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Biofouling in freshwater and marine environments developed on man-made aquatic surfaces causes significant economic losses. Still, this problem is magnified when it comes to invasive species, such as the golden mussel. One of the alternatives to combat it is the use of antifouling solutions; however, the vast majority focus on solutions for the marine environment. In this same context, natural antifouling solutions from macrophytes have been reported as promising to combat estuarine biofouling; however, trials with freshwater organisms are still incipient. Thus, this study evaluated the performance of 25 macrophyte extracts in inhibiting the formation and/or eradication of bacterial biofilms, settlement of the golden mussel (Limnoperna fortunei), as well as its toxicity effect on three different non-target model organisms of three trophic levels. Among the 25 extracts, nine demonstrated ≥ 60% inhibition of biofilm formation, with only the extracts of Typha domingensis and Eichhornia crassipes having a biofilm inhibitory effect of ≥ 70% for bacterial isolates and ≥ 60% for multispecies biofilms. Planktonic growth had distinct responses, ranging from induction, inhibition, and no effect on growth. The T. domingensis extract showed quorum sensing inhibition (QSI) with a dose-dependent relationship, while the E. crassipes extract showed QSI only at a dilution of 1.2%. These same extracts prevented the golden mussel from attaching and showed safe concentrations of 35.35% for Pseudopediastrum boryanum and Daphnia magna and 70.71% for Pimephales promelas. This study highlights the biotechnological potential of macrophyte extracts as a sustainable and environmentally harmless alternative for the control of micro and macrofouling in freshwater environments., Competing Interests: Declarations. Ethical approval: According to Brazilian legislation (Law 11,794 of October 8, 2008), research with invertebrates does not require authorization from any ethics or animal welfare committee. The collection of invertebrates was approved by the Brazilian Agency SisBio (process no. 77095–1). The assay with P. promelas was approved by the Consejo Nacional del Ética Animal (CNEA) – Ata n° 17/11. Consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Co-author Ng Haig received research support from the National Council for Scientific and Technological Development – CNPq (Process 404233/2021–0), and co-author Grasiela Lopes Leães Pinho received research support from the Mixed Technical Commission of Salto Grande and Latitud (Uruguay Technological Laboratory Foundation – LATU)., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Dissolved organic carbon (DOC) is a key component of the biogeochemical carbon cycle in the Southern Ocean. However, there are still significant gaps in understanding the role of DOC in polar environments, due to the limitations of spatiotemporal sampling. In this study, we investigated the regional aspects controlling the distribution and diffusive and advective fluxes of DOC along the northern Antarctic Peninsula (NAP) during austral late summers of 1995 and between 2015 and 2019. DOC concentrations ranged from 33.1 to 157.6 μmol kg-1. The NAP showed regional differences in both its hydrographic conditions and DOC distribution. The regional variability reflected the main biogeochemical sources and fates of DOC associated with the Antarctic Circumpolar Current inflows, the Weddell Gyre transport and the meltwater input. The intensity of the advective fluxes of DOC was 106 times greater than the diffusive fluxes. However, ocean fronts along NAP environments are mesoscale structures for observations of downward and upward diffusive fluxes of DOC. This study adds insights on the role of DOC as a proxy for a better understanding of the coupling between physical and biogeochemical processes over time in an environment sensitive to climate change.

Organotin compounds (OTCs), such as tributyltin (TBT) and triphenyltin (TPhT), are released in aquatic environments from antifouling coatings and can cause imposex, an abnormal condition where female snails develop male sexual characteristics. This study investigates temporal variations in imposex incidence along the Colombian Caribbean coast following the 2008 global ban on TBT-based antifouling paints. Over a 12-year period, we assessed imposex in 1,384 adults snails from six species (58% female and 42% male) during 2012, 2016, and 2023. In 2012, just four years after the ban, imposex incidence in some sites reached 100% in the neogastropods Purpura patula, Stramonita haemastoma, Stramonita rustica, and Thais deltoideia. In 2016, imposex in some sites reached 81% for the mesogastropod Strombus pugilis and 39% for the neogastropod Melongena melongena. By 2023, imposex decreased for the first four neogastropods, persisted for S. pugilis, and increased for M. melongena only in Cartagena Bay and the Tolú marina. These findings indicate a general decline in imposex over time, aligning with the ban, but also suggest potential new sources of contamination as imposex rates increased in some previously unaffected areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Phylogenomics has the power to uncover complex phylogenetic scenarios across the genome. In most cases, no single topology is reflected across the entire genome as the phylogenetic signal differs among genomic regions due to processes, such as introgression and incomplete lineage sorting. Baleen whales are among the largest vertebrates on Earth with a high dispersal potential in a relatively unrestricted habitat, the oceans. The fin whale (Balaenoptera physalus) is one of the most enigmatic baleen whale species, currently divided into four subspecies. It has been a matter of debate whether phylogeographic patterns explain taxonomic variation in fin whales. Here we present a chromosome-level whole genome analysis of the phylogenetic relationships among fin whales from multiple ocean basins. First, we estimated concatenated and consensus phylogenies for both the mitochondrial and nuclear genomes. The consensus phylogenies based upon the autosomal genome uncovered monophyletic clades associated with each ocean basin, aligning with the current understanding of subspecies division. Nevertheless, discordances were detected in the phylogenies based on the Y chromosome, mitochondrial genome, autosomal genome and X chromosome. Furthermore, we detected signs of introgression and pervasive phylogenetic discordance across the autosomal genome. This complex phylogenetic scenario could be explained by a puzzle of introgressive events, not yet documented in fin whales. Similarly, incomplete lineage sorting and low phylogenetic signal could lead to such phylogenetic discordances. Our study reinforces the pitfalls of relying on concatenated or single locus phylogenies to determine taxonomic relationships below the species level by illustrating the underlying nuances that some phylogenetic approaches may fail to capture. We emphasize the significance of accurate taxonomic delineation in fin whales by exploring crucial information revealed through genome-wide assessments., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society of Systematic Biologists.)

