Search Results (152)

Tidal seashell waste represents an abundant, underutilized marine resource that poses environmental disposal challenges but offers potential as a sustainable bio-filler in epoxy composites. This study investigates its incorporation into bio-based epoxy systems to reduce reliance on non-renewable materials and promote circular economy objectives. Processed seashell powder was blended into epoxy formulations, and response surface methodology was applied to optimize filler loading and resin composition. Comprehensive characterization included tensile strength, impact resistance, hardness, density, and thermal conductivity testing, along with microscopy analysis to evaluate filler dispersion and interfacial bonding. The optimized composites demonstrated improved hardness, density, and thermal stability while maintaining acceptable tensile and impact strength. Microscopy confirmed uniform filler distribution at optimal loadings but revealed agglomeration and void formation at higher contents, which can reduce interfacial bonding efficiency. These findings highlight the feasibility of valorizing marine waste as a reinforcing filler in sustainable composite production, supporting environmental goals and offering a scalable approach for the development of durable, lightweight materials suitable for structural, coating, and industrial applications. Full article

The depletion of global fish stocks poses a major challenge to sustainable development, particularly in economies where marine resources are critical to livelihoods and food security. In this study, the relationship between economic development and the sustainability of fish stocks is examined using the Environmental Kuznets Curve (EKC). We use panel data from 32 economies between 2002 and 2020 and analyze the fish stock status indicator (EPI_FSS) from the Environmental Performance Index, which captures the proportion of national catches from overfished or collapsed stocks. Using a dynamic panel approach and the generalized method of moments (GMM), we investigate how the human development index (HDI) and other socio-economic factors influence changes in the state of fish stocks. Our results show a statistically significant inverted-U-shaped (∩-shaped) relationship between the HDI and the state of fish stocks, suggesting that the deterioration of fish stocks increases at lower levels of development, but improves beyond a certain threshold. In addition, higher levels of foreign direct investment (FDI), education, and research and development (R&D) spending are associated with better outcomes for fish stocks. These results suggest that while early economic growth may put pressure on marine resources, sustained investment in human capital, innovation, and global integration is critical to promoting long-term marine sustainability. Full article

Deep-sea mining presents a critical sustainability paradox; it offers access to essential minerals for the technologies of the green transition (e.g., batteries, wind turbines, electric vehicles) yet threatens fragile marine ecosystems. As the terrestrial sources of these materials face mounting geopolitical, environmental, and ethical constraints, undersea deposits are increasingly being viewed as alternatives. However, the extraction technologies remain unproven at large scales, posing risks related to biodiversity loss, sediment disruption, and altered oceanic carbon cycles. This paper explores how deep-sea mining might be reconciled with sustainable development, arguing that its viability hinges on addressing five interdependent challenges—technological readiness, environmental protection, economic feasibility, robust governance, and social acceptability. Progress requires parallel advancements across all domains. This paper reviews the current knowledge of deep-sea resources and extraction methods, analyzes the ecological and sociopolitical risks, and proposes systemic solutions, including the implementation of stringent regulatory frameworks, technological innovation, responsible terrestrial sourcing, and circular economy strategies. A precautionary and integrated approach is emphasized to ensure that the securing of critical minerals does not compromise marine ecosystem health or long-term sustainability objectives. Full article

This study provides empirical evidence on how the Marine Ecological Civilization Demonstration Zone program, a policy integrating industrial upgrading with ecological protection, achieves dual objectives in a developing economy context. Theoretically, we uncover three key mechanisms, including green technology innovation, productivity gains, and government intervention, that explain the program’s impacts, offering a framework for reconciling industrialization with environmental sustainability. Our novel findings demonstrate that the program significantly boosts industrial structure upgrading and coastal water quality, with pronounced effects in the Pearl River Delta. We highlight the need for regionally tailored measures, expanded green R&D support, and strategic zone expansion insights critical for China and other developing nations navigating similar trade-offs. By bridging the gap between environmental regulation and industrial transformation, this work contributes to the debates on sustainable development in coastal regions. Full article

This paper aims to provide a reliable basis for formulating, revising, and selecting sustainable marine economic development plans through a scientific and comprehensive evaluation of the eco-innovation level of China’s marine economy. Based on the analysis of the three-stage theoretical model of marine economic eco-innovation, an index system for evaluating the eco-innovation level of China’s marine economy is first constructed. Also, an integration EWM-HDEMATEL method that balances objective and subjective weighting is introduced to determine the index weights. The proposed methods are applied to analyze the temporal and spatial variations in the eco-innovation level of China’s marine economy in 2006–2021, and the following conclusions are drawn. First, between 2006 and 2021, the average level of marine economic ecological innovation across all regions exhibited a steady upward trajectory. Second, regional imbalances in ecological innovation intensified over the study period, with the maximum disparity widening from a 1.6-fold difference in 2006 to a 2.5-fold difference in 2021. Third, although differences among the three principal marine economic zones were not pronounced, significant heterogeneity persisted within each zone, underscoring the need for targeted policies and interventions to achieve coordinated development. Fourth, regions performed better on the support environment and performance dimensions of marine economic ecological innovation than on the capacity and activity dimensions. These findings identify critical leverage points for policy action and carry important implications for promoting the balanced and sustainable development of marine economic ecological innovation efficiency. Full article

