Ocean warming is rapidly altering marine ecosystems and is negatively affecting marine invertebrates, especially during their earlier life stages which often exhibit narrower physiological tolerances than adult conspecifics. The Caribbean king crab (Maguimithrax spinosissimus) is a species of interest for coral reef restoration in the Florida Keys and throughout the Caribbean due to its herbivorous grazing which can reduce macroalgae cover on patch reefs. However, the effects of thermal stress on king crab larval physiology and swimming behavior remain unknown. This study determined the effects of thermal stress on survival, metabolic performance, and geotactic vertical swimming behavior in both of the larval stages of M. spinosissimus under two temperature treatments: 28 °C (control) and 32 °C (elevated). Exposure to elevated temperature significantly reduced larval survival, with larvae in 32 °C being nearly three times more likely to die than cohorts in the control. In contrast, oxygen consumption did not differ between temperature treatments or larval stages, however larvae in the elevated treatment were observed to be more lethargic (alive with tail movement but no longer swimming) than larvae in the control. Elevated temperature also resulted in a reversal in the geotactic vertical swimming response. First stage larvae significantly swam downward at a faster rate than individuals in the control. In the absence of acclimatization, these results suggest that outplanted king crab populations may experience a reduction in larval supply and a reduced dispersal potential which could limit connectivity among local reef habitats after outplanting. This research has implications for coral reef restoration programs interested in stocking king crabs onto reefs as those efforts will rely on successful recruitment to sustain outplanted populations of M. spinosissimus.
Autonomous underwater gliders are pivotal for sustained ocean observations; however, maximizing effective data utilization requires highly standardized, end-to-end data processing workflows. Despite the availability of generic glider toolboxes, to our knowledge, no published open-source workflow currently provides an end-to-end, SeaExplorer-specific processing chain from vendor raw files to CF-compliant, quality-controlled outputs. Here, we present a Python-based pipeline that standardizes post-mission raw SeaExplorer data, applies automated Quality Control (QC) tests, and generates both diagnostic and user-oriented products designed for reproducible scientific use. This framework is designed to automate, under expert supervision, the entire processing chain, from raw data ingestion to the generation of CF-compliant NetCDF files. The proposed workflow implements a QC approach, adhering to the principle of data preservation over elimination, ensuring that original data are preserved for future scientific re-evaluation. The framework applies a suite of fourteen QC tests and produces two distinct outputs: a granular diagnostic file preserving detailed per-test flags for technical validation, and an aggregated file providing a single quality indicator per variable for immediate scientific use. The pipeline was demonstrated using data from two SeaExplorer missions conducted in La Palma (Canary Islands). Designed according to FAIR (Findable, Accessible, Interoperable, Reusable) principles, this tool supports reproducible data management and facilitates the integration of operational engineering data into scientific workflows.
Climate change induced warming of temperate coastal waters is expected to affect the biodiversity, community structure, seasonality and production in planktonic protist communities, and benefit heterotrophic taxa. We investigated long-term changes in the plankton protist community of the Outer Oslofjord by comparing two distinct periods across 15 years (2009–2011 vs. 2023–2024). Monthly 18S rRNA gene metabarcoding (V4 region) revealed dinoflagellates and diatoms as the dominating major taxonomic groups, with a 5.6-fold decrease in the dinoflagellate:diatom ratio and a 3.1-fold decrease in the heterotrophic dinoflagellate:phototrophic dinoflagellate ratio. These changes were primarily driven by a decrease in relative read abundance of the heterotrophic dinoflagellate genus Gyrodinium, and a widespread increase in the relative read abundances of diatoms (24 out of 27 ASVs with significant increase) between the time periods. Our results indicate that projected trends of heterotrophic protists profiting from changing oceanic conditions due to climate change, e.g. in temperate coastal waters, may not be the case for all coastal ecosystems.
