Search Results (211)

Sediments are key players in the optimum functioning of ecosystems; however, they also represent the largest known repository of harmful contaminants. The vast variety of these sediment-associated contaminants may exert harmful effects on marine communities and can impair ecosystem functioning. Whole-cell biosensors are a rapid and biologically relevant tool for assessing environmental toxicity. Therefore, in this study, we developed a bioassay-based toxicity measurement system using genetically modified bacteria to create a whole-cell optical biosensor. Briefly, reporter bacteria were integrated and immobilized using a calcium alginate matrix on fiber-optic tips connected to a photon counter placed inside a light-proof, portable case. The calcium alginate matrix acts as a semi-permeable membrane that protects the reporter-encapsulated optical fiber tips and allows the inward passage of toxicant(s) to induce a dose-dependent response in the bioreporter. The samples were tested by directly submerging the fiber tip with immobilized bacteria into vials containing either water or suspended sediment samples, and the subsequent bioluminescent responses were acquired. In addition to bioavailable sediment toxicity assessments, conventional chemical methods, such as liquid chromatography–mass spectroscopy (LC-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES), were used for comprehensive evaluation. The results demonstrated the efficacy of the biosensor in detecting various toxicity levels corresponding to identified contaminants, highlighting its potential integration into environmental monitoring frameworks for enhanced sediment and water quality assessments. Despite its utility, this study notes the system’s operational challenges in field conditions, recommending future enhancements for improved portability and usability in remote locations. Full article

Exercise-induced muscle damage (EIMD) initiates an inflammatory response that is essential for tissue repair. However, when prolonged or excessive, this response can impair recovery and muscular performance. Specialized pro-resolving mediators (SPMs), derived from the metabolism of omega-3 (n-3) polyunsaturated fatty acids (PUFAs), facilitate the resolution of inflammation without causing immunosuppression. Evidence from preclinical studies indicates that SPM administration accelerates muscle repair and functional recovery by enhancing the clearance of apoptotic cells, suppressing pro-inflammatory signaling and modulating macrophage polarization. However, translation to human applications remains limited as commercially available SPM-enriched marine oils do not contain active SPMs but rather their monohydroxylated precursors, including 14-Hydroxy-Docosahexaenoic Acid (14-HDHA), 17-Hydroxy-Docosahexaenoic Acid (17-HDHA), and 18-Hydroxy-Eicosapentaenoic Acid (18-HEPE) in addition to low doses of the n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Furthermore, the variable increases in circulating SPM concentrations as a result of dietary intake of EPA and DHA, whether from fish or fish oil supplements, and the wide diversity of SPM molecules (many of which remain under investigation), highlight the complexity of their structural and functional networks. While advances in lipidomics have identified SPMs and their pathway intermediates in human biological samples, further research is needed to determine optimal dosing strategies, delivery mechanisms, and the real impact of SPM-enriched marine oil on athletic performance and recovery. This narrative review examines the biological rationale and current evidence surrounding SPM-enriched marine oil supplementation and its potential to enhance muscle recovery following EIMD. By synthesizing findings from preclinical and human studies, the potential of SPM-enriched supplementation as a novel tool for optimizing performance recovery in athletic populations is reviewed to inform future research directions. Full article

Mediterranean saline wetlands are significant ecological habitats defined by seasonal water availability and various biological communities, forming a unique ecotone that combines traits of both freshwater and marine environments. Moreover, they are regarded as notable natural and economic resources. Since the sustainable management of protected wetlands necessitates a multidisciplinary approach, the purpose of this study is to provide a comprehensive picture of the hydrological, hydrochemical, and ecological dynamics of a man-made groundwater dependent ecosystem (GDE) by combining remote sensing, hydrochemical data, geostatistical tools, and ecological indicators. The study area, called “Le Soglitelle”, is located in the Campania plain (Italy), which is close to the Domitian shoreline, covering a surface of 100 ha. The Normalized Difference Water Index (NDWI), a remote sensing-derived index sensitive to surface water presence, from Sentinel-2 was used to detect changes in the percentage of the wetland inundated area over time. Water samples were collected in four campaigns, and hydrochemical indexes were used to investigate the major hydrochemical seasonal processes occurring in the area. Geostatistical tools, such as principal component analysis (PCA) and independent component analysis (ICA), were used to identify the main hydrochemical processes. Moreover, faunal monitoring using waders was employed as an ecological indicator. Seasonal variation in the inundation area ranged from nearly 0% in summer to over 50% in winter, consistent with the severe climatic oscillations indicated by SPEI values. PCA and ICA explained over 78% of the total hydrochemical variability, confirming that the area’s geochemistry is mainly characterized by the saltwater sourced from the artesian wells that feed the wetland. The concentration of the major ions is regulated by two contrasting processes: evapoconcentration in summer and dilution and water mixing (between canals and ponds water) in winter. Cl⁻/Br⁻ molar ratio results corroborated this double seasonal trend. The base exchange index highlighted a salinization pathway for the wetland. Bird monitoring exhibited consistency with hydrochemical monitoring, as the seasonal distribution clearly reflects the dual behaviour of this area, which in turn augmented the biodiversity in this GDE. The integration of remote sensing data, multivariate geostatistical analysis, geochemical tools, and faunal indicators represents a novel interdisciplinary framework for assessing GDE seasonal dynamics, offering practical insights for wetland monitoring and management. Full article

