Resumo em Inglês:

Abstract Scientific diving (SD) is defined as any diving activity that applies scientific procedures to produce subsidies for studies and technical works in underwater environments. The first report of an underwater scientific study in Brazil dates to the 19th century, in the Abrolhos reefs. Currently, in Brazil, scientific diving has been performed in various areas, from shallow coastal regions to remote and sometimes hard-to-reach places, such as oceanic islands, flooded caves, and icy areas like Antarctica. However, the regulation of SD in Brazil still lacks more concrete actions towards an effective and efficient self-regulation that offers physical safety to practitioners and institutional safeguards for organizations that use it in their research projects. Thus, this article aims to contribute to a better understanding of this critical issue in Brazil and to serve as a reference and incentive for the training of professionals and the development of these activities in the country. It includes: 1) a historical review of SD; 2) a diagnosis of the training and application of SD in Brazil; 3) the evolution of marine sciences in Brazil from the perspective of SD; 4) a review of the use of environmental assessment and underwater conservation techniques in oceans and internal waters; 5) an analysis of the evolution of scientific diver training in Brazil, including a diagnosis on training; 6) the history and updates of the rules, regulations, and safety of SD. Given all the potential of diving combined with specific techniques for research, monitoring, and marine and limnic science in Brazil, we aim to understand the evolution of scientific diving teaching and to outline perspectives in the country, as it is crucial for the training of qualified scientists capable of performing these underwater tasks. Finally, we present future plans for the development of this activity in Brazil from the point of view of research and the labor market.

Resumo em Inglês:

Abstract Reviews can be useful to provide an overview of specific knowledge areas to facilitate research guidelines and the comparison of study results. Therefore, we aimed to detect regions, environments, and taxonomic groups of elasmobranch that lack information on their feeding ecology and consequently need further attention. Using specific keywords on diet and feeding studies, we searched for articles on the trophic and feeding ecology of elasmobranchs. We found an increase in studies over the last 24 years, with an emphasis on stomach contents and stable isotopes. The USA, Australia, Mexico, Argentina, and Brazil were the countries with the highest number of published articles. Australia, the USA, Argentina, Brazil, Mexico, South Africa, Spain, Uruguay and India were the countries with the highest number of species studied. Estuarine and freshwater environments seem to need more attention, since studies on species in these environments were scarce (~3%). The total number of shark and ray species studied showed no significant differences (164 and 186, respectively), but most of the articles reviewed concerned sharks (67.5%). The larger elasmobranch families also need more attention, especially demersal species such as Rajidae, Dasyatidae, Arhynchobatidae, and Sycliorhinidae. Feeding studies only analyze some of the data deficient (DD) species (~7%) included in the IUCN Red List, pointing to the need to obtain more information about them.

Resumo em Inglês:

Abstract This study analyses the feeding ecology of Brevortia aurea (Brazilian menhaden) larvae during a reproductive season in the Río de la Plata estuary (RPE), and explores its changes along larval development. Data were obtained from stomach content analyses of 205 individuals collected with a Bongo net during spring 2001. Larvae were discriminated into preflexion (PF), flexion (F) and post-flexion (PsF) stages. Feeding was described using complementary metrics like Feeding incidence (FI), the Relative Importance of different prey types consumed (IRI), the Degree of prey digestion (E) and Diet overlap (D), which were estimated and compared between stages. Also, larval morphometric relationships (body length, BL vs mouth width, MW) and between MW and maximum prey width (Wmax) were established for the range of observed larval sizes. The overall FI was 46.3% and increased with the development stage: 40.4% PF, 63.3% F, 78.6% PsF. Feeding occurred mainly during sunlit hours but no clear daily cycle could be established. Copepods and in particular Acartia tonsa were well represented among ingested preys, followed by invertebrate eggs and nauplii. Prey diversity and overlap between stages tended to decrease as development progressed. B. aurea exhibited isometric growth of MW in relation to BL. Average Wmax was 222.5 µm ± 100.9 SD, and increased non-linearly with both BL and MW. Gape size alone did not seem to be the limiting factor for prey choice (size), and we hypothesize that factors involved in the feeding mechanism other than mouth gape and linked with capture performance substantially influence the feeding ecology of this species in the RPE.

