size-based monitoring in Omani abalone fisheries. Implementing LWR-based methods can strengthen regulatory enforcement and help sustain abalone populations, with broader implications for ecological and socioeconomic resilience. Future studies may build upon such findings by incorporating environmental parameters to further explore their influence on growth dynamics and health status.
Direitos autorais (c) 2025 Salim Al-Ghassani, Salem Kahoom https://creativecommons.org/licenses/by-nc-nd/4.0
Habitat risk assessment of fragmented mangal ecosystem using InVEST models: a case study in San Fernando City, La Union, Philippines
La Union is renowned as one of the major tourist destinations in the Philippines, primarily the City of San Fernando, which houses a vast stretch of pristine coastal and wetland ecosystem that includes tropical beach and lush mangrove forests. However, despite the beneficial services mangal ecosystem provides for the coastal communities of San Fernando City, La Union, they remain vulnerable to risk caused by anthropogenic stressors in exchange for growing economic development. To ascertain this observation in the region, it is urgent that an evidence-based decision framework for the habitat risk of the remaining patches of the mangal ecosystem in smaller districts (barangays) of the whole municipality be established. Hence, this study was conceived by employing a mangal assessment based on exposure and consequence scores from anthropogenic stressors using the InVEST Habitat Risk Assessment model. Key findings showed the following: (1) the business-as-usual scenario configures a high cumulative risk due to road structures and other concrete pavements, (2) in a controlled and protected scenario, the mangal ecosystem will likely shift from medium to low risk, and (3) a reduction in cumulative risk for the mangal ecosystem is expected under public-private partnership intervention scenario. Nevertheless, the remaining sites in which the mangal ecosystem thrives must be targeted for intense active intervention and management from private and public stakeholders. This study serves as the basis for data-driven policies, highlighting the importance of adequately implementing management strategies to protect a critical wetland habitat.
Direitos autorais (c) 2025 Cheska Jan Balasabas-Fresco, Melissa Caceres-Baysic, Mark JohnFer Alonzo-Magalona, Katherine Iona Muller, Nikki Heherson A. Dagamac, James Eduard Limbo-Dizon https://creativecommons.org/licenses/by-nc-nd/4.0
Economic feasibility of small-scale aquaculture of scallop (Nodipecten nodosus) and cobia (Rachycentron canadum) in a multi-trophic system on the southeastern Atlantic coast
This study evaluated the economic feasibility of scallop monoculture (Nodipecten nodosus) in six 100-meter longlines, monoculture of cobia (Rachycentron canadum) in twelve 565.5 m3 net cages, and the integrated multitrophic aquaculture system (IMTA) with both species, in four longlines and six net cages of the same dimensions, in an area of 5,000 m2 , on the southeastern coast of Brazil. This study aimed to determine whether this approach could provide greater profitability and resilience than traditional monocultures. Investments, operating costs, and profitability were estimated for the three production systems according to the variation in survival, productivity, and market prices. The financial indicators showed positive values for the three systems evaluated. There was a reduction of US$ 1.88 per dozen scallops from scallop monoculture to IMTA and US$ 0.22 per kg of cobia from cobia monoculture to IMTA. However, comparatively, scallop monoculture had the worst results. For this system, although the IRR (35.03%) and MIRR (19.37%) are above the MRA (12%), the NPV, ANPV, and PP (US$ 69,785.07, US$ 12,350.85 and 3.71 years, respectively), had lower economic attractiveness when compared to the other two systems evaluated. Between cobia monoculture and IMTA, there is a certain proximity of results. The IMTA system showed a slight advantage in terms of the highest market prices. The diversification of production is an interesting option even with the greater associated investment, which can favor economic returns and mitigate the risks of small-scale systems dedicated to monocultures.
Direitos autorais (c) 2025 Matheus Pires Sergio, Rodrigo Francisco Prieto, Leonardo Castilho-Barros, Marcelo Barbosa Henriques https://creativecommons.org/licenses/by-nc-nd/4.0
Phosphorus chemical speciation in surface sediments from Cananéia – a non-impacted estuary
Phosphorus (P) is found in estuarine sediments, which belong to the biogeochemical cycle of this element in aquatic environments. This study examines the distribution of P in different chemical speciations in surface sediments at 14 stations in the southern region of the Cananéia-Iguape Estuarine-Lagoon Complex. P chemical fractions were determined using a sequential extraction method of fractional extraction that measures five P forms: (i) exchangeable P (Pexch), loosely adsorbed or exchangeable; (ii) P-Fe (P-Fe), P-bound Fe oxyhydroxides; (iii) authigenic P (P-CFAP), including carbonate fluorapatite, biogenic apatite (fish debris), and P-bound calcium carbonate; (iv) detrital P (P-FAP), igneous or metamorphic apatites; (v) organic P (Porg); and (vi) total P (Ptotal). The P fractions associated with the sedimentary properties of grain size and organic content can be used as a proxy for understanding environmental conditions. The average percentage of each P fraction of the surface sediments in this region follows the sequence: P-Fe (38%) > Porg (32%) > Pexch (14%) > P-FAP (9%) > P-CFAP (7%). In all stations, P-Fe and Porg were the main fractions of P in the sediments. CaCO3 accounted for less than 30% of it, essentially indicating lithoclastic characteristics, whereas organic carbon (Corg) showed values below 2%. Finally, Ptotal showed concentrations that are consistent with an unpolluted environment, with values below 16 µmol g-1.