Lightweight concrete (LWC) has emerged as a transformative material in sustainable and high-performance construction, driven by innovations in engineered lightweight aggregates, supplementary cementitious materials (SCMs), fiber reinforcements, and geopolymer binders. These advancements have enabled LWC to achieve compressive strengths surpassing 100 MPa while reducing density by up to 30% compared to conventional concrete. Fiber incorporation enhances flexural strength and fracture toughness by 20–40%, concurrently mitigating brittleness and improving ductility. The synergistic interaction between SCMs and lightweight aggregates optimizes matrix densification and interfacial transition zones, curtailing shrinkage and bolstering durability against chemical and environmental aggressors. Integration of recycled and bio-based aggregates substantially diminishes the embodied carbon footprint by approximately 40%—aligning LWC with circular economy principles. Nanomaterials such as nano-silica and carbon nanotubes augment early-age strength development by 25% and refine microstructural integrity. Thermal performance is markedly enhanced through advanced lightweight fillers, including expanded polystyrene and aerogels, achieving up to a 50% reduction in thermal conductivity, thereby facilitating energy-efficient building envelopes. Although challenges persist in cost and workability, the convergence of hybrid fiber systems, optimized mix designs, and sophisticated multi-scale modeling is expanding the applicability of LWC across demanding structural, marine, and prefabricated contexts. In essence, LWC’s holistic development embodies a paradigm shift toward resilient, low-carbon infrastructure, cementing its role as a pivotal material in the evolution of next-generation sustainable construction. Full article

Hydrogen compression is a critical process in hydrogen storage and distribution, particularly for energy infrastructure and transportation. As hydrogen technologies expand beyond limited industrial applications, they are increasingly supporting the green economy, including offshore energy systems, smart ports, and sustainable marine industries. Efficient compression technologies are essential for ensuring reliable hydrogen storage and distribution across these sectors. This study focuses on optimizing hydrogen compression using a Liquid Piston Hydrogen Compressor through numerical simulations and scaling analysis. The research examines the influence of compression chamber geometry, including variations in radius and height, on thermal behavior and energy efficiency. A computational model was developed using COMSOL Multiphysics^® 6.0, incorporating Computational Fluid Dynamics (CFD) and heat transfer modules to analyze thermodynamic processes. The results highlight temperature distribution in hydrogen, working fluid, and chamber walls at different initial pressures (3.0 MPa and 20.0 MPa) and compression stroke durations. Larger chamber volumes lead to higher temperature increases but reach thermal stabilization. Increasing the chamber volume allows for a significant increase in the performance of the hydraulic compression system with a moderate increase in the temperature of hydrogen. These findings provide insights into optimizing hydrogen compression for enhanced production and broader applications. Full article

The meat industry is one of the main sources of organic waste in the food processing sector. Due to their high content of biodegradable organic matter, these wastes represent a potentially valuable resource for the development of recycling and valorization processes, particularly with regard to the circular economy and environmental sustainability. The present study aimed at assessing the potential of natural sheep casings waste (NSCW) as a source of nitrogen for promoting the growth and lipid production of Scenedesmus rubescens MDP19, a marine microalga isolated from the Mediterranean coastline of northern Morocco. For this purpose, we evaluated the effects of different NSCW concentrations (0.25–5 g L⁻¹) on the microalga growth, its ability to utilize organic waste components (proteins, amino acids, and carbohydrates) as nutrients, and its efficiency in eliminating nitrogen and phosphorus. Lipid and pigment contents were determined using colorimetric methods, and their composition was analyzed by high-performance liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS/MS). The results showed that S. rubescens MDP19 achieved the highest biomass production of 1.737 g L⁻¹ at an NSCW concentration of 5 g L⁻¹. This strain removed 33.70–47.63% of protein, 71.84–87.62% of amino acids, 41.9–92.97% of carbohydrates, 59.72–99.30% of nitrogen, and 80.74–99.10% of phosphorus. Furthermore, S. rubescens MDP19 showed a significantly enhanced lipid content (68.11%) at an NSCW concentration of 0.5 g L⁻¹. At this concentration, the lipid composition of S. rubescens MDP19 was particularly complex, including monounsaturated and polyunsaturated fatty acids, digalactosyldiacylglycerols, sulfoquinovosyldiacylglycerols, phosphatidylglycerols, and acylglycerols. The pigment profile includes neoxanthin, canthaxanthin, lutein, chlorophyll a, geranylgeranyl chlorophyll a, chlorophyllide b, hydrochlorophyllide b, and pheophytin a. These results indicate that natural sheep casings waste represents a promising source of nitrogen, reducing the need for nutrient supplementation in microalgae production. This approach not only offers a sustainable and economical alternative for optimizing microalgae cultivation but also contributes to the valorization of organic waste, thus supporting more ecological and responsible practices. Full article