Underwater ecosystems play a crucial role in maintaining marine biodiversity and global environmental sustainability. However, underwater monitoring and imaging is a highly challenging area of image processing, where images are severely degraded by haze, wavelength-dependent light absorption, color distortion, scattering, and noise, affecting marine monitoring, object detection, underwater navigation, and limited assessment of coral reefs, marine organisms, benthic habitats, and water quality. The conventional anisotropic diffusion filters do not effectively suppress noise and often fail to adequately preserve image edges and structural details. The manual selection of conductance parameters done in existing methods does not adequately account for the physical degradation mechanisms present in underwater environments. To address these limitations, a new framework, known as Rayleigh scattering-adapted diffusion anisotropic filter (RSADAF), has been proposed, which is a wavelength-aware physics-based diffusion framework that integrates a second-order partial differential equation (PDE) diffusion with the atmospheric scattering model (ASM) and Rayleigh scattering law. The adaptive conductance gradient parameter has been derived from ambient light estimation, and the dominant wavelength of the images has been derived from the CIE 1931 chromaticity model, giving spatial variation of diffusion and reducing local degradations. The second-order PDE formulation (two-stencil approach) preserves the structural information and mitigates staircase artifacts commonly observed in conventional diffusion schemes. Experimental evaluation on the EUVP and UIEB benchmark datasets demonstrates that the proposed approach achieves superior enhancement performance in terms of both full-reference and no-reference image quality metrics. The CIE 1931 wavelength-aware framework achieved a PSNR of 42.85 dB, SSIM of 0.967, UCIQE of 0.341, and BRISQUE of 21.99, outperforming conventional anisotropic diffusion and related enhancement methods. Visual results further confirm improved color restoration, contrast enhancement, edge preservation, and texture retention, offering an interpretable, computationally efficient, and physically meaningful alternative solution for underwater imaging applications.
The large yellow croaker (Larimichthys crocea) is an economically important marine fish in China. In order to explore the feasibility of inland saline-alkaline water aquaculture, this study systematically compared the effects on gonadal development of 14-month-old large yellow croaker, cultured in two different culture environments (offshore seawater in Ningde, and indoor saline-alkaline water in Ningxia). The evaluation was conducted on multiple parameters, including growth parameters, gonadosomatic index, sex ratio, gonadal histology, sex hormone levels (progesterone, estradiol, testosterone), and gonadal transcriptomes. The results showed no significant differences in growth and gonadal development between the two environments, with both ovaries at early developmental stages (phase I–III oocytes) and testes fully mature with abundant sperm. However, saline-alkaline water culture significantly reduced gonadal estradiol and testosterone levels in females, while increased progesterone levels in males. Transcriptomic analysis revealed a striking sex-specific response: females exhibited 8,744 differentially expressed genes (6,518 up-, 2,226 down-regulated), whereas males showed only two upregulated genes. GO and KEGG enrichment analyses of female differentially expressed genes indicated profound effects on energy metabolism, ovarian steroidogenesis, and cell cycle pathways. qRT-PCR validated the RNA-seq results. In conclusion, the saline-alkaline water environment in Ningxia does not impair gonadal development of large yellow croaker up to 14 months of age. Females undergo extensive transcriptomic reprogramming and hormonal changes, while males remain transcriptionally stable. These findings support the feasibility of the “marine fish inland farming” model, which alleviates pressure on coastal aquaculture, utilizes underappreciated saline-alkaline water resources, and promote coordinated regional development.