Sea ice is a critical component of the cryosphere and plays a role in the heat and moisture exchange processes between the ocean and atmosphere, thus regulating the global climate. With climate change, detailed monitoring of changes occurring in sea ice is necessary. Therefore, an analysis was conducted to evaluate the potential of using the Gray Level Co-occurrence Matrix (GLCM) texture analysis combined with the backscattering coefficient (σ°) of HH polarization in Sentinel-1A Synthetic Aperture Radar (SAR) images, interferometric imaging mode, for mapping sea ice in time series. Data processing was performed using cloud computing on the Google Earth Engine platform with routines written in JavaScript. To train the Random Forest (RF) classifier, samples of regions with open water and sea ice were obtained through visual interpretation of false-color SAR images from Sentinel-1B in the extra-wide swath imaging mode. The analysis demonstrated that training samples used in the RF classifier from a specific date can be applied to images from other dates within the freezing period, achieving accuracies ≥ 90% when using 64-bit grayscale quantization in GLCM combined with σ° data. However, when using only σ° data in the RF classifier, accuracies ≥ 93% were observed.

Dispersal patterns of zoonotic pathogens can be strongly influenced by mobility and contact among hosts. Toxoplasma gondii infection has been documented in many avian species, however, there is little information regarding free-living seabird populations. Leptospira can infect domestic and wild animals, with birds being potential carriers of the bacteria. The continental shelf of the southwestern Atlantic Ocean is a foraging area for seabirds that breed locally, as well as migratory seabirds wintering in the area, which may come into contact with each other in prey aggregation areas and contribute to T. gondii and Leptospira spread. Therefore, this study aimed to investigate the prevalence of two important zoonotic pathogens in free-living seabirds. Blood samples were collected from 322 birds of three local breeders (Phaethon aethereus, Sula leucogaster and S. dactylatra) in the eastern coast of Brazil (Abrolhos Archipelago), and two migratory species using the area during the pre-laying (Pterodroma arminjoniana) and the non-breeding periods (Thalassarche chlororhynchos). Serological agglutination tests for detection of anti-Toxoplasma gondii and anti-Leptospira spp. antibodies were performed. None of the seabirds in this study was seroreactive to Leptospira spp., whereas 34.5% (n = 111) of the animals presented antibodies anti-T. gondii. Antibody titers in seropositive birds ranged from 10 to 640. There were seropositive birds in all sampled localities. This study provides the first records for P. arminjoniana and T. chlororhynchos as seropositive to T. gondii, suggesting their potential role as sentinels for the environmental contamination by T. gondii and also T. gondii infection. These findings indicate the circulation of the parasite in the Brazilian coastal and oceanic regions, probably due to the ingestion of T. gondii oocysts by birds, the epidemiological involvement of migratory birds as hosts of pathogens, as well as the role of the historical introduction of invasive vertebrates on Brazilian islands. Therefore, due to the serological evidence of infection, the dynamics of toxoplasmosis in seabirds, regarding their susceptibility towards the disease and the possible anthropogenic influence need to be better understood for the colonies to be included in the wildlife cycle of T. gondii., Competing Interests: Declarations Ethics approval and consent to participate This study adopted the Ethical Principles in Animal Research according to Brazilian College of Animal Experimentation and was approved by the Ethical Committee for Animal Research of the Faculty of Veterinary Medicine, University of São Paulo (Protocol No. 9959300821); Animal Use Ethical Committee at FURG (P040/2018) and Animal Use Ethical Committee at UFRGS (37905) with authorization of the Chico Mendes Institute for Biodiversity Conservation, Brazil (Sisbio No. 64381–2; 64234–9). Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Microplastics (MP) are omnipresent in aquaculture and can induce several toxic effects, mainly oxidative stress. Therefore, alternatives to minimize these effects are welcome. In this study, chitosan (1 and 3 g/kg) was supplemented through the feed of farmed shrimp P. vannamei for 30 days. After this period, the shrimp were exposed to MP (0.5 mg/L) for 7 days. The results showed the presence of MP in hepatopancreas, gills and muscle. Hepatopancreas morphological alterations, as well as lipid peroxidation, a decrease in GSH level, and an increase in SOD activity indicated an oxidative stress that was reversed by chitosan. The muscle was also affected by MP, showing decreased CAT activity and increased SOD activity, though no lipid peroxidation was observed. In muscle, chitosan reversed the SOD increase to basal activity. The results obtained showed that chitosan was more effective against oxidative stress than in preventing accumulation and histological damage., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Juliane Ventura Lima reports was provided by Federal University of Rio Grande. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Morphologically similar species that occupy resource-limited environments tend to differ in their ecological traits in order to coexist, which may result in differential exposure to environmental threats. For instance, partitioning of feeding resources may influence contaminant exposure and bioaccumulation in marine predators through different diets or foraging habitats. Here, we sampled three tropical seabird species breeding in sympatry in the southwestern Atlantic Ocean for blood and feather trace element concentrations (As, Hg, Cd, Pb), and assessed their foraging ecology with bio-logging (GPS tracks and time-depth recorders), analysis of regurgitated prey, and carbon and nitrogen stable isotope mixing models. Red-billed tropicbirds (Phaethon aethereus), brown (Sula leucogaster) and masked (S. dactylatra) boobies differed in their preferred foraging locations, the range of foraging trips, diving parameters and diets. In addition, interspecific differences were detected in blood or feathers for all trace elements analyzed, suggesting influence of the differences observed in diet and space use. Red-billed tropicbirds had the largest foraging range over the continental shelf and over the slope, suggesting lower exposure to continental sources of metals. Brown and masked boobies had higher Hg concentrations than tropicbirds, higher δ 15 N values (a proxy for trophic level), and δ 15 N correlated with Hg levels, suggesting biomagnification of Hg along the food chain. Nonetheless, red-billed tropicbirds showed comparable levels of As and Cd in blood or feathers, and higher levels of Pb in both tissues in comparison to boobies, which may suggest overall exposure of seabirds in the region, through their diets and foraging areas. Resource partitioning is critical for allowing coexistence of different seabird species in shared breeding sites where they act as central-place foragers. Nonetheless, in scenarios of environmental pollution, these species-specific strategies lead to differential bioaccumulation, and thus distinct effects of pollution on populations are expected., Competing Interests: Declaration of competing interest Authors declare they have no conflict of interest in publishing this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The ingestion of debris by marine fauna is a growing threat to biodiversity. This study aimed to evaluate and characterize litter ingestion by odontocetes from the Western South Atlantic. Between 2018 and 2022, 154 stomachs from six species were collected from stranded individuals and incidental captures. Stomach contents were analyzed with the naked eye and items of anthropic origin found were counted and physically/chemically characterized. Generalized Linear Models were used to evaluate the influence of biological factors on the presence/absence of litter in stomachs, and for Pontoporia blainvillei only, the influence of these factors on the number of ingested items was also tested; additionally, a temporal analysis of ingestion was done for this species (1994-2022). A total of 156 items, mainly macro-sized plastics made of polypropylene, were found in 52 stomachs of four species: Tursiops spp. (FO% = 3.3%), Steno bredanensis (10.0%), Delphinus delphis (28.6%) and P. blainvillei (47.5%). The presence/absence of litter was explained only by species (χ 2  = 28.29 and p < 0.001). For P. blainvillei, a threatened species in the region, the number of items was positively influenced by individual size (χ 2  = 6.01 and p = 0.01) and sex (χ 2  = 7.93 and p = 0.005). There was an increase in plastic ingestion by this species over the years (χ 2  = 121.6 and p < 0.001) and it was estimated that 75% of P. blainvillei stomachs will contain plastic by 2040. The ingestion of litter by odontocetes from the Western South Atlantic was confirmed and the potential risks posed by this type of pollution were evidenced, especially since these species also face other anthropic pressures. These results further demonstrate the increasing threat of litter in the ocean and highlight the importance of circularity of plastics and proper waste management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The intensification and expansion