Direitos autorais (c) 2025 Gláucia Bueno Benedetti Berbel, Vitor Gonsalez Chiozzini, Elisabete de Santis Braga https://creativecommons.org/licenses/by-nc-nd/4.0
Assessing chlorophyll-a retrieval of Sentinel-3 OLCI, VIIRS, MODIS and OC-CCI in Monterey Bay (California, USA)
Advances in high-resolution satellite sensors and merged multi-sensor ocean colour products have improved the detection of submesoscale features and enhanced the continuity of ocean surface measurements. This has enabled more detailed observations of chlorophyll-a (chl-a) growth rates, biomass and biogeochemical fluxes. Chl-a, a photosynthetic pigment in marine autotrophs, is used as a proxy for phytoplankton biomass and primary productivity. The accurate estimation of surface chl-a via remote sensing is key to improving coastal ocean process modelling. We compared chl-a products from sensors of multiple spatial resolutions, including Sentinel-3 Ocean and Land Colour Imager (OLCI), the Moderate Resolution Imaging Spectroradiometer (Aqua) (MODIS Aqua), the Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP and the Ocean Colour Climate Change Initiative (OC-CCI) V6 product to two in situ datasets (M1 and C1) in Monterey Bay, California, USA. Sentinel-3 consistently performed well under the Inverse Modelling Technique - Neural Network chl-a algorithm, performing slightly better at station M1 (R2 M1 = 0.85, R2 C1 = 0.80). The Ocean Colour for MERIS algorithm performed better at offshore station M1 (R2 M1 = 0.87) and yielded no matchups at C1. MODIS Aqua and VIIRS performed poorly (R2 M1,MODIS = 0.32, R2 M1,VIIRS = 0.02, R2 C1,MODIS = 0.08, R2 C1,VIIRS = 0.25), likely inhibited by calibration to global as opposed to regionally adapted datasets. OC-CCI, though blended for greater continuity, produced fewer matchups at a higher accuracy (R2 M1, OC-CCI = 0.66, R2 C1, OC-CCI = 0.63) than MODIS Aqua or VIIRS alone, but still less so than Sentinel-3 OLCI. All sensors either over- or under-estimated chl-a at all concentrations, apart from OC-CCI, likely due to the complex coastal optical properties of the area. Our results highlight the need for regional algorithm development and show the potential effectiveness of Sentinel-3 and OC-CCI products for future submesoscale process studies.
Direitos autorais (c) 2025 Elliot Styles, Lael Wakamatsu, Andrew M. Fischer https://creativecommons.org/licenses/by-nc-nd/4.0
Managing the risk of marine bioinvasion via biofouling: trends in methods of assessment, policy, and legislation
Maritime shipping has been recognized as the main pathway of species transference throughout the world. Ballast water or fouling on vessels have become the main vectors of aquatic species transportation between coastal marine ecosystems, which can lead to significant social, economic, and ecological negative impacts. Approximately 55% of non-indigenous marine species can be associated with vessel biofouling. However, acting to prevent, detect, manage, and control bioinvasion via biofouling is relatively recent. To improve nonindigenous marine species management, several risk assessment frameworks have been proposed. This research undertook a systematic bibliographic review to investigate whether and how risk assessment has been used to manage marine bioinvasion via biofouling. We analyzed 410 scientific studies published until December 31, 2023, via the Scopus database, filtering them by keywords, title, and abstract. This study describes the parameters and methodologies to assess bioinvasion risks. Furthermore, it discusses the incorporation of risk assessments into global, regional, and country-level public policies, the latter based on countries that publish the most on the topic. This research highlights the scarcity of mandatory measures to manage biofouling, as well as the urgent need to standardize risk assessment methodologies and to incorporate the effects of climate change into these assessments. The development of advanced data analysis tools and a unified strategy to effectively address the complex challenge of marine bioinvasions is also suggested.
Direitos autorais (c) 2025 Fabio C. Xavier, Fernanda C. B. Araujo, Daniela Batista, Luciana V. R. de Messano, Damián Mizrah, Leandro Calado, Sávio Calazans, Beatriz Vallim, Ricardo Coutinho https://creativecommons.org/licenses/by-nc-nd/4.0