Search Results (36)

The method of extracting energy from a fluid environment using flapping foils offers advantages such as structural simplicity and environmental friendliness. However, its low energy harvesting efficiency remains a significant factor limiting its development. This study employs suction and blower-based control (SBC) to enhance the energy harvesting efficiency of flapping foils. Using an orthogonal experimental design and numerical methods, 49 representative combinations of SBC geometries were selected for numerical simulation. The effects and priority rankings of geometric parameters on foil performance were statistically analyzed. It was found that under the optimal geometry (the suction slot position is 0.54c, the injection slot position is 0.79c, the width of the slot is 0.015c, the angle of the suction slot is −3°, and the angle of the injection slot is −9°), the energy harvesting efficiency can reach 40.7%. Furthermore, under laminar flow conditions, the benefit of SBC increases with higher Reynolds numbers (Re). At Re = 2200, SBC maximized the improvement in energy harvesting efficiency by 76%. No significant correlation was observed between the flapping amplitude and the SBC effect. However, the reduced frequency significantly influences the efficiency improvement generated by SBC. The SBC method shifts the foil’s optimal operating region towards lower reduced frequencies, which benefits energy harvesting efficiency. The research presented herein may have potential applications in the development of marine energy systems and bio-inspired propulsion. Full article

The expansion of global maritime activities threatens marine ecosystems and biodiversity. Collisions between ships and marine megafauna profoundly impact vulnerable species such as whales, who serve as keystone predators. However, the specific regions most heavily affected by shipping traffic and the multi-species facing collision risk remain poorly understood. Here, we analyzed global shipping data to assess the distribution of areas with high shipping pressure and identify global hotspots for whale–ship collisions. The results reveal that high-pressure habitats are primarily distributed within exclusive economic zones (EEZs), which are generally consistent with the distribution of collision hotspots. High-pressure habitats exhibit significant spatial mismatch: 32.9% of Marine Protected Areas endure high shipping stress and yet occupy merely 1.25% of protected ocean area. Additionally, 25.1% of collision hotspots (top 1% risk) affect four or more whale species, forming critical aggregation in regions like the Gulf of St. Lawrence and Northeast Asian marginal seas. Most of these high-risk areas lack protective measures. These findings offer actionable spatial priorities for implementing targeted conservation strategies, such as the introduction of mandatory speed restrictions and dynamic vessel routing in high-risk, multi-species hotspots. By focusing on critical aggregation areas, these strategies will help mitigate whale mortality and enhance marine biodiversity protection, supporting the sustainable coexistence of maritime activities with vulnerable marine megafauna. Full article

The future of marine sustainability depends on public understanding and trust in the policy recommendations that emerge from scientific research. For common pool marine resource decisions made by the people who depend on these resources for their food, employment, and economic future, understanding the current status of these marine systems and change is essential to ensure these resources will persist into the future. As such, the informal learning infrastructure is essential to increasing marine science literacy in a changing world. This mixed-methods research study analyzed the distribution and accessibility of marine science education and research across Alaska’s five geographic regions. Using the PRISMA framework, we synthesized data from 198 institutions and analyzed peer-reviewed literature on marine ecosystems to identify geographic and thematic gaps in access to informal science learning and research focus. In parallel, we undertook geospatial analysis and resource availability to describe the distribution of resources, types of informal learning infrastructure present across the state, regional presence, and resources to support informal marine science learning opportunities. Findings from this multifactor research revealed a concentration of resources in urban hubs and a lack of consistent access to learning resources for rural and Indigenous communities. The configurative literature review of 9549 publications identified topical underrepresentation of the Bering Sea and Aleutian Islands, as well as a lack of research on seabirds across all regions. Considered together, these results recommend targeted investments in rural engagement with marine science programming, culturally grounded partnerships, and research diversification. This review concludes that disparities in learning resource support and government-funded priorities in marine wildlife research have created conditions that undermine the local people’s participation in the sustainability of sensitive resources and are likely exacerbating declines driven by rapid change in Arctic and sub-Arctic waters. Full article

The global 30 × 30 initiative, endorsed by 188 countries, aims to expand terrestrial and marine protected areas to cover 30% of the planet by 2030. This study utilizes newly available species-occurrence maps from the Global Biodiversity Information Facility (GBIF) to identify conservation priorities in 10 countries across Latin America (Brazil, Costa Rica, and Ecuador), Africa (Cameroon, South Africa, and Madagascar), and the Asia–Pacific region (Papua New Guinea, Philippines, India, and China). By incorporating diverse taxa—including vertebrates, invertebrates, and plants—the analysis ensures equitable species representation in conservation planning. A spatial prioritization algorithm is employed to pinpoint areas where new protected regions can address biodiversity gaps, with a particular focus on endemic and unprotected species. The results highlight significant variation in initial conservation conditions, including existing protection levels and spatial distribution of unprotected species. Countries with high spatial clustering of unprotected species achieve substantial protection gains with modest protected-area expansions, while others may require exceeding the 30% target to ensure comprehensive biodiversity coverage. The study underscores the importance of localized conservation strategies within the broader global framework, demonstrating how targeted spatial planning can enhance biodiversity outcomes and support the equitable implementation of the 30 × 30 commitment. Full article