Resumo em Inglês:

Abstract The degradation of tropical coastal lagoon systems in urban areas of the least developed countries has been associated with an increase in impermeable areas and poor domestic sewage treatment, increasing land-based runoff of nutrients and suspended solids from catchments. This study aimed to assess the biogeochemical changes caused by human interventions through the analysis of the spatial distribution of sedimentary phosphorus (P) and its mass balance in the Itaipu lagoon, located on the east coast of the state of Rio de Janeiro. Human intervention in the Itaipu lagoon system has caused severe imbalances in biogeochemical cycles over the past decades. Watercourses have been channeled to normalize the hydrological regime and increase hydraulic energy, improving sediment transport capacity. In this context, the increase in runoff from the coastal urban basin into the Itaipu lagoon has buried an increasing amount of phosphorus in the sediment. Recently, a regional increase in storm events caused a series of landslides and floods, which have been reported as possible consequences of global climate change. In recent decades, the synergy between landslides and river channeling has increased TP loads, accelerating phosphorus settling and changing P spatial distribution in surface sediments. This has accelerated siltation of the lagoon with an accumulation of nutrients and organic matter, leading in some cases to sediment anoxia. The lagoon has undergone strong eutrophication, changing its trophic state from meso- to hypertrophic in less than 30 years, even though P loads are not as high as in other coastal lagoons. Our findings confirm that human intervention impacts nutrient loads, which in turn disrupt the balance of biogeochemical cycles, compromising coastal water resources. This leads to the collapse of ecosystem services, another step towards degrading planetary boundaries.

Resumo em Inglês:

Abstract Although we are currently in the Decade of Ocean Sciences for Sustainable Development, Chile seems to be lagging behind in marine education. Research has shown the importance of animal imagery in generating a bond between students and their environment, and strengthening interest in conservation. The objective of this study is to contribute to ocean literacy research in Latin America, by describing coverage of ocean content in the Chilean primary school curriculum and textbooks. Content analysis was undertaken concerning textual and pictorial materials. Learning Objectives of the science primary curriculum were reviewed, and the number and type of fauna species shown in images were recorded. For each textbook, we recorded the number of marine and terrestrial animals, categorized endemic, native, and exotic species, and whether the name of the animal was labeled with the image. The results show that only three Learning Objectives of the primary curriculum explicitly define content associated with the ocean. Of the total animal images, slightly more than twenty percent are marine fauna. The great majority of the marine animals shown are native, however, most of the time the image is not reinforced with the name of the species. Considering that school textbooks are the foundation of formal education, this preliminary study indicates that there is a content deficit when teaching about the relevance of the ocean and its animal species in primary school textbooks in Chile, covering only three ocean literacy principles in the science curriculum. However, this study recognizes that important improvements have been made in prioritizing natural science teaching with images of native species.

Resumo em Inglês:

Abstract Studies relating the populational structure of target species to operational and environmental variables contribute directly to the management of the fisheries in these resources. Therefore, this study aimed to provide data on fishing and ecology of the swordfish ( Xiphias gladius) caught by the Brazilian longline fleet operating in the western Atlantic between 2010 and 2016. Generalized additive mixed models were used to evaluate the relationship between explanatory variables and responses based on Catch Per Unit of Effort (CPUE) data. Results show that the Brazilian longline fleet catches the swordfish mostly between latitudes of 5°N to 30°S and longitudes of 20° to 50°W and that the swordfish prefers temperatures under 25°C at depths below 60 meters. The species showed a tendency toward intermediate light intensity, predominating in the crescent moon phase, and a preference for areas with low chlorophyll concentrations. Our findings on operational and environmental interactions with swordfish CPUE suggest areas and times that can be used by fishing fleets and government institutions as a starting point for swordfish management strategies.

Resumo em Inglês:

Abstract Mangrove forests play a critical role in natural disaster resistance and provide meaningful livelihoods for local communities, especially integrated mangrove shrimp farming (IMSF) systems. Organic shrimp certification actually increases the value chains of shrimp farming in addition to ameliorating mangrove–forest management. Identifying technical issues and assessing environmental risks are the leading concerns when considering organic shrimp production certification. In this study, the technical practices of 30 households were investigated, and surface water and sediment samples were collected in the IMSF models and adjacent rivers in the Thua Duc Forest Management Board area, Ben Tre Province. Data collected from shrimp farming ponds and the environmental background were referred to both the Naturland and National Standards. The results showed that the average mangrove forest and shrimp pond ratio was 56.90:42.70 (%). Two technical issues were highlighted: (i) the use of rotenone, known as a toxin to kill undesirable fish before stocking shrimp, and (ii) annual shrimp pond regeneration causing increased pollution. The data showed that higher concentrations of TSS and P-PO4 3- were detected in surrounding rivers, while surface water in either IMSF ponds or adjacent rivers slightly surpassed the permissible levels of total Fe concentration. All parameters—including heavy metals; toxic and persistent parameters; oil and grease and coliforms analysed in surface water, and sediment samples—were lower than the detection and permissible levels. The results provided evidence that the IMSF’s practices and environmental characteristics were suitable for recommending the Naturland Standards. Recommendations and technical interventions for farmers are necessary to help reduce Fe levels and the safe use of rotenone in IMSF systems. An environmental quality monitoring programme at the target area should be applied when launching organic shrimp production.