Biological invasions are one of the main causes of biodiversity loss globally, affecting the quality of ecosystem services, the economy, and public health. Research on the presence, distribution, impacts, and introduction pathways of invasive alien species is essential for understanding and tackling the invasion process. Continental, coastal, and marine aquatic ecosystems of the Yucatan Peninsula concentrate a high number of native species; however, the states that are in the region (Campeche, Yucatan, and Quintana Roo) also have the largest loss of natural capital at the national level. The presence of aquatic invasive species has contributed to this downward trend, mainly in protected areas. For this research, an analysis of the national biodiversity information system, the global biodiversity information facility, and the specialized scientific literature was carried out to determine the presence of aquatic invasive species within the protected areas of the Yucatan Peninsula and adjacent marine zone. The results indicated that there are 22 documented aquatic invasive species in 25 protected areas, which were classified into the following taxonomic groups: marine macroalgae (3 species), plants (2), inland and marine fish (11), crustaceans (2), mollusks (2), and hydrozoans (2). A total of 15 of these species had a very high invasiveness score, 6 had a high score, and 1 had a medium score. This research will be useful in strengthening regional public policy and guiding decision makers on the management of aquatic invasive species, mainly for those that are seriously affecting aquatic ecosystems, such as Pterygoplichthys disjunctivus and P. pardalis in freshwater protected areas and Pterois volitans in marine protected areas. Efficient management strategies will be a key element in the protection of biodiversity and ecosystem services, and for sustainable regional development. Full article

This review addresses the growing demand for sustainable alternatives to conventional synthetic nets used in marine and agricultural applications, which are often persistent, poorly degradable, and difficult to manage at end of life. It examines recent developments in biodegradable polymers—particularly polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and poly(butylene adipate-co-terephthalate) (PBAT)—alongside reinforced blends and nanocomposites designed to improve mechanical performance and degradation behavior under real-world conditions. Strategies based on the regeneration of discarded nets, especially those made from polyamide 6 (PA6), are also considered for their potential to close material loops and reduce environmental leakage. A critical analysis of current testing protocols and regulatory frameworks is provided to assess their suitability for novel materials. In addition, this study highlights the emergence of multifunctional nets capable of providing environmental sensing or biological support, marking a transition toward adaptive and ecosystem-responsive designs. Finally, a survey of ongoing European and international projects illustrates scalable pathways for implementing biodegradable and recyclable netting systems, integrating material innovation with circular economy strategies. These findings emphasize the need for harmonized standards, targeted environmental testing, and cross-sectoral collaboration to enable the large-scale adoption of sustainable net technologies. Full article

This literature review critically examines the development and optimization of sustainable energy and exergy analysis software specifically designed for offshore wind farms, emphasizing the transformative role of machine learning (ML) in overcoming operational challenges. Offshore wind energy represents a cornerstone in the global transition to low-carbon economies due to its scalability and superior energy yields; however, its complex operational environment, characterized by harsh marine conditions and logistical constraints, necessitates innovative analytical tools. Traditional deterministic methods often fail to capture the dynamic interactions within wind farms, thereby underscoring the need for ML-integrated approaches that enhance precision in energy forecasting, fault detection, and exergy analysis. This PRISMA-ScR review synthesizes recent advancements in ML techniques, including Random Forest, Long Short-Term Memory networks, and hybrid models, demonstrating significant improvements in predictive accuracy and operational efficiency. In addition, it critically identifies current gaps in existing software tools, such as inadequate real-time data processing and limited user interface design, which hinder the practical implementation of ML solutions. By integrating theoretical insights with empirical evidence, this study proposes a unified framework that leverages ML algorithms to optimize turbine performance, reduce maintenance costs, and minimize environmental impacts. Emerging trends, such as incorporating digital twins and Internet of Things (IoT) technologies, further enhance the potential for real-time system monitoring and adaptive control. Overall, this review provides a comprehensive roadmap for the next generation of software tools to revolutionize offshore wind farm management, thereby aligning technological innovation with global renewable energy targets and sustainable development goals. Full article