of changes in land use and land cover (LULC) can reduce the availability and quality of natural habitats and ecosystem services (ES). These changes have generated environmental damage in different parts of the world, especially in biomes more susceptible to modifications, such as the Pampa biome in the extreme south of Brazil. The Pampa biome has been neglected by environmental protection laws, despite its broad ecosystem and social importance. In this study, we used InVEST models to map and quantify five ES provided (i.e., water supply, carbon stock, groundwater stock, sediment retention and habitat quality) by 14 watersheds distributed in the Brazilian Pampa biome as well as determine ES hotspots by summing the areas with high provision of ES. We identified low availability of water supply and groundwater stock in practically the entire study area. High sediment retention and carbon stock were reported in areas with the presence of native vegetation. In addition, despite the large degraded areas, we observed high habitat quality associated with native vegetation in all studied watersheds. The hotspots varied spatially in the study area according to the proposed scenarios, the supply and the overlap of ES. Scenario 1 (>50% of ES) presented a larger area of high provision of ES. In contrast, scenario 2 (>75% of ES) presented smaller patches of areas with high provision of ES distributed across different watershed. We observed that large territorial extensions with high and medium provision of ES are vulnerable to the negative effects of LULC. Our study presented scenarios that indicate areas of high provision of ES, contributing to a more practical application, being a simplified and useful tool that can assist conservation and sustainable policies., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The Patos Lagoon estuary is a highly significant ecosystem where freshwater from a vast and densely populated area continuously flows into the Atlantic Ocean by coastal plumes, exporting not only freshwater but also sediment, nutrients, plastics, and other contaminants. In this work, numerical modeling tools together with field data were used to assess for the first time the capacity of the coastal plume to export microplastics (MPs) to the inner shelf under different hydrodynamic conditions. Two field surveys were conducted during plume events to quantify MP concentrations and validate the model approach. A bottom-up approach was employed to estimate the potential MP export from the estuary's domain to the Atlantic Ocean. MP concentration in surface plume waters ranged from 0.20 items m -3 to 1.37 items m -3 , confirmed by FTIR as synthetic polymers in a 90 %, being Polypropylene (PP) and Polyethylene (PE) the most abundant in a 73 %. The accumulation pattern was observed on the plume's frontal system, consistent with simulation results. The estimated average MP potential export rate attained 9.0 million items day -1 during moderate plume events and 47.5 million items day -1 during high discharge plume events. Strong discharge events, coupled with intense northeast winds, facilitated rapid southwestward export of MPs. Conversely, moderate to weak discharge events retained MPs closer to the estuary's mouth, enabling either longer trajectories or earlier deposition. Significant MP accumulation hotspots were identified in the gyre between the jetties and Cassino beach, as well as in the saline front within the plume boundaries. These accumulation zones may function as reservoirs for MP particles, potentially posing threats to local ecosystems. Understanding these dynamics is crucial for ongoing monitoring efforts to assess potential harmful interactions over time., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Climate and anthropogenic impacts are prevalent in marine and estuarine ecosystems. Rapid environmental changes have altered biological diversity and the ecological services associated with ecosystems around the world. The consequences of these impacts on estuarine ecosystems are worrying, given that estuaries are essential habitats for maintaining the diversity of species functions, as they act as sources for larger ecosystems through the recruitment and replacement of species. Through long-term standardized monitoring (1996-2019), we evaluated the temporal variability of the functional structure of fish species in a subtropical estuary using Principal Component Analysis (PCA), and their relationship with environmental, climatic, and anthropogenic variables using Generalized Additive Models (GAM). We investigate the hypothesis that natural disturbances associated with El Niño events and anthropogenic ones related with changes in the estuary morphology will lead to a decrease in the diversity of functions of the fish assemblage in the Patos Lagoon Estuary in south Brazil (32°S). Our findings suggest an overall downward trend in the fish functional structure, especially in the second half (2006-2019) of the time series, which seems to be associated with a combination of abiotic effects (salinity and temperature), global climate phenomena (ENSO phases) and anthropogenic impacts (changes in the morphology of the estuarine mouth and its connection with the sea). These findings rise concern considering the current climate change scenario, where phenomena such as El Niño may become more frequent and intense. Therefore, the evidence from this study suggests that extreme natural climatic events in synergy with anthropogenic disturbances may imply biodiversity losses over time and, consequently, loss of ecosystem processes in a subtropical estuary., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study investigated the impact of ocean acidification on the photodegradation of three microplastics (MPs): polypropylene (PP), expanded polystyrene (EPS), and ethylene-vinyl acetate (EVA), under accelerated UV radiation at three pH levels (i.e., 8.1, 7.8, and 7.5), simulating marine conditions. The acidification system simulated current and projected future environmental conditions. As expected, an increase in partial pressure of CO2, total inorganic carbon, bicarbonate ion, and CO2 resulted in more acidic pH levels, with the reverse being true for the carbonate ion. Structural changes of MPs were evaluated, revealing that all weathered samples underwent higher degradation rate compared to the virgin samples. The oxidation state and crystallinity of PP and EVA MPs were higher in samples exposed to the lowest pH, whereas no significant increase in the degradation rate of EPS samples was observed. Saltwater acidification in this study contributed to enhance the photo-oxidation of MPs depending on their polymeric composition., Competing Interests: Declaration of competing interest The authors have no relevant financial or non-financial interests to disclose. Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study identified the occurrence of Holocene chronology hiatuses in the sedimentary record of the Patos-Mirim system caused by river avulsion processes, as well as evidence of sharp anthropogenic changes in the surrounding region of the lagoon water bodies. The presence of chronology hiatuses demonstrates the importance of considering the disturbance effect of paleo-drainage processes on the paleoenvironmental resolution and expression of the sedimentary record of such coastal plains. Anthropogenic activities especially those related to agriculture and forestry have increased significantly during the great acceleration, resulting in modifications of both the landscape and the environmental conditions of the lagoon bodies. Such impacts were clearly reflected in the sedimentary record where abrupt changes in palynological trends, sedimentary DNA, isotopic and granulometric analyses were inferred. The climatic conditions combined with regressive sea level can explain the chronology hiatuses. Pollen analyses demonstrated changes in the landscape, particularly indicated by the shift from Cyperaceae to Poaceae dominance after the 1960 CE. Therefore, all proxies together demonstrate the modification in the landscape and changes in the environment, clearly influenced by anthropogenic action from unsustainable agricultural practices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Under two detection schemes, this study analyzes one of the most destructive weather systems - the explosive cyclones - in the South Atlantic, from 2010 to 2020. Then, two methods are presented to study these systems: the Observational Method (OBSM) and the Automated Method (AUTM). The first uses visual analysis of the mean sea level pressure (mslp) fields and functions to identify the local minimums using the Grid Analysis and Display (GrADS) software. The second utilizes a function from OpenGrADS called mfhilo. It shows the local minimum in the grid using laplacian, magnitude, and percentile. Two shell algorithms for data manipulation are used for the AUTM: one to trace the cyclones' trajectories according to a previously defined fixed area and the other to separate them into explosives. The OBSM methodology showed 271 cases averaging 25 yearly and revealed important characteristics regarding the intensities. According to AUTM's methodology, from the 2705 ordinary cyclone cases identified, 299 are explosives. There is a clear seasonality pattern in the systems' distribution along South America, similar to OBSM, but more highlighted. In summer, they concentrate at high latitudes, while in winter and spring, they are assembled near southern Brazilian and Uruguayan coasts.