Resumo em Inglês:

Abstract Knowledge of the feeding habits of pelagic fishes off the Brazilian coast is scarce, making the analysis of trophic interactions often inaccurate. Here, we investigated the diet and trophic role of 12 pelagic fish species by revisiting samples obtained by the ECOSAR II Program (FURG/IO/IBAMA) between 23°S and 28°40'S, an area also known as South Brazil Bight. In addition, we analyzed their biomass and fisheries landings in order to examine shifts over time. The content of 432 stomachs was analyzed at the lowest taxonomic level possible. The frequencies of occurrence were used to cluster species, revealing three trophic guilds: "Planktivorous Clupeiformes", "Planktivorous Carangiformes", and "Piscivores". Most Carangidae consumed mainly copepods and other small crustaceans, except Selene setapinnis which clustered in the piscivorous guild together with Scombriformes specimens. In terms of biomass, the dominance of Trachurus lathami, Sardinella brasiliensis, and Trichiurus lepturus was evident. The species' trophic levels ranged from 2.98 to 4.5, showing that these fishes occupied intermediate to high trophic position. Comparing fisheries landings in two study periods (1986-2002 and 2003-2019), six species showed a decrease, while three an increase. Correlations between landings of the Brazilian sardine (Sardinella brasiliensis) and other pelagic fishes indicate that when the former's decreases, the catch of alternative species, such as Opisthonema oglinum and Chloroscombrus chrysurus, increases. The intermediate position of small pelagics in the food web may affect the availability of commercial species by controlling the abundance of lower and upper trophic-level organisms. These findings fill essential gaps for ecosystem modeling, suggesting that ecosystembased fisheries management should address multispecies issues of the pelagic realm rather than only singlespecies approaches. Combining past survey data with yield trends provides evidence for both natural and humaninduced ocean changes.

Resumo em Inglês:

Abstract The aim of this study was to investigate the main factors that influence the latent heat fluxes (LHF) in the Tokar Gap in the central part of the Red Sea. From 2000 to 2020, ERA5 reanalysis data on summer months of the Central Red Sea were used to match the time when the Tokar Wind Jet appeared. The diurnal variability of the Tokar Gap peaks in the early morning. The time series data of the wind speed showed that the Tokar Wind Jet appeared from July to August. The empirical orthogonal functions (EOF) analysis method was used to determine the modes of LHF variabilities. The sum of the first two modes of variability explained ~ 90.8% of the total variance. The first mode explained 80.8%, whereas the second mode represented approximately 9.9%. To examine the contribution of sea surface temperature (SST) and wind speed to the first two EOF principal components, the correlation coefficient and determination coefficient were applied. The results showed that SST had a CC of 0.90 and a DC of 81.99%, whereas wind speed showed a CC of 0.35 and a DC of 12.80%. These results may be explained by the strong link between SST and the specific humidity differences of saturation and actual vapor pressure. Partial correlation results indicate that there is an indirect relation between wind and LHF. In this study SST was the dominant factor, influencing LHF variability in the study area.

Resumo em Inglês:

Abstract The abundance and movement patterns of lemon sharks ( Negaprion brevirostris) at Lama Bay, Biological Reserve Rocas Atoll, were reassessed by visual census. We considered tides and daylight periods to plan our observations during two expeditions in 2015. Using daily visual counts, the mean abundance of individuals was 29 in austral summer (maximum 35) and 31 in winter (maximum 41). The results indicated that the local lemon shark population might have recovered after 18 years of a substantial drop in mean abundance. In addition, the movement pattern of the species corroborated previous studies related to their fidelity to the birthplace. These results justify the need of continuous monitoring of lemon sharks over the course of time at Rocas Atoll using non-lethal and non-invasive techniques.