IntroductionModern armed conflicts at sea frequently trigger transboundary marine pollution, inflicting irreversible damage on regional ecological baselines; however, contemporary international law exhibits a pronounced normative deficit in regulating such harm.MethodsEmploying doctrinal legal analysis and systematic interpretation, this study deconstructs and maps core legal norms—including Article 35(3) of Protocol Additional I to the Geneva Conventions and Article 192 of the United Nations Convention on the Law of the Sea (UNCLOS)—alongside key judicial precedents to examine the normative interaction between International Humanitarian Law (IHL) and the law of the sea during wartime.ResultsThe findings reveal a structural misalignment between the permissive logic of military necessity and the protective logic anchored in obligations erga omnes. Under strict judicial interpretation, the threefold cumulative threshold of "widespread, long‑term and severe" presents an insurmountable evidentiary barrier, creating a critical accountability void in modern naval warfare characterised by grey‑zone operations and non‑state actors.DiscussionTo bridge these lacunae, this study formulates a collaborative governance framework grounded in Article 31(3)(c) of the Vienna Convention on the Law of Treaties (VCLT). At the macro level, it transposes the ecological vulnerability assessment criteria of Particularly Sensitive Sea Areas (PSSAs) into the IHL framework to reconstruct a legal mechanism for wartime special marine ecological protection zones, while drawing analogies from Articles 100 and 107 of UNCLOS to establish a cooperative universal visit‑and‑search mechanism targeting wartime environmental hazards. At the micro level, using the domestic legal integration of China's maritime rights enforcement as an illustrative case, it demonstrates a feasible pathway for sovereign states to fill international legal vacuums via domestic legislation. Ultimately, this research underscores that effective wartime marine environmental protection requires a paradigm shift in international law—transitioning from a pure "law of war regulation" toward a framework that actively safeguards common interests.
Marine biofouling poses a significant challenge for ocean engineering, with microbial biofilm formation being a critical prerequisite for macrofouling colonization. Traditional chemical antifouling strategies face increasing restrictions due to ecological toxicity and microbial resistance, creating an urgent demand for eco-friendly physical alternatives. This study aimed to systematically compare the wavelength-dependent effects of 405 nm and 450 nm antimicrobial blue light on Halomonas pacifica biofilm formation. Biofilms were constructed on glass slides and continuously irradiated at 50 mW/cm2 for 4 days (cumulative radiant exposure about 17,280 J/cm2), with a non-irradiated control. Total biomass was quantified by crystal violet staining, three-dimensional morphology was analyzed by white light interferometry, and bacterial viability was visualized by confocal laser scanning microscopy with DMAO/PI staining. The 450 nm treatment significantly reduced total biofilm biomass by 20.9% (P < 0.05), while 405 nm decreased biomass by 15.5% without statistical significance. In contrast, 405 nm strongly suppressed vertical growth, reducing average dry thickness by 77.2% (P < 0.01) and arithmetic mean roughness (Ra) by 55.0% (P < 0.01), whereas 450 nm optimized overall micromorphology by reducing maximum height (Sz, P < 0.05). Confocal imaging revealed dense continuous biofilms in controls, sparse fragmented structures in the 450 nm group, and intermediate density in the 405 nm group. These results indicate that the two wavelengths regulate biofilm formation through distinct mechanisms: 450 nm excels in inhibiting proliferation and reducing biomass, while 405 nm is superior in suppressing vertical thickening and minimizing attachment sites for subsequent macrofouling. This study demonstrates that 405 nm and 450 nm blue light are promising complementary strategies for eco-friendly marine antifouling.