Organotin compounds (OTs) are well studied in various environmental compartments, with a critical focus on the water column as their primary entry point into aquatic ecosystems. In this context, a method for the analysis of organotin (OTs) in water using silicone rubber-based passive sampling was optimized, validated, and field-tested. Validation covered crucial parameters, including the limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, linearity, and matrix effect. The method was shown to be robust (R 2  ≥ 0.99), with recoveries between 70.2 and 114.6%, and precise (CV < 12.8%) (N = 3). LOD Cw and LOQ Cw were ≤15 and ≤ 48 pg Sn L -1 , respectively, for TBT and TPhT. The matrix effect showed to be low (>-20% ME < 20%) for all OTs but TPhT (69.4%). The silicone rubber-water partition coefficients (Log K sr,w ) were estimated at 3.37 for MBT, 3.77 for DBT, 4.17 for TBT, 3.49 for MPhT, 3.83 for DPhT, and 4.22 for TPhT. During the field study carried out between October 2021 and February 2022 at the entrance of the Port of Santos navigation channel (Southeastern Brazil), sampling rates ranged between 4.1 and 4.6 L d -1 , and the equilibrium was achieved for MBT, DBT, MPhT, and DPhT after ∼45 days of deployment. The freely dissolved concentrations varied between 134 and 165 pg Sn L -1 for TBT, 388 and 610 pg Sn L -1 for DBT, and 1114 and 1509 pg Sn L -1 for MBT, while MPhT, DPhT, and TPhT were below the limit of detection. Results pointed out that J-FLEX® rubber-based passive sampling is a suitable and reliable alternative method for the continuous monitoring of OTs in the water column., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Gilberto Fillmann reports financial support was provided by National Council for Scientific and Technological Development. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The present study investigated the best photoperiod for culturing pacu (Piaractus mesopotamicus) in recirculation aquaculture systems (RAS) based on its growth performance and hematological and oxidative stress responses. Juveniles (∼ 5 g) were subjected to five treatments (in triplicate): 24 L (light):0D (dark), 15 L: 09D, 12 L:12D, 9 L:15D, and 0 L:24D for 45 days. A total of 225 pacu individuals were randomly distributed among 15 tanks of 210 L (n = 15 per tank). Zootechnical, hematological (glucose, lactate, hematocrit, and hemoglobin), and antioxidant and oxidative stress parameters (glutathione S-transferase (GST), total antioxidant capacity against peroxyl radicals (ACAP), and lipid peroxidation (LPO) were analyzed. The zootechnical parameters (e.g., weight gain, Fulton's condition factor, and specific growth rate) were better and worse with 9 L:15D and 24 L:0D photoperiods, respectively. The hepatosomatic index was higher and lower in the 0 L:24D and 9 L:15D photoperiods. Blood lactate levels and antioxidant and oxidative stress responses were increased in the longest photoperiods (15 L:9D and 24 L:0D). In contrast, the treatments that showed lower oxidative damage (liver, gills, brain, and muscle) were 9 L:15D and 12 L:12D. In conclusion, manipulating artificial light is one way to improve fish growth and health, where the best photoperiod for pacu farming in RAS is 9 L:15D., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

We describe the seldom observed event of a group of type A killer whale (Orcinus orca) predating on an Antarctic minke whale (Balaenoptera bonaerensis) in austral summer 2019. A pod of 11-13 individuals was observed - and documented by photographs and video - as they killed and fed on the minke whale in the Bransfield Strait, northern Antarctic Peninsula. The pod was being observed for about one hour, when some killer whale's individuals were noticed to be performing hunting behaviour. This lasted about 10 minutes, at the end of which the minke whale was killed. Three different species of seabirds were observed feeding on the minke carcass. A video of the encounter is provided.