Resumo em Inglês:

Abstract Plastic bags, bottles, packing tapes, and fishing lines are at the forefront of the discussion on plastic pollution in the oceans. However, scientific interest on the role of cotton buds in such context is rapidly increasing, as these objects continue to be widely used and discarded improperly. Therefore, this study aimed to determine the abundance and fate of cotton buds as a case study in the Küçükçekmece Lagoon. At two sampling stations, the pebbly beach and the rocky beach, a total of 854 cotton buds were found over the course of six months with an average value of 71.16 litters m -2 per month. The similarity of months of occurrence in summer and autumn was statistically significant. However, in November and December, when meteorological conditions were more severe, significant similarity was observed. Furthermore, the results of the potential environmental hazard, risk assessment, and carbonyl index were used to provide answers to the main problems of cotton bud pollution. Consequently, the hazard level was classified as either III or IV and the risk level was determined unfriendly. In total, 44.5% of the samples had a high level of oxidation. EDX analysis also confirmed that the biofilm influenced the accumulation of metals on the plastic surface. Overall, the results have addressed the issues that should be considered in improving the management strategies for plastics, which can be implemented to reduce the environmental impact of plastics and achieved the main objective of raising awareness on the accumulation of plastic waste generated by anthropogenic activities in coastal areas.

Resumo em Inglês:

Abstract We evaluated the seasonal phosphorus (P) status of the plankton community in the Ombla Estuary (OE) by using its specific alkaline phosphatase activity (sAPA). Microphytoplankton (MICRO) indicated a substantially higher P deficiency than nanophytoplankton (NANO) and picoplankton (PICO). We found that the prolonged increase in the temperature of the surface estuarine water supported a notable growth of the dinoflagellate Prorocentrum spp. in late spring-early summer (June). In the summer (August), we found the maximum microphytoplankton sAPA (MICRO sAPA) (307.8 nmol μg C-1 h-1) in the surface water, in which (84%) dinoflagellates predominated within MICRO with the maximum alkaline phosphatase activity (APA) in all size fractions, including free enzymes. Persistently low discharge of Ombla during summer-early autumn caused a transition from phosphorus- to potentially nitrogen-limited MICRO in the surface water in early autumn (October). Nutrient stress disappeared in winter, in which a significant amount of dissolved orthosilicate, dissolved inorganic nitrogen (DIN), and soluble reactive phosphorus (SRP) enriched the estuary via maximal river discharge and inflow of nutrient-rich coastal waters. MICRO (coccolithophorids and diatoms) had very low APA (surface water) and quantitatively undetectable APA (bottom water) in the nutrient-rich water column in January. This study shows a more significant impact of nutrient concentrations on MICRO than other size classes of the plankton community. Because of the similarity in seasonal hydrological features, we assume that the general pattern of switching from P- to N-limitation of phytoplankton growth also occurs in other highly stratified estuaries along the coastal karst of the eastern Adriatic Sea during the lowest river discharges and groundwater activities in summer-early autumn before the rainy season. This study indicates that a common highly stratified estuary on the eastern Adriatic coast can serve as a natural laboratory to explore connections between nutrient limitations and phytoplankton successions.

Resumo em Inglês:

Abstract The bearded fireworm Hermodice carunculata is widely distributed across tropical and subtropical Atlantic and Mediterranean Oceans and was previously considered to be mostly associated with shallow reefs. We provide here data on the distribution, abundance and habitat use of H. carunculata across a euphotic-mesophotic gradient (0-90 m) in the Saint Peter and Saint Paul’s Archipelago (SPSPA, Mid Atlantic Ridge, Brazil). Samples were obtained using SCUBA and a Remote Operated Vehicle (ROV). A total of 189 individuals were observed and a sharp increase in abundance with depth was recorded, particularly from 50 m depth onwards. In the mesophotic zone (50-90 m) individuals were closely associated with branching black-corals (Tanacetipathes spp.) and predation over black-corals and the scleractinian Madracis decactis was commonly sighted. A Boosted Regression Tree model indicated black-coral abundance as the main driver of H. carunculata abundance, suggesting that preference for optimal habitats to hide/forage is more important than depth per se on the bathymetric distribution of the fireworm. The high abundances of H. carunculata in the mesophotic zone, and its predation on keystone benthic cnidarians, suggests that this species play important roles in the dynamics of deep reefs.

Resumo em Inglês:

ABSTRACT Knowledge of coastal hydrodynamics is essential for understanding the processes of transport of dissolved or particulate material since in these areas there are large ports and the vessel traffic with a greater possibility of accidents. Studies related to currents are of fundamental importance to support decision-making to mitigate environmental impacts. The present work aims to test the technique of measuring currents through drones, as it has the advantage of a quick response in obtaining and analyzing data. For this study, a field survey was carried out in the region of the mouth of Lagoa dos Patos, RS, Brazil. The method's validation was done through the use of a colored tracer in which it was used to measure the surface current velocities simultaneously with the vectors generated by the drone. The results obtained a percentage difference between the methods of 10%, both for speed and for current direction, showing to be very promising for the use of drones to obtain surface current fields. In this way, it opens a new perspective in carrying out field experiments, so new experiments will be carried out to verify the feasibility of using this technique in different conditions, such as in the surf zone and areas with the presence of density fronts.

