Resumo em Inglês:

Abstract Formed during marine regression periods, shelf valleys (SVs) are preterit river flows on the exposed continental shelf. This study investigates the influence of tectonic activity on forming these important morphological features. This research combines bathymetric, magnetometry, and seismic data to analyze the role of tectonic events in SV genesis and positioning. The bathymetric dataset provides information on SV locations and geometries along the continental shelf, whereas the 2D seismic sections illustrate that SVs formed above post-rift faults that reached Quaternary deposits. Aeromagnetic data indicates that the shallow and deep structures of the basement and sedimentary column-controlled SV locations and evolution. The multi-data integration demonstrates a strong correlation between neotectonic structures and SV location and geometries from the inner shelf (−25 m) to the shelf break (−55 m). The analysis of the 2D seismic data indicated that high-angle faults, formed under a strike-slip tectonic regime, primarily affected the Middle Miocene deposits beneath the shelf valleys. The formation of “negative flower pattern structures” was identified as a primary structural mechanism that contributed to SV formation. Reactivation events that occurred from the Late Cretaceous onwards, gave rise to these faults, which control SV formation and the capture of preterit drainage on the exposed continental shelf. The SV geometries display straight patterns and abrupt changes in direction (90°) due to the interplay of the NE-SW and NW-SE aligned faults. The results reinforce the importance of considering tectonic activity in the formation and evolution of shelf valleys.

Resumo em Inglês:

Abstract “For more than two decades, the Philippine government has protected the giant clams (Bivalvia: Cardiidae: Tridacninae) from exploitation and trade. However, there still is lack of information on the impact of these protective measures in conserving the species richness and density, especially in Palawan, the country’s last stronghold of these reef-associated bivalves. Hence, to assess the species richness and density of giant clams in Palawan, we conducted 57 photo-transect surveys in six sites covering 12,325 m 2. Out of these transect, 15 measured 5 × 25 m and the rest measured 5 × 50 m. For historical trends in the population of giant clams in Palawan, we used six published papers obtained from online platforms, 13 reports, and five undergraduate theses archived in local libraries. Information derived from recent field surveys indicated high variations in species richness (2 to 5 species) and densities (0.1 to > 3.6 ind.100 m -2). Historical data starting from 1984, including recent fieldwork, indicated very low densities and a declining trend. The current status suggests that giant clam populations’ viability and the reefs’ health are threatened. Effective mechanisms are needed to safeguard and enhance the remaining giant clam populations.”

Resumo em Inglês:

Abstract This study aimed to investigate the biogenic composition of calcium carbonate (CaCO 3) in pelagic sediments in the Santos Basin over the past 140,000 years. The content and composition of CaCO 3 in different sediment fractions were evaluated, including the bulk sample, coarse fraction (foraminifera), medium fraction (juvenile foraminifera and fragments), and fine fraction (nannofossils), to determine the contribution of each fraction to the carbonated sediment composition. We found that variations in CaCO 3 levels were closely linked to glacial and interglacial periods, with higher values during interglacial periods and lower values during glacial periods. The main factor controlling the variation in CaCO 3 was dissolution, which was mainly linked to the influx of more corrosive southern water masses. Fluctuations in CaCO 3 levels were influenced by variations in productivity and dilution caused by terrigenous sediments. Nevertheless, it is noteworthy that both processes held a relatively minor impact compared to dissolution. Productivity primarily contributed to increased dissolution rates. During periods of low sea levels, dilution by terrigenous sediments became significant (similarly, the influence of the La Plata River plume was notable). However, due to the limited presence of riverine supply in the study area, which contributes directly to major dilution influences, fluctuations in terrigenous materials were considered of lesser magnitude than those caused by dissolution. The nannofossils were found to be the largest contributor to the total CaCO 3 composition, as they were the fraction least affected by the dissolution process. Overall, our results provide insights into the factors influencing CaCO 3 accumulation in marine sediments and can be used as a tool to determine changes between climatic cycles over time.

Resumo em Inglês:

ABSTRACT Several studies have reported on the presence of litter on beaches and in the oceans, but this represents the smallest part of the litter that ends up in the sea. Little is known about the litter that settles on the ocean floor, especially near coastal regions. Thus, this study quantified, classified and determined possible sources of subtidal benthic marine litter input off the coast of Rio de Janeiro, Brazil. Different sites were selected in Guanabara Bay, an area with the greatest industrial and population concentration in the state of Rio de Janeiro, and on the coasts of Costa do Sol and Costa Verde, where tourism represents the main economic activity. Material was collected by scuba diving at depths of between 5 and 15 meters at 31 sites distributed among the study areas. A total of 1, 209 items was found, with Guanabara Bay having the highest average concentration (92.40 items/km2), followed by Costa do Sol and Costa Verde (14.15 items/km2 and 9.91 items/km2, respectively). Plastic materials are the most representative solid waste (55.08%), followed by metals (14.97%) and fishing gear (12.48%). Results indicated that local activities affected the composition of the marine litter on Costa do Sol and Costa Verde, whereas in Guanabara Bay, anthropogenic material carried by rivers influenced the marine litter composition at certain locations in addition to local activities. Environmental education actions associated with tourism and fishing activities and better waste management are necessary to minimize the presence of litter in subtidal benthic environments.

Resumo em Inglês:

ABSTRACT Seaweed blooms pose a compelling governance challenge caused by the new environments of the Anthropocene. Along the Quintana Roo coastline, nestled in the heart of the Caribbean, the onset of extensive Sargassum infestations began in late 2014, posing a formidable environmental management dilemma for state and federal authorities. This study describes the institutional responses elicited by the Sargassum influx on Mexico’s Caribbean shoreline, particularly focusing on Cancún and the Riviera Maya. It proposes ecological reflexivity as a promising governance principle for institutions faced with increasingly complex and unforeseeable circumstances, such as the massive arrivals of Sargassum. Based on a comprehensive analysis of national press reports, active participation in forums and seminars, and in-depth interviews, our research identifies three distinct governance phases. We explore these phases considering the concept of ecological reflexivity. Our findings make a strong case for acknowledging institutional errors and shortcomings as an indispensable aspect of formulating effective strategies to combat unexpected and unfamiliar phenomena such as seaweed blooms. Moreover, governance strategies for dealing with Sargassum in Quintana Roo should not only consider responding to human interests and sustaining the tourist industry. Instead, they should encompass an approach that considers the interplay between human and non-human components within the socio-ecological system.

Resumo em Inglês:

ABSTRACT Along the coast of the state of Pernambuco, NE Brazil, the presence of coastal outcrops aligned with the shoreline and distributed above and below the mean sea level is remarkable. These outcrops were sampled, and petrological, isotopic, and geochronological analyses were integrated to investigate the local effects of the Holocene sea-level fluctuations. The results indicate that the rocks are recent (< 8ka), formed by cementation of beach sands (magnesian calcite cement, predominance of quartz and presence of marine bioclasts, signs of compaction, fractures, and dissolution), in a tropical climate and warm waters, which allows to classify them as typical examples of beachrocks. The carbonate cement consisted of Mg-rich calcite with values ranging from −1.1‰ to 3.5‰ for δ13C and from −0.9‰ to 0.5‰ for δ18OVPDB. These isotopic values are typical of marine carbonate cemented deposits in shallow marine environments under freshwater influence (meteoric vadose environment). In these conditions, the cementing processes occurred in the intertidal zones, which reinforce the use of these data as indicators of ancient sea levels. The sea level fluctuations could be divided, in chronological order, into three different phases, starting with a rapid sea level rise followed by a relative stabilization at a maximum level and, finally, a decreasing phase. Recent sea level fluctuations in Pernambuco are represented by beachrocks with ages between 8 ka and 800 years and a maximum level of 2 to 3 meters above the present mean level. In scenarios of a near future with a general global sea level rise pattern, significant local geomorphological changes may occur, which means a great future challenge to society.