Polycyclic aromatic hydrocarbons (PAHs), released from petrogenic, pyrogenic or diagenetic sources (degradation of wood materials), are of global concern due to their adverse effects, and potential for long-range transport. While dissolved PAHs have been frequently reported in the literature, there has been no consistent approach of sampling across water bodies. Passive samplers from the AQUA/GAPS-MONET initiative were deployed at 46 sites (28 marine and 18 freshwater), and analyzed for 28 PAHs and six polycyclic musks (PCMs) centrally. Freely dissolved PAH concentrations were dominated by phenanthrene (mean concentration 1500 pg L -1 ; median 530 pg L -1 ) and other low molecular weight compounds. Greatest concentrations of phenanthrene, fluoranthene, and pyrene were typically from the same sites, mostly in Europe and North America. Of the PCMs, only galaxolide (72% of samples) and tonalide (61%) were regularly detected, and were significantly cross-correlated. Benchmarking of PAHs relative to penta- and hexachlorobenzene confirmed that the most remote sites (Arctic, Antarctic, and mountain lakes) displayed below average PAH concentrations. Concentrations of 11 of 28 PAHs, galaxolide and tonalide were positively correlated ( P < 0.05) with population density within a radius of 5 km of the sampling site. Characteristic PAH ratios gave conflicting results, likely reflecting multiple PAH sources and postemission changes.

This review summarizes the state of knowledge on athecate dinoflagellates occurring within the South Atlantic Ocean and Atlantic sector of the Southern Ocean. We compiled data from 105 articles and selected 33 addressing any aspect of athecate dinoflagellate studies. Our aim is to discuss the patterns in athecate dinoflagellate distribution by building a thorough species list and an occurrence map based on species recorded in coastal and oceanic waters. We found 69 species totaling 141 occurrences in the entire South Atlantic Ocean basin. Contradicting global trends, most species distributed throughout this region are subtropical. We linked this trend to a higher local effort in dinoflagellate research instead of higher biodiversity, especially when compared to usual hotspots in biodiversity attributed to tropical oceans. The Subantarctic and Antarctic regions had a low number of occurrences, with 12 and 5, respectively. Except for the occurrence of Gyrodinium lachryma in the Antarctic Zone, all records are unique, poorly described and never recorded again for species such as Gymnodinium baccatum and Gymnodinium antarcticum. This demonstrates that the state of knowledge regarding athecate dinoflagellates in the South Atlantic and especially in the Antarctic region is still limited due to a lack of directed investigation.

This work investigated the annual variations in dry snow (DSRZ) and wet snow radar zones (WSRZ) in the north of the Antarctic Peninsula between 2015-2023. A specific code for snow zone detection on Sentinel-1 images was created on Google Earth Engine by combining the CryoSat-2 digital elevation model and air temperature data from ERA5. Regions with backscatter coefficients (σ⁰) values exceeding -6.5 dB were considered the extent of surface melt occurrence, and the dry snow line was considered to coincide with the -11 °C isotherm of the average annual air temperature. The annual variation in WSRZ exhibited moderate correlations with annual average air temperature, total precipitation, and the sum of annual degree-days. However, statistical tests indicated low determination coefficients and no significant trend values in DSRZ behavior with atmospheric variables. The results of reducing DSRZ area for 2019/2020 and 2020/2021 compared to 2018/2018 indicated the upward in dry zone line in this AP region. The methodology demonstrated its efficacy for both quantitative and qualitative analyses of data obtained in digital processing environments, allowing for the large-scale spatial and temporal variations monitoring and for the understanding changes in glacier mass loss.

The blue shark is a highly migratory species with a worldwide distribution, making it susceptible to multiple fishing fleets across the globe. In southern Brazil, it is an important target, comprising up to 40% of the total biomass landed by the commercial surface longline fleet. This study aims to contribute to a better understanding of how the species uses the region and to update its life-history information available for future assessments. Over five consecutive years (2018-2022) of landings and onboard monitoring, we gathered size data and vertebral samples to describe the species size composition in the region, as well as its seasonal and interannual variability and to update estimated life-history parameters. The results showed that southern Brazil is mainly inhabited by large juvenile males that arrive during winter (July-September) and stay until spring (October-December), when their frequency decreases. Small adult males are present throughout the year but in higher frequencies during summer. A small number of adult females are present with higher frequencies during spring and summer, which decreases during the austral autumn and winter. Some variability in the presence of each life stage was observed among years. The estimated life-history parameters were as follows: L∞: 255.02 cm fork length (FL), k: 0.20, L 0 :35.68 cm FL for males; L∞: 246.47 cm FL, k: 0.23, L 0 :36.77 cm FL for females; and L∞: 269.58 cm FL, k: 0.18, L 0 :36.19 cm FL for pooled sexes. However, the estimated values must be cautiously interpreted, as the obtained samples cannot be construed as representative of the entire harvested stock due to the lack of consistent presence of some life stages in the study region., (© 2024 Fisheries Society of the British Isles.)