The present study aimed to characterize the benthic macroinvertebrate community of the Jabal Ali Marine Sanctuary (JAMS), the sole marine protected area in the Emirate of Dubai, during the summer and winter seasons of 2017. Limited research on the biological quality of the JAMS prompted this investigation, which involved 10 sampling stations to assess macroinvertebrate diversity and community composition in relation to abiotic factors such as sediment granulometry, trace metals, salinity, and temperature. Collected sediment samples were analyzed for macroinfauna, and their abundance was measured, revealing an average abundance of 2150 ind/m² in summer and 2132 ind/m² in winter without a significant difference between both seasons. Univariate indices, including the Margalef diversity index and Pielou evenness index, indicate a range of diversity values across sampling sites. Community composition was assessed through SIMPROF and Bray–Curtis similarity clustering, further elucidating the relationship between community structures and environmental gradients. The dominant macroinvertebrate species varied across seasons and stations, providing insights into seasonal variations in community dynamics. These findings contribute to the understanding of benthic community structures and biodiversity in the JAMS and serve as a baseline for future monitoring and management efforts aimed at preserving the ecological integrity of this important marine sanctuary. Full article

The Southern Ocean, located between Antarctica and the southern tips of South America, Africa and Australia, encompasses an immense area across the southern Atlantic, Pacific and Indian oceans with no clearly defined limits. For the purposes of studying marine heterobranch sea slugs, we consider the Southern Ocean to include all ocean areas located south of latitude 41° S. South of this latitude, we consider different areas and zones: the area of South America (the Patagonia/Magellanic area), the island of Tasmania, the southern island of New Zealand, the Subantarctic area (the Falkland Islands, South Georgia Island, the South Orkney Islands, South Sandwich Island, Bouvet Island, the islands of Crozet and Prince Edward, the Kerguelen Islands, and Macquarie Island) and the area of Antarctica, in which we consider four zones (Weddell Sea, West Antarctica, Ross Sea and East Antarctica). Reviewing all available references and unpublished data from the authors, in total, 394 species of heterobranch sea slugs have been recorded to date in the Southern Ocean > 41° S, with Nudibranchia standing out with 209 species and Cephalaspidea with 90 species. The marine heterobranchs of Tasmania (154 species) and southern New Zealand (120 species) have been well studied. Sea slug fauna of the Antarctic and Subantarctic regions have been the subject of several partial studies; however, there are still many gaps in knowledge across both areas. Eighty-nine different species of sea slug have been recorded so far in strictly Antarctic waters (West Antarctica, 45 species; Weddell Sea, 48 species; Ross Sea, 51 species; East Antarctica, 42 species), while in the various Subantarctic regions, there are 93 species (36 species from South Georgia, 17 species from the South Orkneys, 12 species from south Sandwich, 6 species from Bouvet, 10 species from Prince Edward and Crozet Islands, 15 species from Kerguelen, 3 species from Macquarie Island, 29 species from the Falkland Islands and 71 species from the coast of South America). In the taxonomic section, for each of the species, the location and the authors of the records are indicated, and for many of the species, interesting biological, taxonomic or biogeographic observations are also provided. The importance of sampling in underexplored areas is discussed, as well as greater-depth sampling for a better understanding of the sea slugs of the Southern Ocean. Full article