Polychlorinated biphenyls (PCBs) are legacy pollutants associated with numerous adverse health effects. We synthesized PCB and health data collected over multiple decades and across six bottlenose dolphin (Tursiops spp.) populations, including a population near the heavily PCB-contaminated LCP Chemicals Site in Brunswick, Georgia, US. We used samples from males and juvenile females (n=396) to compare PCBs across populations, explore fine-scale spatial trends near the LCP Chemicals Site, and examine temporal trends for bottlenose dolphins sampled near Brunswick, and near Charleston, South Carolina. As females depurate a large portion of their PCB burden to their offspring, we also used the full sample set (n=580) to examine timing of decrease in blubber PCB burden in females as an indicator of first successful reproduction. Finally, we investigated associations of PCB concentrations with health indicators and thyroid hormones. We found that, although PCBs declined over time (3.54% and 5.01% decline per year for Brunswick and Charleston, respectively), concentrations are still extremely high in dolphins sampled near the LCP Chemicals Site. Geometric mean total PCBs combined over years for the Brunswick population was 236 (95% CI:198–280) μg/g lipid, but ranged from only 46 to 60 μg/g lipid for populations outside southern Georgia. At Brunswick, concentrations of summed congeners of Aroclor 1268, the commercial PCB mixture associated with LCP Chemicals Site operations but rarely used elsewhere, decreased with increasing sampling distance from the site. The median age for females classified to the sample group that had presumably successfully reproduced, indicated by decreased PCB concentration, was 20.4 years for Brunswick, compared with 11.6 years for other populations, suggesting that Brunswick females experience a number of failed attempts at breeding prior to their first success. Aroclor 1268 levels were associated with decreases in health indicators. Strongest associations were with alkaline phosphatase and albumin; for both, low measures have been associated with substantial increase in mortality risk for dolphins. In addition, all three thyroid hormones decreased with increasing Aroclor 1268. Previous human studies have found that hypothyroidism is associated with infertility, miscarriage, and poor fetal outcome, suggesting a likely pathway for PCB-related effects on reproduction in bottlenose dolphins.
IntroductionLongitudinal bending distortion is a major manufacturing problem in thin-walled T-beam stiffened structures used in large Pure Car and Truck Carrier (PCTC) ships. This study investigates the formation mechanism of welding distortion under different welding speeds and develops an induction-assisted dynamic thermal tensioning method for active distortion control.MethodsThermo-elasto-plastic finite element models were established to investigate the transient temperature field, plastic-zone evolution, residual stress distribution, and bending distortion of T-beams under high- and low-speed welding conditions. A temperature-dependent modified Johnson–Cook constitutive model for AH36 steel was developed from tensile tests at multiple temperatures and strain rates and implemented in ABAQUS through a UMAT subroutine. The constitutive model was validated against an independent AH36 butt-welding experiment. The effects of induction heating temperature and heating distance were then investigated numerically, followed by full-scale validation on a high-speed tandem submerged arc welding production line for large PCTC shipbuilding.ResultsLow-speed welding produced a larger plastic compression zone and greater longitudinal shrinkage strain accumulation because of the longer high-temperature residence time, resulting in more severe final longitudinal bending distortion. High-speed welding was mainly characterized by transient thermo-elastic sagging during the welding stage. Induction-assisted dynamic thermal tensioning effectively reduced longitudinal bending distortion by regulating the temperature field and longitudinal shrinkage in the web region. The best-performing induction heating conditions depended on the welding speed. In the full-scale production experiments, the selected induction heating parameters reduced the longitudinal bending distortion of the T-beam by up to 66.7%, and the observed regulation trends were consistent with the numerical results.
Rapid glacier retreat across the Arctic is transforming coastal landscapes and generating a growing number of previously non-existent aquatic habitats. In Svalbard, this process has led to the formation and expansion of coastal lagoons, including a substantial proportion of newly emerged paraglacial systems. Despite their increasing abundance, these environments remain poorly represented in Svalbard research and monitoring programs, and their ecological and biogeochemical significance is only beginning to be recognized. Herein we synthesize current knowledge of Svalbard coastal lagoons, integrating perspectives from geomorphology, hydrology, ecology, and biogeochemistry. We propose that these systems form a developmental continuum, ranging from newly formed, glacier-influenced basins to more stable and biologically structured lagoons. Observations from recently studied lagoon systems indicate strong environmental gradients, spatial heterogeneity and dynamic hydrological conditions that support diverse and evolving biological communities across trophic levels. Emerging evidence suggests that Arctic lagoons may function as biogeochemical reactors, including potential sources of methane, while also acting as accumulation zones for contaminants such as microplastics and persistent organic pollutants. At the same time, their ecological role – as biodiversity hotspots, transitional habitats, or stepping-stones for species redistribution – remains insufficiently understood. We identify key knowledge gaps related to lagoon formation, physical dynamics, ecosystem development, and greenhouse gas fluxes and outline a research roadmap for coordinated interdisciplinary investigations. We argue that Svalbard lagoons represent a rapidly expanding nature type that provides a unique opportunity to study ecosystem development under climate change and should be integrated into future Arctic research and assessment frameworks.