Resumo em Inglês:

ABSTRACT The South Pacific hake, Merluccius gayi, is an ecologically and economically important species in Ecuador. However, studies regarding its feeding habits remain scarce. This study aimed to characterize the food and feeding habits of M. gayi in the Ecuadorian Pacific Ocean by sex, sexual maturity stages, size classes, and years. Hakes obtained (n = 2993) from industrial fishing (captured with seine nets) were analyzed from September 2013 to December 2014. Their diet was composed of 27 prey species. The most important prey was the euphausiid Nyctiphanes simplex (52%) and the same hake species (M. gayi; 31%) according to the prey-specific index of relative importance (%PSIRI), making this species a cannibal predator. Results show no significant dietary differences between female and male hakes or immature and mature males, but found differences between immature and mature females and individuals from four size classes and hake between 2013 and 2014. According to Levin’s Index, the species showed a low trophic niche breadth (Bi = 0.03), making it a selective specialist mesopredator with high specialization. The trophic overlap analysis based on Jaccard’s index by sex was low (J = 0.23) for indetermined individuals, moderate (J = 0.59) for males and females, and high (J = 0.78) for immature females and males; moderate values were noted for size classes (J = 0.42-0.63) and low for years (J = 0.31). Based on the Cortés index, the trophic level totaled (TLk = 3.22), indicating that this species is a primary and secondary carnivore mesopredator. This information supports the understanding of the relations between predators and prey and the flow of nutrients and energy in marine ecosystems, which serve as a base for ecosystemic fishing management.

Resumo em Inglês:

ABSTRACT Holopelagic Sargassum has been causing massive strandings on tropical Atlantic Ocean shorelines. Describing the microbiome associated with Sargassum and how it changes after stranding is important to identify potential microbial introductions to coastal environments, as well as sources of potential biotechnological resources. In this study, stranding simulation exploratory experiments were conducted for S. fluitans III and S. natans VIII on shipboard with minimum external influence. Samples for microbiome identification were collected just after removing healthy Sargassum from the seawater (0 hr) and after 24 and 48 hrs of stranding simulation under environmental conditions. The bacterial community was identified by sequencing 16S rRNA gene V3-V4 hypervariable regions, generating a total of 1,565 Amplicon Sequence Variants (ASVs). Of those, 588 were shared between Sargassum species and only 25 persisted throughout the stranding. Stranding also changed the dominance of Microtrichales and Rhodobacterales orders at 0 hr to Alteromonadales and Vibrionales after 24 hrs of exposure, the latter representing up to 92% of the relative abundance in the bacterial community. The increase in Vibrionales reinforces the need to monitor stranding sites for any potential pathogenic bacteria. At the functional level, phototrophs were the main group at 0 hr, shifting to chemoheterotrophs and fermentation within the first 24 hrs of Sargassum exposure to air conditions. The fermentative groups native to Sargassum use stranded biomass as substrate for growth, and therefore constitute the bacteria with higher biotechnological potential.

Resumo em Inglês:

ABSTRACT The emissions of CH4 and CO2, the primary greenhouse gases, have a significant impact on radiative forcing. This study investigated these gases along the Cananéia-Iguape estuarine system on the southern coast of the State of São Paulo, Brazil, which is a mangrove region characterized by low anthropogenic impact and a sparse population. As such, this area provides an ideal location for identifying natural emissions and background concentrations. The data for this study were collected using a portable gas analyzer (LGR-ICOSTM GLA131), known for its high sensitivity and precision in detecting gases, mounted on a research boat. The results obtained were promising for both gases. A small variability in CH4 concentrations was observed along the route, ranging from 1.84 ppm to 1.95 ppm, while CO2, showed greater variation in values obtained during routes, ranging from approximately 411 ppm to 575 ppm. This study underscores the importance of investigating areas with minimal environmental impact. Together with future analyses, this research should help improve Greenhouse Gas (GHG) inventories in Brazil by providing valuable baseline data for comparisons with more impacted areas.

Resumo em Inglês:

ABSTRACT Bycatch species are as important as target species in the challenge of comprehensive fishery management. This is especially the case for vulnerable species such as elasmobranchs in offshore areas of the Colombian Pacific Ocean (CPO), for which information is scarce and long-term databases are used. Therefore, this study aimed to characterize the bycatch in tuna purse-seine fishery with an elasmobranch species approach using fishery data from 2000 to 2019. A total of 59 bycatch species were identified, including 27 bony fishes, 22 elasmobranchs, two mollusks, four sea turtles, and four dolphins. The total bycatch percentage was 20.8%, with elasmobranchs accounting for less than 5%. Fish aggregating devices (FADs) and class 6 vessels recorded the highest percentage of bycatch. Bony fish bycatch was mainly obtained from the border of Ecuador until 4° N across the CPO. Elasmobranchs were captured throughout the CPO, showing differences by vessel class and fishing method. The silky shark Carcharhinus falciformis was the most caught species. Elasmobranch spatial abundance and capture hotspots showed the highest values towards the northern coast, in offshore areas of Gorgona Island, southwards in offshore areas, and around Malpelo Island. FADs captured the highest number of bycatch species compared with other fishing methods, such as Tuna Associated with Dolphins (DEL), Natural Floating Objects (NAT), and Tuna not Associated (NoAs). Management recommendations for bycatch species in this fishery are provided in the CPO.

Resumo em Inglês:

Abstract Ecoacoustic indices may become an important tool to monitor marine ecosystems because they take passive and non-invasive measurements over wide spatial and temporal ranges. However, the performance and limitations of marine ecoacoustic indices are yet to be fully understood. This study evaluated the Acoustic Complexity Index (ACI), Acoustic Diversity Index (ADI), Bioacoustic Index (H), and Normalized Difference Sound Index (NDSI) in a marine protected area (MPA) named Resex mar Arraial do Cabo in a coastal upwelling in Rio de Janeiro, Brazil. All considered variables, such as water temperature, wind direction, solar radiation, and vessel traffic were monitored from September to December 2018. Principal component analysis showed that the ACI index was negatively correlated with the number of vessels, whereas the ADI and H indices were correlated with water temperature. After categorizing specific moments, the ACI configured the best index for differentiating specific times of day, whereas the ADI was ideal for distinguishing between moments with and without vessel presence. Thus, the ACI and ADI showed the best performance overall. This study identified the main variables influencing the soundscape of a productive upwelling region and intensely used MPA. Furthermore, this research has laid the foundation for further exploration and the development of a robust, non-invasive tool for monitoring marine environments.