In Cuba, coastal zone management is a matter of environmental priority. The Cuban State has legislated its protection mechanisms, actions, and instruments according to a high-hierarchical-rank legal norm. This article revealed the institutional frameworks and implementation strategies that support the socio-ecosystemic approach in coastal marine governance in the southeastern region of Santiago de Cuba, focusing on the management practices of integrated coastal zone management (ICZM) programs. Under the logic of ICZM principles, a scientometric, exegetical–legal study was carried out, with thematic content analysis, using the Driving Forces–Pressures–State–Impacts–Respond (DPSIR) framework. The methodology to meet the objectives was based on three analytical stages that generated scientific proposals for implementing the socio-ecosystemic approach in adaptive coastal governance practices. As a result, it is demonstrated that this approach has a scientific and legal proposal in Cuba, and its dynamics in coastal management programs are revealed. This study indicates that the logic of the DPSIR framework provides a propositional platform that helps structure the fundamentals of the proposed approach with reference to objectives and responses of coastal marine governance in Cuba. Full article

Coralligenous bioconstructions are priority habitats crucial for the protection of Mediterranean marine biodiversity. Among these bioconstructions, the mesophotic biogenic reefs of the northern Adriatic are of particular concern due to their ecological relevance and the high levels of human pressure in the region. Thus, effective monitoring strategies are vital for the conservation and management of these fragile environments. In this study, we investigated the multivariate spatial and temporal patterns of sessile macrobenthos on biogenic reefs within two areas of a Natura 2000 site in the northern Adriatic over a four-year period. We also classified the ecological status of reefs based on the NAMBER index, specifically tailored for these peculiar bioconstructions. Our findings revealed that temporal trajectories of assemblages significantly differed between the two investigated areas, mostly due to larger fluctuations in algal turf abundance in the area closest to the coast, which is putatively more exposed to human impacts. In this area, the index identified a “Moderate” status during the period of peaking turf abundance, while the reef status consistently remained “Good” in other periods and in the area located further from the coast. This highlights the index sensitivity in reflecting actual changes in assemblages potentially associated with reef degradation. Full article

Anthropogenic threats from human activity have significantly altered global ecosystems, resulting in habitat destruction and fragmentation, biodiversity loss, and species extinction. The identification and establishment of protected areas for the conservation of threatened species is thus required to mitigate the impacts of these threats. This study identified priority conservation areas (PCAs) for endangered mammals, birds, amphibians, and reptiles in South Korea using ecological modeling. In particular, we used the MaxEnt model to determine the potential distributions of endangered species and Zonation software to prioritize conservation areas. In doing so, we aimed to identify key environmental factors that influence the distributions of the target species and to identify ecologically critical areas using gap analysis based on the first-grade areas on the ecology and nature map (ENM). The results indicated that the highest priority areas for endangered species varied by taxon, with endangered mammals found primarily in forested areas, endangered birds on inland plains, and endangered amphibians and reptiles within marine and stream regions. The gap analysis revealed a very low overlap between ecological areas and high-priority areas for endangered birds and amphibians. This suggests that the first-grade areas on the ENM mainly represent areas with high vegetational coverage. These findings highlight the need to reassess existing protected areas and designate PCAs for endangered species independently from the ENM. This study represents a foundational assessment that can be used to inform conservation planning and prompt continued ecological research in support of biodiversity conservation efforts. Full article

The Guangdong-Hong Kong-Macao Greater Bay Area (GBA) is one of the most urbanized and industrialized coastal regions in China, where intense human activities contribute to substantial terrestrial sediment discharge into the adjacent marine environment. However, complex hydrodynamic conditions and high spatiotemporal variability pose challenges for accurate suspended sediment concentration (SSC) retrieval. Developing water quality retrieval models based on different classifications of water bodies could enhance the accuracy of SSC inversion in coastal waters. Therefore, this study classified the coastal waters of the GBA into clear and turbid zones based on Hue angle α, and established retrieval models for SSC using a single-scattering approximation model for clear zones and a secondary-scattering approximation model for turbid zones based on radiative transfer processes. Model validation with in-situ data shows a coefficient of determination (R²) of 0.73, a root mean square error (RMSE) of 8.30, and a mean absolute percentage error (MAPE) of 42.00%. Spatial analysis further reveals higher SSC in the waters around Qi’ao Island in the Pearl River Estuary (PRE) and along the coastline of Guanghai Bay, identifying these two areas as priorities for attention. This study aims to offer valuable insights for SSC management in the coastal waters of the GBA. Full article