Robust and versatile detection of maritime vessels present in aerial images is a considerable challenge. While neural networks, particularly convolutional neural networks (CNNs), have revolutionized object detection and classification across many industries by enabling machines to learn complex patterns and features from large datasets, maritime vessel detection continues to pose challenges. One challenge is the limited quantity and diversity of training data required by AI/ML systems. In this paper, we present a system which uses multiple sensors in conjunction with salient data augmentation techniques and multiple convolutional neural network (CNN) architectures to test cross-sensor object detection resiliency. Our system is composed of six main subsystems: Image Acquisition, Image Processing, Data Augmentation, Model Creation, Object-of-Interest Detection and System Validation. We show that the data augmentation subsystem improves cross-sensor vessel detection precision by over 10%, paving the way for the design of similar systems which can prove robust across maritime applications, sensors and dataset sizes.
Reliable maritime object detection and tracking are essential for civilian ocean engineering applications, including vessel traffic monitoring, offshore infrastructure inspection, port management, marine debris surveillance, sea ice observation, hydrographic surveying, and environmental risk assessment. However, complex ocean environments present substantial challenges for automated perception systems because of dynamic sea surfaces, sea clutter, low SNRs, atmospheric interference, scale variation, occlusion, weak target signatures, and limited annotated datasets. This review examines recent advances in ocean-aware deep learning for maritime detection, segmentation, localization, and tracking using optical, infrared, Synthetic Aperture Radar (SAR), multibeam echosounder (MBES), satellite, airborne, unmanned aerial vehicle (UAV), unmanned surface vehicle (USV), and autonomous sensing data, together with Automatic Identification System (AIS) information. It synthesizes methodological developments in robust feature extraction, multi-scale representation, small-object detection, multimodal data fusion, weakly supervised learning, domain adaptation, and tracking under intermittent visibility. Existing limitations remain in sea-state annotation, cross-sensor benchmarking, long-term tracking datasets, operational validation, and real-time deployment. Future research should prioritize sea-state-aware architectures, physics-informed learning, SAR–optical–AIS–MBES–USV data fusion, synthetic data generation, lightweight implementation, and standardized evaluation protocols. These directions are critical for developing reliable civilian maritime monitoring systems under diverse sensor, weather, and ocean conditions.
IntroductionPrecise population monitoring of beluga whales (Delphinapterus leucas) is crucial for Arctic conservation management; yet, the manual annotation of aerial drone imagery is costly and logistically challenging. Calf detection is particularly important because calf presence and survival rates are indicators of reproductive health, recruitment success, and long-term population viability. However, calves are challenging detection targets due to their smaller size, lower frequency, and greater variability in appearance compared with adults. Although deep learning-based object detection offers considerable potential for automated wildlife monitoring, supervised approaches typically require large quantities of manually annotated data, limiting their application in conservation programs with restricted annotation resources.MethodsThis study systematically evaluated semi-supervised marine mammal detection from aerial imagery by comparing SEMI-DETR, a semi-supervised detection transformer, with four variants of YOLO11 across seven annotation budgets ranging from 1% to 50% of labeled data. Experiments were conducted using a bespoke dataset of 7,655 high-resolution aerial drone images annotated for adult and calf classifications.ResultsSEMI-DETR achieved a mean Average Precision (mAP) of 19.2 at 0.5:0.95 using only 34 labeled images (1% annotation budget), representing a 20% relative improvement over the best-performing supervised baseline. The performance advantage peaked at +6.6 mAP points at the 5% labeling level. Semi-supervised learning particularly improved calf detection, achieving a 24.3% relative improvement at 1% labeling compared with 16.8% for adults. Overall, comparable detection performance could be achieved with a 5- to 10-fold reduction in annotation requirements without substantially compromising detection quality.DiscussionThese findings demonstrate that semi-supervised learning can substantially reduce annotation requirements for automated marine mammal detection, with particularly strong benefits for the detection of calves. Improved calf detection has direct implications for population assessment and the monitoring of reproductive success and recruitment in beluga populations. This study establishes an empirical benchmark for semi-supervised marine mammal detection and provides practical guidance for allocating limited annotation resources in wildlife monitoring and conservation applications.
