Abstract The exploited mangrove crab Ucides cordatus, an important ecosystem engineer in South American mangroves, has a biphasic lifecycle with pelagic larvae developing offshore. Megalopae return to the mangrove forest to settle, i.e., metamorphose into benthic juveniles but its environmental drivers remain poorly understood. We postulate that conspecific crabs facilitate recruitment. In the field, we investigated whether the number of recruits is higher near conspecific burrows than in areas without conspecific bioturbation. Recruit sampling was conducted monthly from April 2008 to May 2009 along an environmental gradient. First, U. cordatus recruits of that year emerged from March to July. Intraspecific facilitation was indicated by significantly higher recruit numbers in bioturbated than in non-bioturbated substrates. Recruits were most abundant in zones with intermediate conditions of inundation, leaf litter standing stock, sediment consistency, luminosity, temperature, salinity, and pH. Avoidance of more inundated zones likely reduces predation by fishes and of less inundated zones helps individuals escape more stressful, drier environmental conditions. The observed habitat-specific recruitment pattern must be considered when designing field assessments of the population structure of U. cordatus (which should include sampling recruits) and enhancing stocks by releasing laboratory-cultivated larvae and first juveniles into the wild.

Abstract This study aimed to review previous records of Polydora species from Brazil, as well as provide new records, mainly from the Southeast and South regions of the country. In total, 11 species were distinguished and a key to their identification is given. Polydora cornuta , P. nuchalis , and a new species from the state of Rio de Janeiro, P. nonatoi sp. nov. were found to occur in silty sand tubes in soft sediments; six species were found to be opportunistic commensals boring in shells of various molluscs; P. colonia was found to only bore in sponges; and a new species, P. paulolanai sp. nov., was found to bore in both sponges and oyster shells in Paraná state. Adults of P. nonatoi sp. nov. have black stripes on the palps, black spots on the peristomium and 3−4 anterior chaetigers, short occipital antenna, falcate spines of chaetiger 5 with a large lateral tooth connected to main stem by thin sheath, and only capillary chaetae in the posterior notopodia. Adults of P. paulolanai sp. nov. have black bands on the palps, short occipital antenna, falcate spines of chaetiger 5 with transverse subdistal collar on concave side, and numerous needle-like spines loosely held in tufts in addition to capillary chaetae in the posterior notopodia. Polydora caeca Webster, 1879 is resurrected and treated here as a senior subjective synonym of P. neocaeca Williams & Radashevsky, 1999. Shell-boring worms from Brazil earlier identified as P. neocaeca or P. cf. haswelli Blake & Kudenov, 1978 are referred to P. caeca . The urgent need of molecular data for the correct identification of Polydora species from Brazilian waters is highlighted.

Abstract The study of benthic meiofauna has been undertaken in Latin America since the beginning of the 20th century, recently gaining attention due to its recognized role on the ecological functioning of meiofauna assemblages. Bibliometric data provide information regarding research results, explain the degree to which a subject has advanced, and identify its major strengths and weaknesses. In Latin American countries, this type of review is scarce for meiofauna communities. This study analyzes knowledge of marine meiofauna by focusing on the documents Latin American authors published from 1990 to 2021. Documents from three bibliographic databases were analyzed to obtain the most relevant bibliometric indicators. Moreover, the interrelationships between authors, countries, and concepts were analyzed using science mapping techniques. Latin American research on marine meiofauna has increased since the 1990s, producing a total of 399 documents over three decades by almost 1,000 authors. Brazil produced the majority of these documents (predominantly published by Brazilian authors and institutions). The number of documents by country was associated with five development indicators. Their main sources and keywords indicate that ecology, oceanography, and biogeography were the main addressed topics, especially on deep marine environments. Most productive authors were clustered into main research groups with varying degrees of links. We conclude that research efforts on marine meiofauna are gaining importance despite the small number of documents by a relatively low number of research groups. We found a high centralization of documents by countries and a relation with four indicators, such as country size and research spending. Greater regional collaboration could further expand the knowledge of marine meiofauna in Latin America.

Abstract Drones have proven to be versatile tools for scientific studies aimed at assessing the environmental quality of various ecosystems. This study diagnosed the restinga vegetation in the coastal municipality of Pontal do Paraná, in the state of Paraná, Southern Brazil. This vegetation, which extends over 21.72 km of the coastline of the municipality, was grouped into eight sectors to optimize 27 drone flight plans. The images obtained were transformed into orthomosaics and classified into eight classes, following the random forest classifier: herbaceous, shrubby, arboreal, sand, degraded area, irregular construction, water, and other. We observed 289.11 ha of restinga, of which 183.66 ha (63.5%) corresponded to conserved areas and 105.45 ha (36.5%), to a total degraded area with irregular constructions, vegetation suppression, and introduction of exotic species. Sectors 1 and 5 showed the lowest (8.19 ha) and highest (21.00 ha) values of degraded areas, respectively. Sectors 6 and 8 were the most critical: their degraded areas exceeded the conserved areas of restinga by 4.15 and 3.95 ha, respectively. The main causes of the degradation n in this study refer to irregular occupation. Drone images are a valuable tool for environmental management and vegetation analysis of difficult-to-access sites.