Resumo em Inglês:

Abstract Among the various forms of pollution, anthropogenic debris has been widely documented to cause entanglement and premature death of sea turtles, in addition to being ingested by these animals. One of the most affected species is the green turtle, which is commonly found along the south-central coast of Rio de Janeiro (RJ), an area characterized by high human population density. This study aimed to assess the impact of anthropogenic debris on green turtles by analyzing the gastrointestinal tracts of 66 individuals stranded along the south-central coast of RJ, as documented by the Santos Basin Beach Monitoring Project. Pieces of debris (1,683 in total) were found in 69.7% of the individuals analyzed, with the highest concentration observed in the large intestine. The most common types of debris were flexible plastic waste (50.5%; 850 items) and amber/brown debris (36.5%; 614 items) within the size range of 0.5 mm to 2.5 cm (41.2%; 693 items). No significant differences in debris composition were observed between turtles encountered inside and outside the bays. The substantial number

Resumo em Inglês:

Abstract The storm risks in coastal regions have drawn attention worldwide in recent decades. Understanding the characteristics and behavior of these events and their potential damage to coasts has become essential for decision-making and coastal management. This study aimed to identify and examine the climatology of coastal storms on the central coast of the state of Rio de Janeiro, proposing a classification and a coastal impact evaluation that applies Dolan and Davis’ ( 1992 ) storm index. For this, 34 years of NOAA/NCEP/NCAR hindcast wave database were used (1979 - 2013). Secondarily, this study aimed to compare wave data at two locations (the south-orientated west and the east-northeast-orientated east coasts) to verify the influence of coastal orientation against storm events. This research found 231 storm events on the west coast and 44 on the east coast. While mean durations resembled each other (at around 27 hours), the east coast had a 9% lower mean storm wave height. The storm peak direction from the south predominated on the west coast (52%), whereas a south-southeast direction dominated the east coast (50%). Storm classification showed 3.4 and 9% of storms considered Extreme in the west and east, respectively. Extreme storms include those in September 1983, May 1997, May 2001, and April 2010. Coastal storms on the west and east represented 2.39 and 0.57% of all cyclones identified in the southwestern Atlantic. In shallow waters, the highest amount of energy dissipation occurred on the east coast, which is sheltered from storms from the south-southwest but is exposed to those from the south-southeast. Extreme and Severe events greatly impacted the coast, including beach and dune erosion, overwash, and property damage. However, even coastal storms considered Weak caused considerable coastal damage.

Resumo em Inglês:

Abstract A 117-year series of hourly-observed heights in the Río de la Plata estuary allows studying the recorded changes in positive storm surge (PSS) events spanning from 1905 to 2021, and calculate the annual mean river level (AMRL) trend. The analysis of PSS focuses on the trend of the annual number of events, the annual mean events duration, and the annual maximum PSS height. Seasonal analyses of these variables can also be conducted. This study aimed to ascertain any correlation between the rising AMRL and the evolution of PSS. Since AMRL increase is related to the effects of global warming, the observation series is divided into two periods based on the behavior of the curve of greenhouse gas emissions into the atmosphere. One period covers 1905 to 1962 and is characterized by a less pronounced curve slope, while the other period, 1965 to 2021, exhibits a drastically steeper curve slope. Moreover, two sets of data were obtained to calculate the PSS in two different scenarios for both periods: a hypothetical one, with no trend in AMRL, and a realistic one, maintaining the observed AMRL trend. The results show the acceleration trend of two of the analyzed variables, namely the annual number of events and the average duration of events, when transitioning from one period to the other (following the behavior observed in AMRL). However, the increase in AMRL could not be the only explanation of these accelerations. On the one hand, although the accelerations decrease when the hypothetical scenario is considered, they do not totally disappear. Moreover, the annual average duration of the events increases follows the realistic scenario when removing AMRL trend. On the other hand, the maximum height of PSS shows no trend in either period and remains unaffected comparing the two scenarios.

Resumo em Inglês:

Abstract Coastal habitats are important feeding grounds for migratory shorebirds, which turns the coast of Piauí State into an important region for birds’ migration cycle. This study aimed to identify migratory shorebirds, analyze their patterns of habitat preference on coastal Piauí State, Brazil, and identify classes of invertebrates found in foraging sites. In total, 23,829 records of migratory shorebirds belonging to 15 species were found at feeding sites, presenting significant segregation between different foraging substrates (F1,23 = 8.41; p = 0.001). Limnodromus griseus (56.5±98.42; p > 0.001), Numenius hudsonicus (35.96±37.37; p > 0.001), and Calidris canutus (34.4±80.84; p < 0. 001) were the species accounting for the highest densities in muddy substrate. Calidris pusilla (77.37±178.02; p > 0.001), Charadrius semipalmatus (66±142.17: p > 0.001), and Calidris alba (56.5±181.24; p > 0.001) were the most significant species in sandy-muddy substrate. Birds’ lowest density was observed in sandy habitat, but C. alba (22.41±40.9) recorded the highest density in this substrate. Overall, most shorebirds (92.8 %) preferred foraging substrates presenting higher concentration of fine particles (silt, clay, and fine sand). Invertebrates belonging to classes Polychaeta, Gastropoda, Bivalvia, and Malacostraca prevailed in these sites. Therefore, substrate type and prey composition are factors influencing the density of migratory shorebirds in foraging sites. In addition, this region witnesses the occurrence of endangered species, and it reinforces the importance of these feeding sites for them during their migration to Brazil’s coastal region.

Resumo em Inglês:

Abstract The Fundão dam failure in the Rio Doce basin in 2015 triggered a significant socioecological regime shift. In this study, changes and strategies employed by small-scale fisheries (SSFs) in the wake of dam failure were analyzed. From 2021 to 2022, 441 semi-structured interviews were conducted with fishers in Espírito Santo municipalities, using the snowball method to sample 20% of total fishers. The interviews focused on socioeconomic aspects and post-disaster changes. Responses were statistically analyzed according to data type (chi-square test, ANOVA, or Kruskal–Wallis’s test). Overall, 96.35% of surveyed participants were impacted by the dam failure. The strategies adopted after the disaster characterized three groups: the first abandoned the fishery, the second made adaptations in their fisheries, and the third did not make any changes. In this context, we highlighted two aspects for study: (1) understanding the characteristics of the most affected groups and (2) understanding the main adaptations found. The first aspect mainly involved those farther from the coastal zone, including a higher proportion of women and older and more experienced individuals who currently have a lower mean income and greater economic dependence on monetary indemnities. The second aspect involved those who managed to make adaptations, largely aimed at maintaining fishing activities, often by changing the target species and/or fishing area. All groups identified environmental contamination as the main current challenge. This study contributes to the deepening of knowledge about local impacts and recovery strategies following human-made disasters. Moreover, understanding the experiences of groups affected to varying degrees, each with distinct implications and structural differences, can facilitate the development of collective strategies for more effective coping with the challenges faced by SSFs. This case presents potential for improvement by adopting more participatory frameworks aimed at implementing mitigation and recovery measures.

Resumo em Inglês:

Abstract Marine litter has become a significant environmental issue with increasing evidence of its impact on oceans and coastal areas across the planet. This study focuses on the distribution and composition of marine litter in three regions of Iceland - Southwest, Westfjords and Northeast - and on marine litter as a vector for fouling species. The results of this study show that plastic litter was the most abundant type of both fouled and non-fouled marine litter. The beach surveys showed that land-based sources, such as mismanaged waste, were the primary contributors to beach pollution. In contrast, most fouled litter, such as fishing gear, originated from sea-based sources. Over 79,000 individuals belonging to at least 92 species were found on fouled litter at the eight surveyed sites. The Southwest had the highest abundance and the most fouled litter collected. However, the Westfjords had the highest diversity and species evenness. The phyla of the fouling species found included Annelida, Arthropoda, Bryozoa, Chordata, Cnidaria and Mollusca. Cnidaria exhibited the highest fouling percentage in the Southwest and Northeast regions, whereas Annelida had the highest fouling percentage in the Westfjords. Statistically significant relationships were found between species richness and region, abundance and region, material type, and surface rugosity and thickness. These findings highlight how fouling species can be transported via marine litter and underscore the need to continue monitoring marine litter in Iceland and implement management strategies to reduce its impact on the marine and coastal environment.