Mariculture is currently experiencing rapid growth in response to the rising global food demand, while simultaneously posing significant challenges to environmental issues, such as pollution stress and ecological degradation. To achieve a balance between ecosystem maintenance and seafood supply, marine ranching has flourished as a sustainable approach through the implementation of artificial reef construction, stock enhancement, and strategic releasing. However, few studies have evaluated the ecological impacts through a comparison of in situ survey data across geographical areas. Phytoplankton are vital organisms in marine ecosystems that function as essential indicators of seawater quality and biological diversity, reflecting environmental health and ecological sustainability. In this study, we investigated the species diversity, community structure, and co-occurrence network of phytoplankton based on 175 samples collected from 75 sites encompassing all 26 marine ranching seawater areas, along with their corresponding surrounding areas in Yantai’s coastal sea. A total of 112 species were identified across three phyla of diatoms, dinoflagellates, and chrysophytes; among them, diatoms dominated the community with a notably high proportion of 98.83%. Their diversity and structure exhibited significant variations across different seasons and geographic locations. Moreover, no preference was observed between the marine ranching seawater and the surrounding areas. Nevertheless, a co-occurrence network analysis demonstrated that lower values for average degree, clustering coefficient, and average path length were exhibited in marine ranching, indicating that aquaculture activities have reduced connectivity among potential interactions. Additionally, it showed reduced stability as indicated by the remaining nodes and the natural connectivity indices, regardless of the proportion of nodes removed. These findings illustrate that while marine ranching processes can mitigate species losses with maintaining phytoplankton community structure, they still alter association among species and reduce overall stability. This research recommends that scientifically informed expansion of marine ranching necessitates robust environmental monitoring datasets and systematic validation to ensure holistic sustainability. Full article

The widespread use of recyclable materials in contemporary society has led to the accumulation of pollutants in estuaries and marine ecosystems, with potential impacts on biodiversity. This study assessed the abundance and types of particulate pollutants in Sphoeroides fish across two Brazilian estuaries (tropical and subtropical). Our findings showed that 70 biological samples from fish (92.11%) contained debris, with the tropical estuary exhibiting the highest abundance (n = 499 particles—67% of the total), dominated by laminar (film) particulate pollutants (76.75%). In this estuary, the gill exhibited the highest contamination index, with most particulate pollutants (<1 mm and 1–3 mm) found in 63.6% and 54.5% of samples, respectively. In the subtropical estuary, 246 debris particles (33% of the total) were detected in the biological samples, with 58.5% of particles being of the film type. The gastrointestinal tract had the highest contamination index in this region, with 70.6% of particles in the 1–3 mm size range. These results highlight the pervasive presence of particulate pollutants in estuarine ecosystems and the organ-specific contamination patterns in tropical and subtropical regions, underscoring the ecological risks posed by plastic waste to estuarine biodiversity in hotspot regions. Full article

Deep-sea biological detection is a pivotal technology for the exploration and conservation of marine resources. Nonetheless, the inherent complexities of the deep-sea environment, the scarcity of available deep-sea organism samples, and the significant refraction and scattering effects of underwater light collectively impose formidable challenges on the current detection algorithms. To address these issues, we propose an advanced deep-sea biometric identification framework based on an enhanced YOLOv8n architecture, termed PSVG-YOLOv8n. Specifically, our model integrates a highly efficient Partial Spatial Attention module immediately preceding the SPPF layer in the backbone, thereby facilitating the refined, localized feature extraction of deep-sea organisms. In the neck network, a Slim-Neck module (GSconv + VoVGSCSP) is incorporated to reduce the parameter count and model size while simultaneously augmenting the detection performance. Moreover, the introduction of a squeeze–excitation residual module (C2f_SENetV2), which leverages a multi-branch fully connected layer, further bolsters the network’s global representational capacity. Finally, an improved detection head synergistically fuses all the modules, yielding substantial enhancements in the overall accuracy. Experiments conducted on a dataset of deep-sea images acquired by the Jiaolong manned submersible indicate that the proposed PSVG-YOLOv8n model achieved a precision of 79.9%, an mAP50 of 67.2%, and an mAP50-95 of 50.9%. These performance metrics represent improvements of 1.2%, 2.3%, and 1.1%, respectively, over the baseline YOLOv8n model. The observed enhancements underscore the effectiveness of the proposed modifications in addressing the challenges associated with deep-sea organism detection, thereby providing a robust framework for accurate deep-sea biological identification. Full article