Mercury contamination has been aggravated by emerging environmental issues, such as climate change. Top predators present concerning Hg concentrations once this metal bioaccumulates and biomagnifies. This study evaluated total mercury (THg) concentrations in tissues of 43 franciscanas (Pontoporia blainvillei) from two populations: the Franciscana Management Area (FMA) IIb and FMA IIIa. Animals from FMA IIIa showed mean concentration 5-times and 2.5-times higher in the liver and kidney (4.73 ± 6.84 and 0.52 ± 0.51 µg.g -1 , w.w., respectively) than individuals from FMA IIb (0.89 ± 1.04 and 0.22 ± 0.15 µg.g -1 , w.w., respectively). This might be due to: (I) individuals sampled from FMA IIIa being larger and older, and/or (II) the area near FMA IIIa presents environmental features leading to higher THg availability. Coastal contamination can affect franciscanas' health and population maintenance at different levels depending on their life history and, therefore, it should be considered to guide specific conservation actions., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds ubiquitous in the environment and known for their toxic, mutagenic, and carcinogenic effects. These compounds can bioaccumulate in the biota and be transferred through trophic webs. The franciscana dolphin (Pontoporia blainvillei), as top predators, can be an environmental sentinels. Thus, this study aimed to provide data about PAHs concentration in their hepatic tissue collected on the coast of Espírito Santo (Franciscana Management Area, FMA Ia), Rio de Janeiro (FMA IIa), and São Paulo states (FMA IIb), in Southeastern Brazil. PAHs were detected in 86 % of franciscana dolphins (n = 50). The highest ∑PAHs Total median concentration was reported in FMA Ia followed by FMA IIb and FMA IIa (1055.6; 523.9, and 72.1 ng.g -1 lipid weight, respectively). Phenanthrene was detected in one fetus and two neonates, showing maternal transfer of PAHs in these dolphins. Evaluating PAHs with potential toxic effects is of utmost importance for the conservation of a threatened species., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Cilia are widely present in metazoans and have various sensory and motor functions, including collection of particles through feeding currents in suspensivorous animals. Suspended particles occur at low densities and are too small to be captured individually, and therefore must be concentrated. Animals that feed on these particles have developed different mechanisms to encounter and capture their food. These mechanisms occur in three phases: (i) encounter; (ii) capture; and (iii) particle handling, which occurs by means of a cilia-generated current or the movement of capturing structures (e.g. tentacles) that transport the particle to the mouth. Cilia may be involved in any of these phases. Some cnidarians, as do other suspensivorous animals, utilise cilia in their feeding mechanisms. However, few studies have considered ciliary flow when examining the biomechanics of cnidarian feeding. Anthozoans (sessile cnidarians) are known to possess flow-promoting cilia, but these are absent in medusae. The traditional view is that jellyfish capture prey only by means of nematocysts (stinging structures) and mucus, and do not possess cilia that collect suspended particles. Herein, we first provide an overview of suspension feeding in invertebrates, and then critically analyse the presence, distribution, and function of cilia in the Cnidaria (mainly Medusozoa), with a focus on particle collection (suspension feeding). We analyse the different mechanisms of suspension feeding and sort them according to our proposed classification framework. We present a scheme for the phases of pelagic jellyfish suspension feeding based on this classification. There is evidence that cilia create currents but act only in phases 1 and 3 of suspension feeding in medusozoans. Research suggests that some scyphomedusae must exploit other nutritional sources besides prey captured by nematocysts and mucus, since the resources provided by this diet alone are insufficient to meet their energy requirements. Therefore, smaller particles and prey may be captured through other phase-2 mechanisms that could involve ciliary currents. We hypothesise that medusae, besides capturing prey by nematocysts (present in the tentacles and oral arms), also capture small particles with their cilia, therefore expanding their trophic niche and suggesting reinterpretation of the trophic role of medusoid cnidarians as exclusively plankton predators. We suggest further study of particle collection by ciliary action and its influence on the biomechanics of jellyfishes, to expand our understanding of the ecology of this group., (© 2024 Cambridge Philosophical Society.)

Estuarine mangroves are often considered nurseries for the Atlantic Goliath grouper juveniles. Yet, the contributions of different estuarine primary producers and habitats as sources of organic matter during early ontogenetic development remain unclear. Given the species' critically endangered status and protection in Brazil, obtaining biological samples from recently settled recruits in estuaries is challenging. In this study, we leveraged a local partnership with fishers and used stable isotope (C and N) profiles from the eye lenses of stranded individuals or incidentally caught by fishery to reconstruct the trophic and habitat changes of small juveniles. The eye lens grows by the apposition of protein-rich layers. Once these layers are formed, they become inert, allowing to make inferences on the trophic ecology and habitat use along the development of the individual until its capture. We used correlations between fish size and the entire eye lens size, along with estuarine baselines, to reconstruct the fish size and trophic positions for each of the lens layers obtained. We then used dominant primary producers and basal sources from mangrove sheltered, exposed estuarine and marine habitats to construct an ontogenetic model of trophic and habitat support changes since maternal origins. Our model revealed marine support before the juveniles reached 25 mm (standard length), followed by a rapid increase in reliance on mangrove sheltered sources, coinciding with the expected size at settlement. After reaching 60 mm, individuals began to show variability. Some remained primarily supported by the mangrove sheltered area, while others shifted to rely more on the exposed estuarine area around 150 mm. Our findings indicate that while mangroves are critical for settlement, as Goliath grouper juveniles grow, they can utilize organic matter produced throughout the estuary. This underscores the need for conservation strategies that focus on seascape connectivity, as protecting just one discrete habitat may not be sufficient to preserve this endangered species and safeguard its ecosystem functions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

It is commonly assumed that beach seining (BS) is more sustainable than bottom trawling because it involves non-motorized operations and limited fishing power. However, no scientific evidence supports this assumption. To address this gap, we evaluated the impact of beach seining, taking a small-scale shrimp fishery in northeast Brazil. Data collected monthly from December 2016 to November 2017 and in literature, were assessed (BS 31,001 individuals, 119 species, 37 families, and 19 orders; BT 6,031 individuals, 58 species, 20 families, and 14 orders). Beach seining demonstrated a lower proportion of bycatch (BS 1:2.3; BT 1:3.2), higher total shrimp catch (BS 87.2 t; BT 65 t), and greater species diversity than bottom trawling catches (BS 119; BT 58). Other aspects were closer associated with bottom trawling, such as the composition of dominant families (Sciaenidae and Pristigasteridae), the proportion of rare species (BS 30%; BT 24%) juveniles (BS 11g; BT 13g), the risk of species extinction, and the composition of ecological guilds. Despite their social significance, both fishing gears showed similar ecological indicators and adverse effects. The findings establish that the ecological concerns related to the impact of bottom trawling are also applicable to beach seine.