Resumo em Inglês:

Abstract During an expedition in January 2019, nanoplastics were sampled at a depth of −5,170 m over Cape Basin, in the South Atlantic Ocean. Using photo-induced force microscopy, it was suggested that these were polyethylene terephthalate (PET-like) particles with various sizes down to 100 nm, at different stages of degradation. By using a state-of-the-art Lagrangian 3D model, which includes fragmentation, we backtracked virtual particles to map the origin of the PET nanoplastics sampled at this location. Fragmentation processes are crucial to understanding the origin of nanoplastics (and microplastics) because they allow for detecting when and where particles become so small that they transition to a colloidal state, in which the buoyant force becomes negligible. We found that it is very unlikely that the nanoplastic particles entered the ocean as nanoplastics and then drifted to the sampling location. We also found that the fragmentation scheme, particularly the fragmentation timescale prescribed to the modeled particles, affects how they drift in the ocean by the velocity with which they sink. This study contributes to understanding the fate and sources of nanoplastics in the deep ocean and the development of 3D backtracking simulations for source attribution of ocean plastic.

Resumo em Inglês:

Abstract Functional diversity (FD) is one of the aspects of biodiversity that can best represent eventual changes in the environment. Marine Protected Areas (MPAs) can be used to minimize the potential impacts of fishing on fish stocks. The objective of this study was to evaluate the role of the MPA network in the Abrolhos Bank (Brazil) in relation to the FD of fish fauna. Underwater visual censuses were carried out in no-take, partially protected and unprotected zones. We used FD metrics to assess the MPA network in terms of FD in each zone. The functional hypervolume of the target fish species was calculated. From fishers’ information, we determined the Use Value of the main target species and proposed a Fisheries Functional Vulnerability Index (FFVI), which can indicate management priorities for the species at a local level. The results showed that MPAs maintained higher FD, especially in no-take areas. Two no-take sites showed significant functional divergence values, while one no-take site and one partially protected site showed greater functional richness than unprotected sites. A total of 23 target species accounted for 56% of the functional hypervolume. The FFVI indicated the most vulnerable species. The results indicate that functional metrics may be more informative for assessing the impact of fisheries. In addition, the findings reinforce the need to incorporate the local knowledge of resource users, as recommended by international institutions.

Resumo em Inglês:

Abstract Discarding unwanted catches is a significant issue arising from marine fishing activities, with far-reaching socioeconomic and ecological consequences. Uruguayan fishery regulations fail to penalize discarding but mandate self-reporting, providing an opportunity to analyze the discard from the two Uruguayan industrial bottom trawl fleets (shelf and coastal). By examining fishing logs, discard was estimated at 3,268 tons/year, accounting for 6.5% of the total catch (9.1% for the shelf fleet and 3.7% for the coastal fleet), with no discernible temporal trends for 2016, 2017, 2019, and 2020 nor significant seasonal variations in discard magnitude. Diversity, species richness, and evenness of the discard varied between fishing seasons and years. The most discarded species were Bassanago albescens in the shelf fleet and Brevoortia aurea in the coastal fleet. Both species showed magnitudes indicating a potential for exploitation development. Discard per unit of effort was mapped by fleet, enhancing the potential for discard information reconstruction for the area and thereby facilitating its inclusion in ecological and economic assessments. Discard reports have proven to be a valuable source of information that should be integrated into fisheries conservation and management initiatives.

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Abstract The Shortnose Guitarfish, Zapteryx brevirostris , is endemic to the Southwest Atlantic and its geographic range is commonly reported from Southeastern Brazil to Northern Argentina. However, range limits are imprecise or inconsistent in some cases. These inconsistencies were addressed in this study based on 1,363 specimens collected since 1865. These records were obtained from scientific collections, a systematic review of literature, and an on-board observation database. According to the data collected in this study, the known northernmost distributional limit of the species lies at the mouth of the Doce River, Northern Espírito Santo State, in Southeastern Brazil (19°S). As for the other extreme of its range, the known southernmost distribution limit refers to the Falkland Islands (Malvinas) (53°S). This represents more than 2,000 km of coastline geographic range extension — in comparison to the previous known southernmost range limit for this species. The geographical range of Z. brevirostris seems to follow biogeographic patterns operating at an ecosystem level in which biotic (especially in the north) and abiotic factors (especially in the south) play a role in imposing limits to its distribution range.

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Abstract This study aimed to conduct a comprehensive review of marine litter of Atlantic sandy beaches. We performed a bibliometric analysis from 1970 to 2023 to identify patterns, flaws, and knowledge gaps. A total of 185 studies were found but only 126 were included in the analysis according to exclusion criteria adopted. The earliest studies on Atlantic beaches were registered in the 1980s, being Marine Pollution Bulletin the major journal. Among the countries bordering the Atlantic Ocean, the highest number of studies were carried out in Brazil, Portugal, Mexico, and Spain. A significant finding that emerged from our study was the lack of standardized methodology adopted for studying anthropogenic litter on sandy beaches. This lack of standardization makes it difficult to compare results across different years and areas, highlighting the need for the development of new techniques and means to standardize future studies. Our study also discussed strategies for minimizing the presence of litter on beaches via coastal management and climate changes. It emphasized the importance of review studies in identifying gaps and guiding integrated and shared actions across the Atlantic region. Overall, this comprehensive review provides valuable insights into the status of anthropogenic litter in beaches of the Atlantic and highlights the need for standardization and collaborative efforts to address this persistent problem. By integrating scientific research with effective coastal management strategies, we can strive towards reducing anthropogenic litter and preserving the health and beauty of the Atlantic sandy beaches and worldwide.

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Abstract This study focused on the distribution of total suspended solids (TSS) concentration along the Ipojuca River estuary and on identifying the average location of the estuarine turbidity maximum (ETM) zone considering the seasonality of its rainfall and tidal regime. This research was carried out along a 13.6 km stretch of the chosen river, with 21 sampling stations during the rainy (Jun-Jul/17) and dry periods (Dec/17). Temperature and salinity data were obtained at each station using CTD profiling. Furthermore, current intensity and direction were measured using a current meter, and water samples were collected to determine TSS concentrations. The water column showed vertically homogeneous temperature (~27° C). Salinity distribution varied seasonally and along the tidal cycle throughout the system. The estuary shows a weakly to moderately stratified water column that intensifies itself upstream. At just 2.28 km from the river mouth (second station), salinity varies by 0.2-32.9. This stratification primarily stems from the constriction of its river mouth, trapping freshwater in its interior. Currents showed higher values during the rainy period (-5 to 95.8 cms -1 ). TSS concentrations were higher during the rainy season, ranging from 8.6 to 241.2 mg L -1 during spring tides and from 6.5 to 223.0 mg L -1 during neap tides. The ETM was located at 1.8-2.2 km from the river mouth during the rainy season and at 2-8 km during the dry season. The ETM coincided with the boundaries of salt propagation in the estuary, corresponding to salinities of 0.2-10, and longitudinal currents ranging from 60 to -10 cm s -1 , indicating the mixing zone of water masses. Since the ETM is also associated with the area of highest sediment deposition in the estuary, it is likely that most materials transported to the estuary that are associated with sediment transport remain trapped in this zone, making it an important area for further studies.