Acquiring high-quality images from space at low-latitude areas is challenging due to the orbital requirements of the satellites and the frequent cloud coverage. To address this issue, a low-latitude remote sensing satellite constellation—the Hainan Satellite Constellation (HSC)—was conceived with a spatial coverage-priority concept. This constellation integrates sensors with multispectral, hyperspectral, radar, and Automatic Identification System (AIS) capabilities for marine vessels with an onboard image processing technology. The design is tailored to the tropical/subtropical region. Once HSC becomes fully operational, it will provide high-frequency coverage in low-latitude regions, with a primary focus on ocean observations. The first four optical satellites (HN-1 01/02 and WC-1 01/02) were successfully launched in February 2022. They boast unique application characteristics, including satellite networking for ocean observations over large areas, onboard image processing and modeling for ship detection, as well as the synergy of onboard sensors with optical and ship AIS capabilities. This study focuses on the technical design and proposes implementation strategies for HSC, encompassing its technical characteristics, composition, and capacity. Additionally, it explores the construction of this satellite constellation and its uses while providing insights into potential follow-up satellites. Full article

Throughout the Caribbean region, coastal areas are of vital importance for national incomes from the tourism industry. However, accelerated coastal development has impacted the coastal ecosystems, including the beaches, and deterioration of the shore results from cumulative impacts on both marine and coastal ecosystems. It is essential to identify the areas that need special attention for targeted management plans and actions, especially in areas with high anthropogenic pressure. This research proposes an integrated assessment of the conservation state of shore and coastal ecosystems in the Puerto Morelos National Reef Park (PNAPM) in the Mexican Caribbean, through the spatial monitoring of key parameters. A Geographic Information System (GIS) was employed to analyze the land use on the shore, foredune condition, morphological characteristics of the beaches, shoreline evolution, and the condition of coral reefs and seagrass meadows. The analysis identified the most critical areas in relation to shore deterioration and priority areas for the preservation of ecosystems. The spatial data obtained for the PNAPM can serve as a basis for ongoing shore monitoring, and targeted management actions through the designation of areas that require either preservation or ecosystem restoration practices. This methodology can be applied to other reef systems in the Caribbean. Full article

Baleen whales are ecosystem sentinels of microplastic pollution. Research indicates that they likely ingest millions of anthropogenic microparticles per day when feeding. Their immense prey consumption and filter-feeding behavior put them at risk. However, the role of baleen, the oral filtering structure of mysticete whales, in this process has not been adequately addressed. Using actual baleen tissue from four whale species (fin, humpback, minke, and North Atlantic right) in flow tank experiments, we tested the capture rate of plastics of varying size, shape, and polymer type, as well as chemical residues leached by degraded plastics, all of which accumulated in the baleen filter. Expanded polystyrene foam was the most readily captured type of plastic, followed by fragments, fibers, nurdles, and spherical microbeads. Nurdle and microbead pellets were captured most readily by right whale baleen, and fragments were captured by humpback baleen. Although not all differences between polymer types were statistically significant, buoyant polymers were most often trapped by baleen. Plastics were captured by baleen sections from all regions of a full baleen rack, but were more readily captured by baleen from dorsal and posterior regions. Baleen–plastic interactions underlie various risks to whales, including filter clogging and damage, which may impede feeding. We posit that plastics pose a higher risk to some whale species due to a combination of factors, including filter porosity, diet, habitat and geographic distribution, and foraging ecology and behavior. Certain whale species in specific marine regions are of the greatest concern due to plastic abundance. It is not feasible to remove all plastic from the sea; most of what is there will continue to break into ever-smaller pieces. We suggest that higher priorities be accorded to lessening humans’ dependence on plastics, restricting entry points of plastics into the ocean, and developing biodegradable alternatives. Full article