To achieve the aims of the Convention on Biological Diversity’s 2030 Global Biodiversity Framework, the management of marine areas requires the use of cost- and time- effective monitoring of biodiversity. Marine observation platforms are increasingly used for such monitoring activities. These platforms allow data to be collected from a variety of sensors simultaneously in real-time and in situ, providing the opportunity for both adapting where and when sampling is performed and for using multiple data streams for more comprehensive information to be collected on marine biodiversity. While some recent monitoring activities are following an adaptive sampling approach (in which sampling is adapted to ecological phenomena such as diel vertical migration), most still do not use a data-driven approach (in which multiple data streams are used to inform sampling). In this study, we performed eDNA metabarcoding to monitor the community of copepods found in the high-latitude environment near Trondheim, Norway. We applied an adaptive sampling approach to detect calanoid copepods at seasonally contrasting time points using real-time acoustic sensor data. Acoustic sensor data were used to inform when plankton net samples were collected in a 24 h period, as Calanoid copepods migrate through the water column throughout the day to avoid predation. These results demonstrate how multiple information streams from complimentary monitoring methods can be combined for more robust monitoring of biodiversity by confirming the presence (or absence) of relevant taxa. Full article

China is facing increasing marine microplastic pollution. Despite the fact that the South China Sea is the largest marine area in China, the ecological danger and present state of microplastic contamination in this region have not been systematically and comprehensively investigated. This study analyzed the abundance, distribution, and characteristics of microplastics in different environmental media and biological samples from the Xisha Islands in the South China Sea, and then the ecological risk assessment of microplastic pollution in this area was conducted. The findings indicated that the quantities of sediments, soil, water, fish, and birds were 41.56 ± 19.12 items/kg, 92.94 ± 111.05 items/kg, 2.89 ± 1.92 items/L, 2.57 ± 2.12 items/ind, and 1.702 ± 1.50 items/ind, respectively. By evaluating the pollution load index (PLI), polymer hazard index (PHI), and potential ecological risk index (PERI), the PLI of the Xisha Islands in the South China Sea as a whole indicated that the hazard level was slightly polluted, the PHI was at a high-risk level, and the PERI samples were at no risk, except for the soil and seawater, which were at a medium-risk level. Full article

Biomonitoring and environmental impact assessment of marine ecosystems are important for the effective management of petroleum platform activity. Eukaryote biodiversity in water and sediment near petroleum platforms in the Gulf of Thailand was surveyed using environmental DNA (eDNA) based on 18S ribosomal DNA variable region 4 (18S rDNA-V4), the full-length 18S rDNA gene (18S rDNA-FL), and cytochrome c oxidase subunit 1 (COI). Water and sediment samples were collected from three platforms. The water sample was also collected from a reference site located farther south, away from the platforms. Both 18S rDNA markers outperformed COI. A total of 1144 and 889 species were found in water and sediment when analyzed by 18S rDNA-V4, and 519 species were found in sediment when analyzed by 18S rDNA-FL. Only 99 species were found in water samples when analyzed by COI. Alpha-diversity (Shannon and Simpson Evenness) indices were significantly different in water (p < 0.05), but not in sediment (p > 0.05). Beta-diversity (PCoA and NDMS) revealed significant species components between different petroleum platforms (p < 0.01). Species distribution revealed biological connectivity between eukaryotes from different platforms suggesting the importance of platforms on ecological impacts. This study also illustrates the possible application of eDNA for monitoring ecological toxicity around petroleum platforms. Full article

The South China Sea is rich in cone snail resources, known for producing conotoxins with diverse biological activities such as analgesic, anticancer, and insecticidal effects. In this study, five vermivorous cone snail samples were collected from the South China Sea and their crude venom was extracted to investigate the variations in venom components and activities, aiming to identify highly active samples for further research. Cluster analysis using reverse-phase high-performance liquid chromatography (RP-HPLC) fingerprints and mitochondrial cytochrome c oxidase I (COI) gene sequences revealed that the diversity of venom components across different conotoxin species is genetically correlated. Activity assays demonstrated that all five cone snail venoms exhibited lethal effects on insects and zebrafish. Notably, the crude venom of Conus quercinus showed the highest insecticidal activity with an LD₅₀ of 0.6 μg/mg, while C. tessellatus venom exhibited the most potent zebrafish lethality with an LD₅₀ of 0.2 μg/mg. Furthermore, the crude venom from four cone snail species demonstrated toxicity against ovarian cancer cells, and only C. caracteristicu venom displayed significant analgesic activity. This study systematically identifies cone snail samples with promising insecticidal, anticancer, and analgesic properties, paving the way for the development and utilization of cone snail resources from the South China Sea and offering a novel approach for advancing marine peptide drug research. Full article