ABSTRACT Sandy beaches have different shoreline change rates (i.e., erosion/accretion rates). An erosive process on beaches poses risks for human-occupied areas. One example is Matinhos Beach (state of Paraná - Brazil), which has an average annual erosion rate of around 1.5 m yr-1 This study applied a methodology that combines in situ measurements and numerical modeling to simulate the physical processes in the coastal area of Matinhos during the 2018 Austral winter. Monthly DGPS surveys were carried out in the study area from June to September. The MOHID modeling system was applied to simulate hydrodynamics and sediment transport, considering waves and tidal forcing validated with in situ data. The WAVEWATCH III and SWAN models were applied in a nesting approach to simulate the waves at Matinhos Beach. The GFS was used to assess the wind conditions. The study period showed a dynamic evolution of accretion and erosion between monthly measurements with no clear pattern in most profiles. Significant sand accumulation was observed near the headland. Morphological changes were minor due to the predominance of low energy without significant storm events. The measured morphological changes are in line with the residual littoral drift obtained from the modeling results for the period. The residual current velocities were towards the southwest, with magnitudes ranging from 0.15 m s-1 to 0.2 m s-1. A slight variation in the angle of wave incidence (10°) may change the direction (southwest or northeast) and intensity of the littoral drift. The applied methodology can reduce uncertainty and support effective coastal management. However, the seasonal scales of wave climate cannot be disregarded, nor can the need for coastal oceanographic data.

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.

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.

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.

ABSTRACT We present the first report of plastic biomedia contamination on Brazilian beaches based on evidence collected from 14 beaches of the Paraná state coastline (southern Brazil). Plastic biomedia, also called biocarriers, are small, perforated plastic pieces used worldwide in wastewater treatment plants (WWTP) that apply the Moving Bed Biofilm Reactor (MBBR) process. Accidental release of these particles into the environment adds to Ocean’s long-term plastic pollution problem. A high amount of plastic biomedia presence in the coastal areas of Paraná was first noticed by a community member, who found 411 plastic particles on a beach located in Pontal do Paraná, bringing this issue to our attention. In this study, plastic biomedia was retrieved from drift line alongshore transects (0.3 to 1 km long) and cross-shore transects (5 m wide) from the water line to the backshore zone. A total of 749 items were collected from 11 of the 14 sampled beaches, including the Mel and Superagui Islands nature reserves. The decreasing trend in plastic biomedia abundance with the increase in distance of the PEC southern outlet suggests that these particles probably originate from a WWTP in the Paranaguá Estuarine Complex (PEC). Once in the water, these floating plastic particles that followed the suspended sediment transport pattern were exported to coastal waters and were transported by longshore currents. Highlighting the potential role of the PEC as a substantial vector for marine debris to the Paraná coastline. The most likely source of this novel plastic contaminant to the Brazilian coastline are WWTP with MBBR systems. Therefore, stakeholders need to discuss and establish a reporting system so that plastic biomedia spillovers or losses are reported, and its dispersal in the environment is reduced.

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.

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.

Abstract Of the 20,000 species of Annelida, most live in salt water, and the minority inhabits freshwater or terrestrial environments. Among the freshwater representatives, the family Aeolosomatidae draws attention mainly due to its enigmatic phylogenetic position. In the 1940s, Prof. Ernst Marcus was a pioneer in the study of Aeolosomatidae, mainly from collections in the state of São Paulo, Brazil. His research resulted in the description of eight species, four of which were new to science. Later, Marcus’ description of Aeolosoma headleyi was recognized as a fifth new species by Van der Land ( 1971 ) and named Aeolosoma marcusi in his honor. Recently, during a visit to the Museum of Zoology of the University of São Paulo (MZUSP), we found the original material deposited by Marcus ( 1944 ), but not formally registered. Thus, the aim of this work was to redescribe and designate the lectotypes and paralectotypes of Aeolosoma gertae Marcus, 1944 and Aeolosoma sawayai Marcus, 1944. We were able to study and photograph the specimens using a light microscope with Differential Interference Contrast (DIC). We were also able to identify and redescribe many important taxonomic features. However, some structures can only be observed in living individuals (as they are not preserved in the fixed material), which reinforces the need to study live specimens. This paper contributes to understand the diversity of Aeolosoma , provides new morphological knowledge and lays the foundation for new approaches to the study of aeolosomatids.

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.

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.

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.