Monitoring of contaminant levels in wildlife over time is a tool for assessing the presence and persistence of environmental impacts at ecosystem, community and population levels. Tropical seabirds breeding in the Abrolhos Archipelago, 70 km off the Brazilian coast, forage in areas under the influence of the Doce River discharge. In 2015, the Fundão Dam collapsed and released ca 60 million tons of iron ore tailings into the ocean. In the present study, red-billed tropicbirds Phaethon aethereus and brown boobies Sula leucogaster breeding in Abrolhos were monitored over four years (2019-2022) for metal (Fe, Mn, Zn, Cu, Cr, Hg, Pb, Cd) and metalloid (As) concentrations in blood and feathers. Over six sampling events, metal (loid) concentrations showed strong temporal variation in both tissues. Overall, feathers showed greater element concentrations than blood, with stronger correlations between elements, especially Mn and the nonessential As, Cd, Hg and Pb. Mn is one of the major chemical markers of the Fundão Dam tailings. Metal (loid) concentrations in the tropical seabirds evaluated were above suggested threshold levels for most nonessential elements (As, Cd and Pb), especially in February 2021, when metal (loid) concentrations peaked in feathers. In this case, values were orders of magnitude higher than those observed in other sampling events. This occurred one year after a major rainy season in the Doce River basin, which increased river discharge of contaminated mud into the ocean, where contaminants are further remobilized by winds and currents, resulting in transference through the marine food web. This finding is consistent to what has been observed for other ecosystem compartments monitored in the region under the influence of the Doce River. Our findings highlight the utility of using tropical seabirds as sentinels of marine pollution, revealing strong temporal patterns in metal (loid) concentrations associated to bottom-up climatic processes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Litter pollution is a growing concern, including for Antarctica and the species that inhabit this ecosystem. In this study, we investigated the microplastic contamination in three seal species that inhabit the Western Antarctic Peninsula: crabeater (Lobodon carcinophaga), leopard (Hydrurga leptonyx) and Weddell (Leptonychotes weddellii) seals. Given the worldwide ubiquity of this type of contaminant, including the Southern Ocean, we hypothesized that the three seal species would present anthropogenic debris in their feces. We examined 29 scat samples of crabeater (n = 5), leopard (n = 13) and Weddell (n = 11) seals. The chemical composition of the items found were identified using micro-Raman and micro-FTIR spectroscopies. All the samples of the three species presented anthropic particles (frequency of occurrence - %FO - 100 %). Fibers were the predominant debris, but fragments and filaments were also present. Particles smaller than 5 mm (micro debris) were predominant in all the samples. Leopard seals ingested significantly larger micro-debris in comparison with the other seal species. The dominant color was black followed by blue and white. Micro-Raman and micro-FTIR Spectroscopies revealed the presence of different anthropogenic pigments such as reactive blue 238, Indigo 3600 and copper phthalocyanine (blue and green). Carbon black was also detected in the samples, as well as plastic polymers such as polystyrene, polyester and polyethylene terephthalate (PET), polyamide, polypropylene and polyurethane These results confirm the presence of anthropogenic contamination in Antarctic seals and highlight the need for actions to mitigate the effects and reduce the contribution of debris in the Antarctic ecosystem., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Julieta Denise Cebuhar reports financial support was provided by Society for Marine Mammalogy. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier B.V.)

Microplastic pollution is becoming a continuously growing environmental concern, while bivalve mollusks are particularly vulnerable due to their sessile habits and feeding through water filtration processes. Microplastic incidence in soft tissues of the clam Amarilladesma mactroides was assessed along unconsolidated substrates distributed in extensive coastal regions of southern Brazil. Influence of urbanization levels, distance to rivers and local hydrodynamics on microplastic accumulation by the clam was tested. The average concentration of microplastics was high (3.09 ± 2.11 particles.g -1 ), considering 16 sampled sites. Particles were mainly composed by polyamide, polyethylene and polyethylene terephthalate, while were mainly smaller, fibrous and colorless. High urbanization and closer proximity to rivers insured higher contamination, which is a trend observed globally. No influence of coastal hydrodynamics was seen. Considering obtained findings, A. mactroides presents good potential to be used as a valuable tool to assess microplastic contamination in unconsolidated substrates of beach areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Weather radiosondes play a crucial role in gathering atmospheric data for weather modeling and forecasting. However, their impact on marine wildlife, particularly seabirds, has raised concerns regarding the potential threats posed by these instruments. This study aims to assess the adverse effects of weather balloons on albatrosses, with a focus on the Southwest Atlantic region. The research reveals seven cases of entanglement of radiosonde equipment, leading to severe injuries and mortality along the Southern and Southeastern coasts of Brazil. Recommendations for mitigating the environmental impact of weather balloons include the adoption of biodegradable materials in their design and the implementation of improved retrieval protocols. Furthermore, the study stresses the importance of continued monitoring and research to address the interaction of weather radiosondes with marine animals. This approach is vital for ensuring the sustainable collection of scientific data while minimizing harm to marine life and ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Anxiety is among the most prevalent mental disorders present in the general population. Benzodiazepines are the most commonly prescribed drugs for the treatment of anxiety. Using zebrafish as a model organism, we investigated the anxiolytic activity of JM-20, a novel hybrid molecule with a 1,5-benzodiazepine ring fused to a dihydropyridine moiety. Firstly, we carried out some assays to analyze the possible toxicity mediated by JM-20. For this, zebrafish were exposed to different JM-20 concentrations (0-5 μM) for 96 h. Then, using the novel tank test, we evaluated both locomotor and anxiety-like behavior of the animals. Furthermore, brain, liver and plasma were removed to assess toxicity parameters. JM-20 exposure did not cause changes on novel tank, and also did not alter brain viability, hepatic LDH and plasma ALT levels. Afterward, we investigated whether a pre-exposure to JM-20 would prevent the anxiogenic effect evoked by caffeine. In the novel tank test, caffeine significantly decreased the time spent at the top, as well as the number of transitions to the top area. Moreover, caffeine decreased both the total and average time spent in the lit area, as well as increased the number of risk episodes evaluated by the light-dark test. Whole-body cortisol levels were also increased by caffeine exposure. Interestingly, pre-treatment with JM-20 abolished all alterations induced by caffeine. The anxiolytic effect profile of JM-20 was similar to those found for diazepam (positive control). Our findings show, for the first time, the anxiolytic effect of JM-20 in zebrafish, and its relationship with cortisol regulation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Cu is a vital micronutrient, but free Cu ions (Cu 2+ ) in seawater, even at subnanomolar concentrations, can impede phytoplankton growth. Natural Cu complexation with organic ligands regulates Cu acquisition and, in most instances, reduces Cu 2+ concentrations below toxic thresholds. Along the Antarctic coast, the sources and sinks of Cu and its associated ligands remain poorly defined. Despite the high productivity in the area, there are no studies on the role of trophic transfer in Cu cycling. This study explores penguin guano release of Cu and Cu ligands and its potential in neutralizing copper toxicity along the Antarctic coast. We collected guano in a Chinstrap penguin nesting location in the West coast of Deception Island and extracted its components into aqueous solution imitating natural processes. Copper concentration in guano was 0.4 mg (dry weight g) -1 constituting a potential toxic threat and showed biomagnification with respect to krill. Surface seawater samples collected from various locations varying in penguin activity, were analyzed to assess the potential influence of guano on the area. Visual examination and elevated levels of Al suggested that a substantial portion of guano was lithogenic. Consequently, only a modest 16 % of the total Cu present in guano could be extracted using mechanical methods. Notably, the concentrations of the extracted organic ligands were approximately 23 times higher than the concentrations of the extracted Cu. This significant presence of ligands effectively nullifies any potential toxicity that could have arisen from free Cu 2+ ions. Guano ligands' conditional stability constants were lower than those in surface seawater suggesting phytoplankton exudation was the main ligand source in the area. Overall, guano acts as a key node for Cu cycling in coastal Antarctic waters but its deleterious potential is neutralized by ligands from krill digestion and the high background concentration of phytoplankton exudates., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Daniel Garcia-Veira reports financial support was provided by Government of the Balearic Islands. Office of European Funds, University and Culture., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Rhizostomeae species attract our attention because of their distinctive body shape, their large size and because of blooms of some species in coastal areas around the world. The impacts of these blooms on human activities, and the interest in consumable species and those of biotechnological value have led to a significant expansion of research into the physiology and functional biology of Rhizostomeae jellyfish over the last years. This review brings together information generated over these last decades on rhizostome body composition, locomotion, toxins, nutrition, respiration, growth, among other functional parameters. Rhizostomes have more than double the carbon content per unit of biomass than jellyfish of Semaeostomeae. They swim about twice as fast, and consume more oxygen than other scyphozoans of the same size. Rhizostomes also have faster initial growth in laboratory and the highest body growth rates measured in nature, when compared to other medusae groups. Parameters such as body composition, nutrition and excretion are highly influenced by the presence of symbiotic zooxanthellae in species of the Kolpophorae suborder. These physiological and functional characteristics may reveal a wide range of adaptive responses, but our conclusions are still based on studies of a limited number of species. Available data indicates that Rhizosotomeae jellyfish have a higher energy demand and higher body productivity when compared to other jellyfish groups. The information gathered here can help ecologists better understand and make more assertive predictions on the role of these jellyfish in their ecosystems., (Copyright © 2024. Published by Elsevier Ltd.)