Resumo em Inglês:

Abstract The 2004 Sumatra-Andaman earthquake (9.3 Mw) and subsequent tsunami caused upliftment and subsidence throughout the Andaman and Nicobar archipelago. This incident has significantly impacted the mangroves (97% vegetation loss) and coastal ecosystems of the Nicobar archipelago. Interestingly, the coastal subsidence has also created new intertidal habitats in the erstwhile agricultural lands and terrestrial forests, which provided an opportunity for the colonization of mangrove species. During our long-term monitoring of mangrove colonization in the Nicobar archipelago, we collected Aegiceras corniculatum (L.) Blanco (Primulaceae) from Alreak, in Nicobar Islands. The occurrence of this species forms a new distributional record for the Nicobar archipelago. The present article provides detailed information on its taxonomy, ecology, and discusses the potential future spread of this species in the Nicobar Islands.

Resumo em Inglês:

Abstract Dimensions of particulate matter found in the water column of marine and freshwater environments (the pelagic realm) range from nanometers to tens of meters. Included in this enormous size range are miniature bacteria, phytoplankton (photosynthetic microalgae), mixoplankton (mixotrophic microorganisms), micro- to meter sized drifting animals (zooplankton), plastic particles, detrital aggregates and fecal pellets, fish, whales and many others. These particles and organisms are involved in many different processes and perform a multitude of services, such as in oceanic biogeochemistry (carbon fixation, oxygen production, carbon export and others) or human nourishment (fisheries). Digital optical tools used in pelagic imaging approaches now allow to bridge this enormous size span and to image micro- to meter-sized objects in situ or on discrete samples. Monitoring plankton, nekton, and particle dynamics at spatial and temporal scales that enable effective management of marine and freshwater environments poses a collective challenge for society. We here argue that a global, distributed and operational network for pelagic imaging is needed and within reach, and we provide recommendations how it can be attained via the voluntary activities of the pelagic imaging community and strategic support from funding agencies and other stakeholders.

Resumo em Inglês:

Abstract The three-dimensional variability of the subaerial beach is examined for Stanwell Park Beach, New South Wales (NSW), Australia. This embayed environment has previously been studied over long time scales (decades), but not over shorter time scales (days, weeks). Embayed beaches experience rotation events during which opposite accretion and erosion patterns are observed at the extremities of the beach. To analyse this phenomenon, the beach is mapped with 10 Real-Time Kinematic Global Positioning System (RTK-GPS) surveys collected from 10th February 2016 to 14th May 2016. This study aims to examine short-term changes (days, weeks) to the morphology of the subaerial beach of Stanwell Park Beach and any factors that may influence its behaviours. We show that a short-time beach rotation event occurs over one month, caused by a large eastern swell. However, swell with a southern direction generates rip current channels on the subaerial beach face. During this particular event, the amount of sediment transported is lower than during beach rotation events. Furthermore, Stanwell Park Beach has two lagoons that can open to discharge water accumulated in these lagoons. We show that during heavy rainfall, the lagoons open, transporting sediment in surf zone and thus causing erosion. This study provides a clear demonstration of the sensitivity of embayed beaches to short-term variability in wave climate.

Resumo em Inglês:

Abstract The iAtlantic Project has established an international collaborative strategy to improve mapping and characterization of deep and open ocean ecosystems in understudied regions of the Atlantic and evaluate their health. In December 2022, the first iAtlantic expedition in the South Atlantic set off to map and explore seafloor ecosystems in the Santos Basin slope (200-1,000 m depths) in collaboration with the Petrobras ‘Santos Basin - Regional Characterization Project.’ The 17-day ‘iAtlantic_BR10-Petrobras’ cruise was conducted on board the research vessel NPqHOc Vital de Oliveira (Brazilian Navy) and performed (a) water column structure characterization, (b) seafloor morphology mapping, (c) description of benthic habitats and communities by seafloor imagery and biological/ geological sampling, and (d) ex-situ experiments to assess the functioning of sedimentary ecosystems and their responses to climate-related environmental changes. This study describes the rationale behind the iAtlantic_BR10-Petrobras cruise science plan, reports its sampling strategy and methods, and summarizes its collected data and preliminary results.