Climate change has posed significant global challenges, with multilateral mechanisms proving inefficient for small island states. These states thus requested an advisory opinion from the International Tribunal for the Law of the Sea (ITLOS) on climaterelated marine obligations, leading to written statements from state parties constructing their positions on the Tribunal’s advisory jurisdiction and climate issues. Drawing on SFL’s affiliation perspective and constructivist theories of state identity integrated with an ecological philosophy of law framework, this study conducts a comparative analysis of written statements submitted by China, Indonesia, and the EU. The findings reveal that China adopts a textualist stance grounded in relevant treaty texts and negotiating history, while the EU employs scientific evidence and evolutionary interpretation, and Indonesia relies on historical argumentation based on original negotiating intentions. Beyond legal arguments, China strategically articulates core political concepts such as ecological civilization, common but differentiated responsibilities, and a community of shared future for humankind to construct its identity as a responsible developing country committed to multilateral cooperation and the South-South solidarity. While China’s legal formalist approach achieves internal coherence, its extensive use of dialogic contraction risks procedural isolation and may undermine its green leadership credibility among vulnerable states. The EU’s evolutionary interpretation aligns with climate justice but faces legitimacy challenges in the Global South due to unilateral measures. While defending institutional order, Indonesia may underestimate the value of advisory opinions as legal relief for small island states (SIDS). Policy implications suggest that revisiting the application conditions of common but differentiated responsibilities and balancing soft law mechanisms with judicial evolution are essential for advancing equitable and effective ocean governance in the context of climate change.
The Wyrtki Jet plays an important role in the tropical Indian Ocean circulation, yet its variability near the eastern boundary was observed scarcely. In this study, a strong Wyrtki Jet event in the spring 2014 is analyzed using satellite-tracked surface drifter trajectories combined with the mooring data in the eastern Indian Ocean. The observed maximum zonal velocity reaches 1.2 m s-1, twice as much as the spring jet climatology. Following the strong spring jet, another eastward jet with velocity of 0.9 m s-1 is observed in July, when the seasonal zonal currents typically flow westward. The LICOM ocean general circulation model, which successfully simulates the observed zonal currents in the eastern Indian Ocean in 2014, is used to investigate the dynamics of the Wyrtki Jet event. Decomposed equatorial waves from the model simulation show that the 2014 event is dominated by wind-driven downwelling Kelvin waves and the reflected upwelling Rossby waves of earlier wind forcing in the central and eastern basin. Reconstructed zonal currents from the wave coefficients suggest that the second baroclinic-mode Rossby waves reflected from the Kelvin waves dominate the strong spring Wyrtki Jet, with higher-order baroclinic modes contributing more than 30% of the velocity amplitude. The eastward current in July 2014 is dominated by an intraseasonal wind-driven Kelvin wave. The disclosed dynamics highlight the important roles of the boundary reflections and higher-order modes in modulating the ocean circulation in the eastern Indian Ocean near the boundary.