This study assessed the growth characteristics of Conger myriaster in large-scale floating raft aquaculture habitats and natural habitats. Monthly sampling in aquaculture and control areas, combined with biological and morphological data analyses, were used to investigate the growth, morphological differences, and seasonal distribution of Conger myriaster in different habitats. The results showed that the floating raft aquaculture habitat was dominated by juveniles, with a higher abundance compared to the control areas. The juveniles exhibited favorable levels of growth and ecological performance in the floating raft aquaculture habitat and experienced less environmental stress. This research shows that the floating raft aquaculture habitat provides a critical stage habitat for juvenile Conger myriaster in island reef areas, providing refuge from predation and facilitating juvenile development. The integration of surface floating rafts and bottom-set artificial reefs in marine ranching can create a fisheries model that focuses on the protection of juveniles and the exploitation of adults. Full article

Marine bacterioplankton perform a very important role in the cycles of carbon, nitrogen, phosphorus, and other elements in coastal waters. The impacts of environmental factors on bacterial community structure are dynamic and ongoing. This study investigated the spatiotemporal distributions of elements and their influences on bacterioplankton communities in the coastal waters around the Changli Gold Coast National Nature Reserve in northern China. The results demonstrate the significant temporal variability of phosphorus, nitrogen, and carbon in spring and summer, influenced by natural environmental factors and anthropogenic activities. In spring, increased biological activity, particularly phytoplankton growth, may elevate TOC and POC levels near the river estuaries, while in summer, microbial decomposition likely stabilized carbon concentrations. The seasonal variation in the bacterioplankton community was obvious. Bacteroidetes were enriched in spring samples and Cyanobacteriota proliferated in summer. The dominated genera in the spring, including Planktomarina, an unclassified NS5_marine_group (belonging to Flavobacteriaceae), and the OM43_clade (Methylophilaceae), showed significant positive correlation with salinity, TDP, TOC, POP, and DO levels, while Synechococcus_CC9902 (Synechococcus), PeM15_unclassified (Actinobacteria), and HIMB11 (Rhodobacteraceae), which all dominate in summer samples, are significantly positively correlated with TN, TDN, temperature, and ammonium levels. In summer in particular, the increase in human activities and river inputs greatly improves nutrient levels and promotes the propagation of photosynthetic microorganisms. These results indicate that the nutrient elements and environmental physical conditions are affected by seasonal changes and human activities, which have significant effects on the community structure of bacterioplankton. This study highlights the importance of ongoing monitoring in estuarine coastal areas, especially in protected areas like the Changli Reserve, to manage eutrophication risks and maintain ecological balance. Full article

Some marine and extremophilic microorganisms are capable of synthesizing sulfated polysaccharides with a unique structure. A number of studies indicate significant biological properties of individual sulfated polysaccharides, such as antiproliferative activity, which makes them a promising area for further research. In this study, the capsular polysaccharide (CPS) was obtained from the bacterium Cobetia marina KMM 1449, isolated from a marine sediment sample collected along the shore of the Sea of Japan. The CPS was isolated by saline solution, purified by a series of chromatographic procedures, and studied by chemical methods along with 1D and 2D ¹H and ¹³C NMR spectroscopy. The following new structure of the CPS from C. marina KMM 1449 was established and consisted of sulfated and simultaneously phosphorylated disaccharide repeating units: →4)-α-L-Rhap2S-(1→3)-β-D-Manp6PGro-(1→. To elucidate the genetic basis of the CPS biosynthesis, the whole genomic sequence of C. marina KMM 1449 was obtained. The CPS biosynthetic gene cluster (BGC) of about 70 genes composes four regions encoding nucleotide sugar biosynthesis (dTDP-Rha and GDP-Man), assembly (GTs genes), translocation (ABC transporter genes), sulfation (PAPS biosynthesis and sulfotransferase genes) and lipid carrier biosynthesis (wcb operon). Comparative analysis of the CPS BGCs from available Cobetia genomes showed the presence of KMM 1449-like CPS BGC among strains of all three Cobetia species. The study of new natural sulfated polysaccharides, as well as the elucidation of the pathways of their biosynthesis, provides the basis for the development of potential anticancer drugs. Full article