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Abstract Sterna hirundinacea , a seabird species, has been extensively studied in natural habitats; however, information on its reproduction in artificial environments is still limited. This study investigates the nesting behavior and reproductive success of S. hirundinacea at the Terminal Aquaviário da Petrobrás (TEBAR), an artificial site located on the north coast of São Paulo state, Brazil. From April to September 2021, 57 nests were selected for monitoring at 48-72-hour intervals from a total of 159 nests and 318 mature individuals reproducing within the colony. The breeding season lasted 145 days, with an average clutch size of 1.21 ± 0.41 eggs per nest, including single-egg nests (n = 45) and double-egg nests (n = 12). Nine instances of egg replacement were recorded. A total of 78 eggs were laid, with a mean length of 4.56 ± 0.22 cm, a mean width of 3.26 ± 0.09 cm, and a mean volume of 25.45 ± 2.01 cm³. The study documented a mean egg mass reduction of 0.39 ± 0.02 g per interval. Egg losses (n = 63) were attributed to predation (60.3%), inviability (34.9%), and stillbirth (4.8%). The mean incubation period was 23.73 ± 2.34 days. Of the remaining 15 healthy fledglings, 11 (73.3%) did not survive; causes of mortality included predation or falls into the sea (54.5%), collisions (36.4%), and natural causes (9.1%). Mortality peaked during the first nine days after hatching, further increasing at 21-30 days of age. Only four fledglings made it to flight, resulting in a reproductive success rate of 5.1%. TEBAR showed both similarities and differences in S. hirundinacea reproduction at the artificial site compared with natural nesting sites. Human activities at the site likely contributed to higher egg and fledgling losses due to predation and disturbance. Regular monitoring and further research are essential to assess the impact on S. hirundinacea and to develop conservation strategies if necessary.

Resumo em Inglês:

Abstract Marine Protected Areas (MPAs) in Brazil, like the “Refúgio de Vida Silvestre do Arquipélago de Alcatrazes”(REVIS de Alcatrazes), contain great species diversity. For conservation purposes, investing in local monitoring and surveillance is necessary. In this sense, Passive Acoustic Monitoring (PAM) has been used to collect acoustic data from marine environments. Therefore, this study assessed the frequency of vessels in the mentioned MPA in 2019 using PAM. Audio records collected by a hydrophone anchored at Saco do Funil (24°05’S; 45°41’O), located around 500 m from the main island of the archipelago, were used. Each audio file underwent a visual inspection of the spectrograms to detect the acoustic signals. The noise related to vessels transit was identified in 10% of the analyzed files, of which approximately 46% of the occurrences did not correspond to visits by the MPA management office. The area was most frequented from 6 am to 2 pm. The occurrence of non-official and unauthorized vessels was mostly concentrated from 3 am to 6 am and at 0 am. The study also underscored the biological significance of the MPA, revealing this area potential to be regularly visited by baleen whales in July and toothed whales throughout the analyzed months. So far, this is the only known surveillance investigation that used the PAM in MPAs along the Brazilian coast. Improvement and expansion of this technique use may lead using acoustics as an important auxiliary tool in monitoring MPAs on the Brazilian coast.

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Abstract Marine debris is one of the environmental problems highlighted in this decade. These pollutants are present in various environments worldwide, ranging from highly urbanized beaches to even the most remote islands. This study aimed to understand the factors involved in the origin and distribution of solid waste and microplastics via their characterization and quantification on beaches of three islands in southeastern Brazil: Trindade Island/ES, Grande Island/RJ, and Paquetá Island/RJ. These islands vary in their proximity to the continent and exhibit distinct patterns of occupation and use. Sediments were collected at three points in wet and dry sand on each beach and then analyzed and quantified. The results showed that the highest density of solid waste was 0.27 items.m -2 on Trindade Island, followed by Paquetá Island/RJ, with 0.10 items.m -2 , and Grande Island/RJ, with 0.07 items.m -2 . Plastic was the most abundant material on the three islands studied. The highest concentration of microplastics was found on Paquetá Island (21.98 items.kg -1 ), followed by Grande Island (8.85 items.kg -1 ) and Trindade Island (2.44 items.kg -1 ). The blue color and fragments were prevalent on the three islands, accounting for 31 and 74% on Trindade Island, 44 and 77% on Grande Island, and 31 and 68% on Paquetá Island, respectively. Microplastics smaller than 1,000 μm predominated on Trindade Island (76%) and Grande Island (68%), whereas, on Paquetá Island, microplastics with sizes ranging from 1,000 to 5,000 μm prevailed (62%). This research demonstrated that the abundance and distribution of solid waste and microplastics are determined by several factors, including oceanographic processes and anthropic influence, resulting from the different forms of use and occupation of the islands studied.

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ABSTRACT The carbon isotope composition of Dissolved Inorganic Carbon (δ13CDIC) is a useful tool to study the carbon budget in estuarine settings. Here we present the first set of δ13CDIC data from the Cananéia-Iguape Estuarine Complex (São Paulo, Brazil), a changing environment undergoing freshening at a rate of the order of 770 m3 s-1. We measured δ13CDIC values of water at 15 stations distributed across the area, both during neap and spring tide, in May 2015 and April 2017. The spatio-temporal variability of δ13CDIC suggests a conservative mixing of two water endmembers, freshwater with δ13CDIC = −10 ‰ (V-PDB) and seawater with δ13CDIC = +2.0 ‰ (V-PDB). Linear regression of δ13CDIC vs. salinity predicts the δ13CDIC values of open ocean surface water from the nearby Santos Basin and suggests that the freshwater and seawater endmembers mix at 1:1 proportion in the estuarine complex. Mixing was the dominant process governing the behavior of δ13CDIC values, whereas photosynthesis, degradation of organic matter, and CO2 uptake or outgassing did not play a significant role. In particular, phytoplankton production had no impact on δ13CDIC, suggesting that the ecosystem was exempt from eutrophication. Long-term freshening in the NE sector of the estuary did not significantly impact the δ13C values of DIC. These results underline the need for long-term measurements of δ13CDIC in the study area to contribute to the understanding of the evolution of the estuarine complex, whose freshening trend could be enhanced by extreme precipitation events linked to climate change.

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ABSTRACT Thenus spp. are slipper lobsters which are commercially significant as a food source with good aquaculture potential. This study focuses on collecting population information on Thenus orientalis and Thenus indicus from selected sites in southern Thailand and Malaysia to inform sustainable fisheries management about the resources. Twenty-five size-adjusted morphometric measurements were analyzed using canonical discriminant function and dendrogram cluster analyses to examine patterns of phenotypic variation between sites. Significant phenotypic variation with distinct centroids and minimal overlapping cases were observed among four sites of T. orientalis (p < 0.05), as well as cluster analysis groupings occurring as in (i) Kota Kinabalu and Kudat, in Sabah, Malaysia; (ii) Pattani; and (iii) Nakhon Si Thammarat, in Thailand, which were best discriminated by the width of the third pereiopod merus, the sixth abdomen segment, and the carapace posterior margin. Similar morphometric data between Kota Kinabalu and Kudat suggests a subpopulation of T. orientalis occurring in Sabah waters. Significant phenotypic variation was also detected between six sites of T. indicus (p < 0.05), with close centroids and overlapping cases forming three groups: (i) Ranong and Nakhon Si Thammarat; (ii) Kota Kinabalu, Tanjung Sedili, and Kuala Terengganu; and (iii) Pattani, best described by the widths of the second antenna and the first pereiopod merus, in addition to the length of the sixth abdomen segment. Cluster analysis shows the Pattani specimens clustering with the Malaysian specimens rather than the Thai specimens, suggesting homogeneous morphometric data between contiguous sites. Nakhon and Pattani forming separate groups in both species suggest discreet subpopulations occurring in the lower Gulf of Thailand. Patterns of phenotypic variation observed may be attributable to environmental conditions, local adaptations, and nomadic behavior. The findings can serve as baseline information for spatial planning in fisheries management, as well as to apprise regional efforts in the sustainable exploitation of Thenus spp.