The blue-green damselfish, Chromis viridis (Cuvier, 1830), is widely distributed across Indo-Pacific coral reefs and is among the most heavily traded marine ornamental fishes. Recent molecular studies have suggested the presence of cryptic diversity within the C. viridis complex, but species boundaries remain unresolved. Multilocus phylogenetic analyses incorporating three mitochondrial markers—cytochrome c oxidase subunit I (COI), cytochrome b (cytb), and the mitochondrial control region (D-loop)—and two nuclear markers, recombination-activating gene 1 (RAG1) and recombination-activating gene 2 (RAG2), were performed to assess lineage diversification within the Chromis viridis species complex. Specimens collected from the Lakshadweep Archipelago and the Gulf of Mannar, India, formed a distinct and well-supported lineage that was clearly separated from C. viridis sensu stricto and other congeners in phylogenetic reconstructions and genetic distance analyses. Multiple species-delimitation approaches consistently supported the recognition of this lineage as an independently evolving taxon, and morphometric analyses revealed corresponding differences in body proportions and meristic characters. Based on the concordance of molecular and morphological evidence, a new species, Chromis veneta sp. nov., is herein described from the Indian Ocean. The new species differs from C. viridis in having a relatively elongate body, narrower caudal peduncle, distinctive body pigmentation, yellowish to orangish distal fin margins, and a deeply forked caudal fin with elongate lobe tips. Additional diagnostic features include differences in dentition, gill-raker counts and sagittal otolith morphology. The discovery of C. veneta sp. nov. highlights underestimated diversity within the C. viridis complex and underscores the importance of integrative taxonomy in revealing cryptic reef-fish diversity.
In kelp aquaculture, higher nitrate concentration increases productivity, and water temperatures within a favorable range promote kelp survival. In specific oceanic regions these environmental conditions can be produced by artificial upwelling. This work explores whether wave-powered artificial upwelling can modify local environmental conditions to enhance kelp mariculture productivity. A coupled physical-biogeochemical modeling feasibility study was developed using multiyear empirical oceanographic data of temperature, nitrate concentrations, and wave conditions at an ocean case study site in the Gulf of Maine. The study is limited in its approach where mixing conditions are assumed to be ideal, and horizontal advection is assumed to be negligible (or periodic within a much larger kelp farm). The model estimates that wave-powered upwelling can decrease the water temperature by an average of 1.0 ± 0.15 °C from June through October, and increase nitrate concentration by an average of 0.1−1.1 µmol L−1 from June through September depending on parameter uncertainties within a simplified model kelp farm. Additional analysis of farm-scale boundary conditions suggests that the spatial distribution and degree of mixing upwelled water strongly influences the extent of nitrate increase and cooling within kelp farms. The environmental changes in the example kelp farm due to wave-powered upwelling are then applied to a validated kelp growth model with empirical surface current magnitudes and irradiance data, producing an estimate of 0.9−0.0+1.1 DMT ha−1 yr−1 (or approximately 9.5%−10%+1.6%) of additional kelp grown. The kelp growth model assumes that nitrate is the only limiting nutrient in kelp growth, and has some other limitations. This framework facilitates further investigation of wave-powered upwelling as a scalable ocean-based strategy for sustainable kelp aquaculture. Combined, these findings suggest that wave-powered artificial upwelling may enhance kelp productivity under nutrient-limited and seasonally warm conditions in temperate marine ecosystems.
Marine ecological environmental protection constitutes a core component of the United Nations Sustainable Development Goals, and it plays a pivotal role in advancing the development of a global marine community with a shared future.This study adopts the PMC index model to systematically analyze the evolutionary characteristics of 30 marine ecological environmental protection policies issued by the Chinese government between 2015 and 2024, aiming to offering valuable insights for national marine ecological environment protection efforts. The study shows that: (1) The mean value of the PMC index of China’s marine ecological environment protection policies reaches 6.243, which achieve outstanding performance in goal consistency, resource allocation, implementation efficiency and social impact. (2) China’s marine ecological environment protection policies are relatively excellent in areas such as policy evaluation, policy focus, policy instruments, policy characteristics, policy functions and policy areas, but they exhibit weaknesses in policy scope, policy timeliness and issuing institutions. (3) There are significant differences in the effectiveness of policy implementation. The case of Fujian Province further highlights the critical role of policy text design in marine ecological environment governance.This study provides actionable theoretical references for advancing the delivery of the United Nations Sustainable Development Goals and facilitating global marine ecological governance worldwide.