As an important mode of transportation for the global trade, waterborne transportation has become a priority option for import and export trade due to its large load capacity and relatively low cost. Meanwhile, shipping safety has been highly valued. By collecting technological water traffic accident data from the EM-DAT database, the spatiotemporal distribution and evolution characteristics were investigated in Asia since 2000. The methods of gravity center and standard deviation ellipse analysis were utilized to determine the spatial and data-related characteristics of water traffic accidents. Temporally, the results indicated that accidents occurred most frequently during the seasons of autumn and winter, leading to a significant number of casualties. Spatially, both South-eastern Asia and Southern Asia emerged as regions with a high frequency of water traffic accidents, particularly along the borders of Singapore, Malaysia, Indonesia, and the Bay of Bengal region. In addition, the Daniel trend test and R/S analysis were conducted to demonstrate the evolution trend of accidents across various regions and seasons. The present study provides guidance for improving marine shipping safety, emergency resource management, and relevant policy formulation. Full article

The intensity of climate change impacts on coastal ecosystems is determined by a combination of global, regional, and local drivers. However, many studies on the impact of climate change on ecosystems only consider trends associated with global changes. To assess the global, regional, and local trends, this research analyzes different climates in the coastal zone of the Mexican Caribbean. These drivers include sea level rise in synergy with tectonic activity, sea surface temperature, atmospheric pressure, precipitation, waves and winds. Marine climate variability from 1980 to 2020 was assessed from historical records by local/governmental agencies and the European Centre for Medium-Range Weather Forecasting. An up-to-date diagnosis of local changes of the coastal ecosystems was made, the magnitudes of change differ from the global means, which must be considered when identifying local climate change impacts. Coastal ecosystems, such as mangroves, coastal dunes, sandy beaches and seagrass meadows, showed no changes consistent with geophysical drivers associated with climate change. The exception was coral reefs, where increasing SST is related to coral bleaching. Regional and local anthropic drivers or disturbances other than those related to climate change, including eutrophication, massive influxes of the brown algae Sargasso and changes in land use, induced degradation of the coastal ecosystems. Communities often do not have the capacity to cope with global climate change, but the main impacts on coastal ecosystems in the coastal zone studied were induced by regional and local drivers/disturbances that can be better managed using monitoring programmes and specific management strategies. Climate change induces pressures on coastal ecosystems that affect their functioning, physiology and species distribution; therefore, this study highlights the need to understand how climate-change-related phenomena will affect ecosystems and which geophysical drivers may have priority effects. It also highlights the importance of developing robust regional/local databases to enable stakeholders to diagnose the state of coastal ecosystems and to monitor the effectiveness of actions to prevent or reverse undesirable changes. Full article

Elasmobranchs are declining worldwide due to overfishing. In developing countries and island states in tropical regions, small-scale and recreational fisheries can significantly impact the dynamics of neritic species. We investigated elasmobranch diversity at Reunion Island, a marine biodiversity hotspot in the Western Indian Ocean. Combining information from the literature, catches from the local shark control program, results from a survey of local recreational fishing, and through barcoding of some specimens, we updated the list of elasmobranchs to 65 species. However, uncertainties remain about the actual presence of some species, such as the three sawfish species. Results highlight the disappearance of most coral reef-associated species, as already suspected. Results also suggest that local populations of scalloped hammerhead shark (Sphyrna lewini) and bottlenose wedgefish (Rhynchobatus australiae) seem healthy, in contrast with their decline in the region. For some species, such as bull sharks (Carcharhinus leucas) and scalloped hammerhead sharks, Reunion Island is a site of reproduction, and as such, the species are exploited at both juvenile and adult stages, which likely increases their vulnerability. In the context of global elasmobranch decline, it is urgent to clarify the conservation status and evaluate the degree of isolation of local populations to identify research and conservation priorities. Full article

Offshore wind farms (OWFs) can influence marine stratifications, leading to fuel nutrition in the upper ocean and regulating ocean carbon fluxes. Evaluating this dynamic effect facilitates the planning of OWFs deployment for enlarging marine carbon sequestration, which is urgent in the pursuit of China’s carbon neutrality targets. However, it is impossible to observe the target influence in the planning stage of deployments, and it is impractical to build a high-resolution (10⁰~10¹ m) model to cover the entire waters adjacent to China. The theoretical calculations, therefore, are the first step and top priority. The simplified theory presents two suggestions in the design of future OWF deployments in the study area. The first suggestion is made from the perspective of OWF positioning. To the east of the cities of Zhoushan, Putian, and Shantou, the oceans are dynamically sensitive to OWF deployments. The second suggestion is made from the perspective of the length scale of OWFs. A broader OWF results in a smaller vertical disturbance in the coastal waters, but the situation is opposite in the open seas. The OWF deployment strategy, proposed in the aim of ensuring idealized marine stratification responses, thus varies geographically. This study provides a panoramic view of the sensitivity of marine stratification to OWFs in the study regions. It can be seen as a steppingstone in detailed research of the target phenomenon. Full article