Resumo em Inglês:

Abstract The COVID-19 pandemic led to a reduction in human mobility, known as “anthropause.” Few studies have compared birds’ community patterns between lockdown and “new normal” periods, especially in extremophile environments. This study presents the first baseline by monitoring coastal birds on 10 beaches along the largest hypersaline lagoon in South America. The birds were counted in September and October 2021 (during a lockdown period) and in October 2022 (after the lockdown – “new normal”) during the morning. The continuous route transect methodology was applied by the same observer in all beaches. The Analysis of Covariance (ANCOVA) was used to investigate the response of community abundance to urbanization (raster-based variable) and time of COVID-19 pandemic (lockdown vs. new normal). Rarefaction curve and Permutational Analysis of Variance (PERMANOVA) were used to compare community richness and composition, respectively, between lockdown and new normal periods. Generalized Linear Models (GLM) with negative binomial distribution were applied to test the effect of the same predictors on the three more abundant species. The bird community structure and composition did not change when comparing lockdown and new normal periods, mainly due to dominance of synanthropic species. Among species-specific responses to lockdown, the Southern Lapwing Vanellus chilensis was more abundant during the lockdown on six of the nine beaches where it occurred. Oppositely, the Kelp Gull Larus dominicanus and the Neotropic Cormorant Nannopterum brasilianus were more abundant in new normal period, reinforcing that these species benefit from human subsidies. This may provide a unique opportunity for science-based sustainable ecotourism activities in urban areas with synanthropic species, capitalizing activities such as birdwatching, that would certainly contribute to environmental education actions.

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Abstract Sponge-ophiuroid ecological associations, which are important in the dynamics of marine populations and communities, have been recorded for a long time. In this study, we report new records of interactions between sponges and ophiuroids, which were obtained by analyzing biological collections, to increase knowledge about the associations between these animals. The study observed 14 interactions between sponges and ophiuroids, eight of which are new to science: Ophiocnida scabriuscula and Agelas sp., Ophiothrix sp. and Monanchora arbuscula, Ophiactis quinqueradia and M. arbuscula, O. quinqueradia and Callyspongia ( Cladochalina) aculeata, Ophiactis savignyi and Agelas dispar, O. savignyi and M. arbuscula, O. savignyi and Topsentia ophiraphidites, and O. savignyi and Dysidea etheria. The specimens found were collected in four areas of the northeastern Brazilian coast (tropical southwestern Atlantic), including a conservation area and a mesophotic coral ecosystem. Thus, the continuation of studies and the implementation of conservation strategies for these environments are essential. Finally, the importance of biological collections as a crucial data source for biodiversity studies is reinforced.

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ABSTRACT In this study, the length-weight relationships (LWRs) and length-length relationships (LLRs) of 16 marine fish species-important component of fishery production models-were estimated. The specimens were collected monthly from commercial gillnet fisheries from November 6, 2018 to October 30, 2019 in Vietnamese waters. In total, 7,426 individuals had their total length (TL), fork length (FL) and total body weight (W) measured. LWRs were calculated using the logarithmic transformation of the linear regression equation logW = loga + b*logTL, while LLRs were determined using a linear regression model: TL = a + b*FL. In addition, 95% confidence intervals (CIs) were estimated for the model parameters. The results showed that all regression parameters were highly significant (p < 0.001), with coefficients of determinations (R 2 ) > 0.9412 for all species. The a (intercept) values ranged from 0.0025 to 0.4, and the b (slope) values ranged from 2.53 to 3.28. TL and FL were highly correlated (p < 0.001 and R 2 > 0.9422 for all parameters), and a and b ranged from -9.12 to 15.85 and 0.87 to 1.45, respectively. The results provide the key morphology parameters, which are beneficial for fishery researchers and managers in stock assessment, administration and conservation.

Resumo em Inglês:

ABSTRACT Abstract: Rhithropanopeus harrisii (Brachyura, Panopeidae) is a small euryhaline and eurythermal omnivorous crab native to the Northwest Atlantic. However, it has become an invasive species in various estuaries and coastal areas far from its original habitat, most likely due to intercontinental shipping. Once it establishes itself in one location, it can spread to neighboring regions via maritime currents. In 1982, this species was found in South America, specifically in Lagoa dos Patos, Brazil. In this study, we present the first record of R. harrisii larvae in Uruguay, located in the coastal marine zone of Laguna de Rocha, approximately 300 km south of Lagoa dos Patos. It was discovered during a study that involved 15 plankton samplings, conducted from February 2016 to February 2017. Notably, the observation of R. harrisii larvae was limited to the coastal zone during the summer and autumn of 2016 (February to April). All observed larvae were in the zoeal stage, and their abundance ranged from three to 185 individuals per 100 m3. The temperature and salinity values recorded during sampling surveys with the presence of R. harrisii ranged from 19 to 22.4 °C and 11.8-32.5 ppt, respectively. The discovery of the larval stage suggests that adults of this species may be reproducing in the eastern coastal zone of Uruguay or nearby regions. The area in which they are currently found could potentially serve as a biological corridor, facilitating their spread to other estuaries of great economic and ecological importance, such as the Río de la Plata, as well as other coastal lagoons and subestuaries in Uruguay and Argentina. Further monitoring studies are necessary to determine whether this species became established in the area. Potential ecological consequences in our region derived from its presence are herein discussed.

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ABSTRACT Sewage pollution is an increasing problem for Perna perna mussel farmers in Brazil, and there is an urgent need to adopt post-harvest treatments, such as depuration, to reduce the associated microbiological risks. However, depuration of this species has been discouraged by experiences showing that the animals usually spawn during this procedure, bringing difficulties for water treatment and making them lighter, weakened, and undesirable to be traded as a live product. This study aimed at developing a protocol to prevent mussels from spawning by modulating the water temperature during depuration. For one year (from 2021-07-07 to 2022-06-29), market-size mussels harvested from the Brazilian southern coast were divided into groups of five and immersed during 50 hours in sets of experimental units (15 L acrylic aquariums) that emulated depuration tanks with different water temperatures (ranging from 8°C to 31°C). During this period, the experimental units were inspected nine times to check for spawning/spawned mussels. Analysis of the overall results showed that 21 (95.5%) out of the 22 assays resulted in mussels spawning and that this behavior was mostly recorded (80.3%) within the first 5:30 hours of the assays. The models developed (binary logistic regression) indicate that conditioning the depuration water to temperatures 5°C lower than those registered at the harvest site holds the potential to reduce the chances of spawning by more than 50%, and these chances drop to 8.2% when this difference reaches 10°C. Further studies are needed to show how reducing water temperature during depuration influences its efficiency in terms of pathogen reduction, aiming to define the best protocol to optimize microbial removal and minimize spawning.

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ABSTRACT This study encompasses the description and evaluation of the length-weight relationship of 104 demersal fish species caught by bottom trawlers targeting shrimps on the southeast continental shelf of Brazil from 2004 to 2006. The regression criteria describing the length-weight relationship for each species were classified as approved (met the criteria), approved with reservations (partially met the criteria), and not approved (did not meet the criteria) based on linear regression parameters to determine whether length is a viable predictor of weight. A total of 141,433 individual fish, comprising 44 families and 104 species, were sampled; the beta parameter (± se) varied from 0.22 ± 0.12 to 3.94 ± 0.19, and the alpha parameter varied from -4.09 ± 0.04 to 0.89 ± 0.02. In total, 22 species were not identified by a recent large survey (2019) conducted in the study area. The results of this study are significant for the management of fishery resources, mainly due to the occurrence of unusual species, the economic importance and enormous effort exerted by the trawling fleet in the region, and the substantial sample size, in which a large number of individuals per species were caught.