Rhizostomeae research based on morphological approaches was reinforced and diversified by new techniques after the 1970s, including developing methodologies for phylogenetic analysis, the rise of the polymerase chain reaction, and the emergence of different sequencing technologies. Here, we summarize the contribution of morphological and molecular data to the study of the classification and phylogenetic relationships of Rhizostomeae in addition to the use of molecular data in studies at the population, species, and supraspecific levels. Throughout the history of the study of the Rhizostomeae systematics, morphological data have been neglected when it comes to phylogenetic inferences, which is reflected in the lack of a phylogenetic analysis of the taxa within Rhizostomeae based on phenotypic characters of the adult medusa. Concerning molecular data, ca. 3,200 nucleotide sequences are available in GenBank and are mainly used for discovering, delimiting, describing, and identifying species. Molecular approaches have also allowed species monitoring by qPCR and metabarcoding of environmental DNA, as well as unveiling the distribution and genetic diversity of jellyfish populations, shedding light on introduction events, conservation, and health of edible jellyfish stocks. Nucleotide sequences have also been key for the development of phylogenetic hypotheses that serve as basis for investigations on the origin and diversification of morphological, ecological, and behavioral traits within Cnidaria; however, despite the progress achieved, phylogenetic uncertainty still exists, especially within the formerly known superfamily Inscapulatae. Future directions in Rhizostomeae research involve generating molecular and morphological data of neglected taxa, which represents a golden opportunity to understand the evolution of Rhizostomeae., (Copyright © 2024. Published by Elsevier Ltd.)

The objective of this investigation is to evaluate the recent changes in the accumulation of organic matter and carbon on the Yahuarcaca lake system, by means of a multiproxy paleolimnological study. The methodology based on lithological descriptions of 210 Pb/ 137 Cs-dated cores allowed us to infer the centennial sedimentation processes and carbon accumulation rates. Sedimentary facies, grain size, magnetic susceptibility, loss on ignition, carbonate, chlorophyll derivatives, stable isotopes of δ 13 C/δ 15 N, and carbon accumulation rate were analyzed. LANDSAT and photographic record of satellite images were used to reconstruct the historical geomorphological evolution of the Lake. Sediment cores yielded basal ages of 1827 and 1828 Common Era, representing the formation of lakes as a consequence of the Amazon meandering process. Two main paleolimnological stages were identified, with a boundary transition set at 1980-1984 Common Era, attributed to the geomorphological closure and complete lake separation from the Amazon and the onset of full lentic conditions. This inference was mainly based on both sharp increases in the sedimentation rate from 0.2 to >1 cm yr -1 and carbon accumulation that increased seven-fold (from 2 to 14 g m- 2  yr -1 ) from 1980 to 1984 Common Era. The flood-pulse and connection to the Amazon defined the magnitude of organic inputs, where areas more distant/isolated from the river showed higher accumulation of carbon from autochthonous production, with an average of 8.9 % and 1.10 g m -2  yr -1 (carbon accumulation rate). Those areas closer and connected to the river were strongly related to the interannual hydrological variability, with a lower mean carbon content (5.9 %) and 0.73 g m -2  yr -1 (carbon accumulation rate). We concluded that carbon burial was highest within the most distant spot from the Amazon River because of the weaker connection to the river itself and the more stable lentic conditions for net sedimentation., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Using data from SCAR observations, ERA5 reanalysis, and regional climate model simulations (RACMO), we examined the influence of large- and regional-scale climate forcing on temperature and precipitation variations in the South Shetland Islands (SSI). Specifically, we focused on understanding how regional climate indices influence the temporal variability of temperature and precipitation on the SSI. Our findings indicate that both large- and regional-scale climate indices significantly impact the interannual and seasonal temperature variability in the SSI. For instance, the Amundsen Sea Low, characterised by low-pressure systems over the Amundsen Sea, and sea ice extent in the northwestern part of the Weddell Sea, exert a strong influence on temperature variability (r from -0.64 to -0.87; p < 0.05). In contrast, precipitation variability in this region is primarily controlled by regional climatic indices. Particularly, anomalies in atmospheric and surface pressure over the Drake Passage region strongly regulate the interannual variability of precipitation in the SSI (r from -0.46 to -0.70; p < 0.05). Large-scale climatic indices demonstrate low but statistically significant correlations, including the Southern Annular Mode and deep convection in the central tropical Pacific. Given the importance of temperature and precipitation in the glacier changes, we recommend assessing the impact of the Drake region on SSI glaciers.