The growing scarcity of freshwater has accelerated the global deployment of desalination technologies, especially reverse osmosis (RO), as an alternative to meet increasing water demands. However, this process generates substantial quantities of brine—a hypersaline waste stream that can severely impact marine ecosystems if improperly managed. This perspective review explores the use of urease-driven Microbially Induced Carbonate Precipitation (MICP) as a biotechnological solution aligned with circular economy principles for the treatment and valorization of RO brines. Through the enzymatic activity of ureolytic microorganisms, MICP promotes the precipitation of calcium carbonate and other mineral phases, enabling the recovery of valuable elements and reducing environmental burdens. Beyond mineral capture, MICP shows promise in the stabilization of toxic metals and potential integration with microbial electrochemical systems for energy applications. This review summarizes current developments, identifies existing challenges, such as microbial performance in saline conditions and reliance on conventional urea sources, and proposes future directions focused on strain optimization, nutrient recycling, and process scalability for sustainable implementation. Full article

The long-term sustainability of seaports depends on various operational factors, including infrastructure efficiency, digital innovation, environmental management, and regulatory compliance, among which maritime pilotage plays a crucial role in ensuring safe navigation and minimizing environmental, economic, and social risks. This research employed the PRISMA-ScR framework to evaluate the environmental, economic, and social impacts of pilotage on the sustainability of seaports. The findings demonstrate efficient navigation and spill avoidance, which reduce emissions, safeguard marine biodiversity, and maintain water quality. Economically, it reduces delays, optimizes operational expenses, and increases port competitiveness by increasing maritime traffic. Moreover, pilotage improves navigational safety, local professional skill development, and community interactions via ecological conservation and operational efficiency. It also indicates how environmental initiatives benefit the economy, increase port competitiveness, and promote job security and community happiness. The results also emphasize the significance of pilotage in sustainable seaport operations by quantifying pollution reductions, cost savings, and safety. The result also suggests that successful pilotage enhances ports’ viability and responsibility in global shipping networks while addressing environmental, economic, and social concerns. Full article

The international seabed area (“the Area”) harbors abundant metal mineral resources that are critical to address global metal supply–demand and sustainable development. However, exploitation of mineral resources in the Area faces complex risks spanning politics, economy, technology, science, environment, society, industry, and law. No commercial-scale deep-sea mining operations have been conducted to date. Systematic risk identification and prioritization can inform strategic planning for stakeholders. This study employs literature analysis and an 80-expert questionnaire to identify key risk factors affecting mineral exploitation in the Area. Using the Analytic Hierarchy Process (AHP), we quantitatively assess the relative importance and weightings of these risks. Our results indicate that Level 1 risk groups prioritize (1) policy and public opinion risk, (2) extended continental shelf (ECS) delineation risk, (3) high sea marine protected areas (HSMPAs) establishment risk, and (4) mining area economic value risk. The five most critical Level 2 risk factors are (i) policy changes in contractor states, (ii) ECS-mining area boundary conflicts, (iii) environmental provisions in exploitation regulations at the international seabed (ER), (iv) ER implementation delays, and (v) mineral resource uncertainty. These findings provide actionable insights for contractors, policymakers, and stakeholders to optimize decision making in deep-sea mining projects. Full article

Against the backdrop of global warming, the marine low-carbon economy has emerged as a crucial pathway to achieving carbon peaking and carbon neutrality goals. This paper develops an evaluation index system for the marine low-carbon economy and carbon emission reduction. Using data from China’s coastal provinces (2012–2021), the study employs methods such as the entropy weight method, the coupled coordination model, K-means++ clustering, and grey correlation analysis to analyze the interaction between the marine low-carbon economy and carbon emission reduction. The study revealed the following findings: (1) From 2012 to 2022, the development of the marine low-carbon economy exhibited an “N”-shaped pattern, while the trend of carbon emission reduction generally followed the opposite pattern due to a “lag” effect. (2) The coordination between the two systems improved gradually, reaching an intermediate level from 2018 to 2021. (3) Among the internal factors related to the interaction between the marine low-carbon economy and carbon emission reduction, fossil energy consumption and wetland areas are the primary sensitivity factors. (4) External factor analysis through the use of grey correlation analysis revealed that the structure of the marine industry and technological innovation are the main drivers of the interaction, while carbon market trading showed the lowest correlation out of all the external factors, indicating that the mechanism design needs further improvement. (5) Compared with other coastal countries, China still has much room for progress in regard to the construction of MPAs and the restoration of blue carbon ecosystems. This paper introduces a method to quantify the development level of the marine low-carbon economy and assess the effects of marine carbon emission reduction, analyzing the coupling coordination between China’s marine low-carbon economy and carbon emission reduction. This research provides a foundation for Chinese policymakers and offers insights into green and sustainable development of the global marine economy. Full article