Resumo em Inglês:

ABSTRACT The objective of this study was to identify the squids caught by shrimp trawlers in Sergipe and to describe their populational structure. Four samples were obtained monthly from commercial trawlers based in Pirambu-Sergipe (May/2015-May/2016). Each squid found was separated, identified, weighed individually (wet weight - WW in g) and had its mantle length (ML; cm) and total length (TL, including tentacles; cm) measured. One specimen of Doryteuthis pleii was captured (23.3 cm ML mature male), as well as 152 specimens of Lolliguncula brevis (1.5˗6.7 cm ML). The linear relation between TL and ML of L. brevis was TL=5.1173+2.6190ML (positive allometry) and the power relation between WW and ML was WW=0.1453ML2.5353 (negative allometry). For L. brevis, there were two cohorts in the area during the period analyzed. Studies on the biology of cephalopods are scarce in northeastern Brazil, especially considering that these species are present in the bycatch of shrimp fishing and that the global conservation status of L. brevis is data deficient (DD) according to the International Union for Conservation of Nature (IUCN).

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Abstract The introduction of species beyond their natural distribution area as a result of human activities is one of the main threats to marine biodiversity. In 2019, Perna viridis , an Indo-Pacific mytilid, was recorded for the first time in the coast of Brazil in Guanabara Bay (Rio de Janeiro State). In 2021, this species was recorded in the Northeast region of Brazil (Fortaleza, Ceará State). This record was subsequently replicated in studies from 2022, 2023, and 2024. The specimens from Ceará State were deposited in the malacological collection “Prof. Henry Ramos Matthews - Série B” of the Universidade Federal do Ceará. During a curation activity of this collection, these specimens were reanalyzed and their identification questioned. Therefore, this study aimed to confirm the record of P. viridis for the Northeast region of Brazil. According to the analyses, the individuals collected on the coast of Ceará are not P. viridis , but belong to Mytella strigata , a native species of the coast of South America. Thus, the occurrence of P. viridis in the Southwestern Atlantic remains restricted to the southeast region of Brazil.

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Abstract Guiana dolphins in the Costa Verde estuarine complex of southeastern Brazil are relatively well-studied, but there is still limited knowledge about their movement patterns between the two management units in the region. This study was based on the identification of the individual dolphins that transited between the two Costa Verde management units. Dolphins were photo-identified within the study area from 1994 to 2020, and two photo-identification catalogs were compiled based on this material. These catalogs were systematically compared on the finFindR software, which found 80 individuals that had transited between both management units, between 904 in Sepetiba bay and 808 in Ilha Grande Bay. The most common type of movement was a one-way (no return) movement from Sepetiba to Ilha Grande bay (62.5 %).

Resumo em Inglês:

Abstract The blackfin tuna ( Thunnus atlanticus ) is a small epipelagic species restricted to the western and central Atlantic Ocean that has aggregative behavior, living in large schools usually associated with other tunas and commonly caught near moored Fish Aggregating Devices (FAD) or natural floating objects. This work offers the first report of a blackfin tuna school following a fishing boat serving as a drifting FAD in the southwestern tropical Atlantic Ocean, which occurred during the tagging campaign for the Atlantic Ocean Tropical Tuna Tagging Program (AOTTP) in May 2019. The blackfin tuna school followed the boat for approximately 190 nautical miles during almost 60 hours. The school remained close to surface when the boat was in motion but moved to deeper waters (60 m) in those few moments when the boat remained drifting. Along with the tagging activities, which occurred mainly in the morning, we caught 17 blackfin tunas with size ranging from 46 to 58 cm fork length (FL) (mean ± SD: 52.47 ± 3.35 cm FL) and weight ranged from 2.3 to 4.04 kg (3.2 ± 0.5 kg).

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Abstract In 2021, rubber bales appeared along the Brazilian coastline, causing environmental impacts. In this research paper, we identified a Second World War shipwreck that was associated with this event. Numerical simulations provided robust evidence to support the hypothesis that the origin of the 2021 bales was the MV Weserland . Moreover, it was sunk to a depth of approximately 5,000 m with a cargo containing rubber, tin, and wolframite. Tin is currently considered a strategic metal, with prices rising from USD 13,375/t in March 2020 to USD 34,462/t in May 2021. We provided evidence that the departure of rubber bales from the wreck and the increase in the price of its metal cargo were temporally associated; this reinforced the hypothesis of deep-sea unauthorized salvage in international waters (areas beyond national jurisdiction). The novel results demonstrate that historical shipwrecks are ticking time-bombs with risks of high and unmapped pollution in oceans worldwide.

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Abstract Mangrove is an important transitional ecosystem between terrestrial and marine environments, with a typical vegetation (mangrove) that tolerates the intense variation of salinity coming from the tides. The application of remote sensing techniques based on spectral indices enables the development of spatiotemporal monitoring of this vegetation, thus subsidizing ecosystem management. This study aimed to evaluate the spatiotemporal analysis of mangrove vegetation in RESEX Acaú-Goiana based on spectral indices. The study area was the mangrove in RESEX Acaú-Goiana, a protected area of sustainable use in northeastern Brazil between the states of Pernambuco and Paraíba. Images from the TM/ Landsat 5 and OLI/Landsat 8 sensors from 1992, 2006, 2010, and 2019 were used and the normalized difference vegetation (NDVI), normalized difference water (NDWI), and modular mangrove recognition indices were applied. NDVI varied from 0.5 to > 0.75; NDWI, from 0.25 to 0.75; and MMRI, from −0.6 and −0.3. 2019 showed the lowest average of these indices. The evolution of the establishment of carciniculture (shrimp farming) nurseries in the inner portion of the reserve becomes evident, which may result in environmental damage to the ecosystem. Results will serve as input for developing monitoring strategies and managing the reserve.

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Abstract This article provides the first records of courtship behavior and a mating event of free-ranging whitespotted eagle rays ( Aetobatus narinari ) in Brazilian waters. These observations shed light on utilizing the marine no-take zone surrounding the Anchieta Island State Park as a mating site in the South Atlantic region. Sightings of the species in shallower areas notably increased throughout summer months (from January to March, 2023 and from January to February, 2024), which aligns with its known reproductive period. Specifically, the mating event occurred in March 2023, followed by observations of courtship behavior in January 2024. While the population dynamics and impact of fisheries remain poorly understood, the species is frequently captured by traditional fishing fleets and traded locally. This reiterates the importance of the local Marine Protected Areas (MPAs) and underlines the urgency for their expansion, alongside the need for further studies that support specific management actions.

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Abstract Despite their worldwide distribution, the occurrence of Lamnidae species in tropical zones remain poorly understood. In the Equatorial Southwestern Atlantic, the Shortfin Mako, Isurus oxyrinchus , has been captured in commercial fisheries, whereas the White Shark, Carcharodon carcharias , is only rarely recorded. This study aimed to characterize lamnid records for the Equatorial Southwestern Atlantic, as well as to apply molecular markers to identify a lamnid carcass from the only area in the region where these two species are known to overlap (off Ceará State, Northeastern Brazil). The landed carcass, although sold in the market as a White Shark, in fact was a Shortfin Mako, I. oxyrinchus , with a total of 99.6% and 100% match to its ND2 and D-loop mitochondrial DNA sequences, respectively. Despite the existence of a record of landings of elasmobranchs by artisanal and commercial fisheries from Ceará, lamnid landings in this region are still rare and comprise only four records for I. oxyrinchus , including juvenile specimens. As for the White Shark, Ceará State remains the only region in the Equatorial Southwestern Atlantic to hold records (three) of C. carcharias (all of them adults). Oceanographic conditions in this region may contribute to the occasional presence of large lamnid specimens. Moreover, fishers seem to support the presence of both lamnid species in the region.

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Abstract Human-wildlife conflicts pose significant challenges, requiring nuanced solutions rooted in ecological understanding and community engagement. In this sense, this opinion essay explores the first documented South American conflict scenario between Neotropic cormorants ( Nannopterum brasilianum ) and artisanal fisheries, located on Laguna Estuarine System, southern Brazil. Local reports converge on the information that, after 2015, Neotropic cormorants began to establish a reproductive colony on a non-breeders dormitory located at Noca Lagoon, near the estuary mouth. The colony’s consistent presence over the years and intense feeding activity, along with possible recruitment of cormorants, may lead to the perspective of increased population and nuances among fishermen. These concerns include vegetation suppression dealt by guano deposition, food competition, property damage, and fishery resources depletion. Despite no evidence of cormorant population increase and due the fact that fishing is an important regional activity, there was a response from local lawmakers to address this issue (Municipal Ordinary Law number 2.154/2020). The law imposes the harmful status to the native bird species and permit measures to “clean” harmful populations from properties. In addition, this law lacks control guidelines to cormorant populations, threating the local biodiversity and exacerbating the emerging human-wildlife conflict. To address these challenges, holistic and interdisciplinary approaches that understand cormorant behaviors and its interaction with fisheries activity are needed. From the knowledge bridge built from lawmakers, stakeholders, scientists, and fishermen, it is possible to foster dialogue and adopt a conceptual framework to mitigate conflict outputs and promote harmonious coexistence between wildlife and human activities.

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ABSTRACT Magnetic experiments have provided insight into the preservation of magnetite in sediments of the Inner Sea of the Maldives during early diagenesis. In this study, we present high-resolution remanence data on the upper 15 meters of the sedimentary record and a detailed magnetic characterization of discrete samples from the top 5.5 meters of the International Ocean Discovery Program (IODP) Site U1471 record. Based on magnetic experiments, it can be concluded that magnetite is rapidly reduced, with a large decrease in natural remanent magnetization (NRM) related to destruction of primary NRM below the upper two meters of the sedimentary record. In thermomagnetic experiments, the appearance of a greigite signal at 3.06 meters below sea floor (mbsf) suggests that current diagenesis could imprint nearly 100 kry of error on the chronology based on magnetostratigraphy. Furthermore, based on X-ray fluorescence data, it can be concluded that magnetite reduction did not affect the Fe record.

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Abstract Tsunamis, despite their rarity, are among the deadliest natural disasters, inflicting catastrophic damage on both coastal and inland regions. Given their highly site-specific impact, a comprehensive understanding of tsunami wave flow characteristics is crucial for effective tsunami preparedness and for safeguarding civil engineering structures. This study investigates the formation and progression of tsunami bores as they transition into surges near the shore. We employed a wave-flume experimental approach, with a specific focus on the Malaysian coastline. Experiments took place in a wave flume with a length of 40 m and a platform designed to replicate the gentle slopes commonly found in Malaysian coastal areas vulnerable to tsunamis. The primary focus lied in measuring key flow parameters, including flow depths and velocities near the shore. Wet bed bores were marked by a sudden rise in water depth and considerable air entrainment in the front region. As these waves transformed into dry bed surges, the front slope became gentler, and aeration diminished, while peak velocities increased. Additionally, the study also delves into the relations between flow depth and velocity concerning Froude numbers and momentum flux. The outcomes contribute significantly to global initiatives aimed at improving coastal resilience against tsunamis.

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Abstract The Indonesian Cable-Based Tsunameter (InaCBT) is the most recently developed innovative prototype that has been deployed in the Flores Sea north of Labuan Bajo, Flores Island, Indonesia. Two ocean bottom units (OBU) were attached to a single fiber-optic cable. The first one is 34.0 km from the shore at a depth of 2100 m (LB-01) and the second one is 54.2 km from the shore at depth of 4110 m (LB-02), respectively. Each OBU comprises one deep-sea bottom pressure recorder (BPR); a three-axis accelerometer; and temperature, humidity, and leakage sensors. Since deployment, the InaCBT has detected at least three near-field and distant earthquake events. One of them, the M7.5 Banda earthquake (EQ), detected on January 9, 2023, resulted a rise of the sea level recorded at six coastal tidal stations around the location. Near real-time analysis applies Lanczos filtering to split EQ signals (high frequency) and tsunamis (low frequency, if present). EQ wave signals dominate at 10-14-second wave periods. Using data from Banda EQ, the low-frequency wave shows an oscillation that probably indicates the presence of a tsunami wave. The identification and distinction of EQs and tsunami can be done by directly filtering raw data without detiding and by using harmonic analysis. The 30-50-second cut-off period can separate EQ and tsunami signals.

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Abstract The organization of fish communities into habitat use groups facilitates a replicable understanding of species distribution due to the distinctive characteristics and ecological roles of these groups. Partitioning beta diversity and assessing both species contribution to beta diversity (SCBD) and local contribution to beta diversity (LCBD) can evaluate the ecological importance of each group and measure the uniqueness of each site. This study aimed to comprehend how different habitat groups within the marine fish assemblage in the Ubatumirim Bay contribute to beta diversity and to correlate the uniqueness of each sampling site to their attributes to better understand the importance of habitat use groups and the community composition variation in the bay. We sampled ichthyofauna at six locations within the bay, employing a shrimp trawl net at varying depths. We categorized the 95 identified species into five distinct habitat groups: reef-associated, pelagic-neritic, demersal, benthopelagic, and pelagic-oceanic, each with different ecological characteristics and preferences. However, no significant differences were detected in SCBD among these groups. An increase in LCBD values was observed with the decrease in mean sediment diameter, indicating a higher environmental complexity, possibly acting as an environmental filter. One of the sampled sites, Couves Island, stood out with a significantly higher LCBD value, which underscores the importance of such diverse environments in maintaining regional biodiversity. These findings can serve as a valuable baseline reference in conservation planning and management, particularly in assessing the effectiveness of the recently established Marine Environment Protection Area. For instance, comparing the current observations with future surveys could quantify the impact of this protection initiative, thus providing evidence of management efficacy and showing the potential effects of impacts (such as predatory tourism) in the Ubatumirim Bay area.

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Abstract The presence and potential adverse effects of emerging contaminants, such as UV filters and synthetic musk fragrances, in aquatic ecosystems has generated increasing concern. However, information about the sublethal effects and ecological risks of these substances to non-target organisms remains scarce. A systematic review of oxidative biomarkers was performed to better understand the mechanisms of these contaminants in bivalves. Bivalves were chosen as the focus of this study because they can provide integrated information related to contamination by ecotoxicologically relevant substances over time. Bibliographic database searches resulted in 10 articles published from 2019 to 2023. The biomarkers superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase showed promising responses (increase or decrease) in the presence of UV filters (oxybenzone, enzacamene, and octocrylene) and fragrances (galaxolide and tonalide). Glutathione S-transferase showed the most significant increase in response to these compounds, making it the most promising biomarker. Our results indicate a limited number of studies on the toxicity of personal care products, highlighting the need for further research in this area.