中华人民共和国国家海洋局

Defect engineering in metal-organic frameworks (MOFs) is critical for enhancing their adsorption performance. Herein, a "large-pore" UiO-66-SH (LP-UiO-66-SH) was successfully synthesized by introducing the monodentate ligand 3-amino-4-hydroxybenzoic acid (3,4-AHBA) into UiO-66-SH. This strategy generates ligand defects and creates opens metal vacancies, thereby enhancing the porous structure and the density of active sites. Consequently, LP-UiO-66-SH exhibited significantly superior adsorption kinetics and capacity compared to micro-UiO66-SH, achieving a maximum Hg(II) uptake of 1180 mg g- 1 (versus only 560 mg g- 1 for micro-UiO-66-SH under comparable conditions) and rapidly reducing the Hg(II) concentration in seawater to the drinking water standard (0.002 mg L- 1) within 8 min. DFT and molecular dynamics (MD) simulations further revealed that S-H, -NHS and -OH groups cooperatively participate in Hg(II) binding, while the presence of a porous architecture significantly improved adsorption kinetics across a wide range of initial Hg(II) concentrations. This study provides a defect-engineering strategy for designing efficient porous adsorbents for mercury-contaminated water remediation and, through combined experimental and theoretical analyses, elucidates the intrinsic coupling mechanism between defect-induced binding sites and ion transport within the engineered framework.

Ulva prolifera, the principal driver of green tides worldwide, can form massive blooms that severely disrupt coastal ecosystems and cause substantial economic losses. However, its global potential distribution and responses to future climate change remain poorly resolved. Here, we used a MaxEnt species distribution model to simulate the current and future (SSP5-8.5) global suitability patterns of U. prolifera, achieving high predictive performance (AUC = 0.982 ± 0.005). Our results indicate that three groups of environmental factors jointly constrain its potential range: minimum iron concentration acts as the fundamental limiting factor for basic growth; minimum primary productivity, maximum dissolved oxygen, and maximum chlorophyll regulate the development of high-biomass blooms; and minimum temperature sets the thermal boundary for high-latitude distribution and overwintering. Present high-suitability zones are markedly clustered along mid- to high-latitude continental shelves (Moran’s I = 0.727, p < 0.001). Under the SSP5-8.5 scenario, warming relaxes thermal limitations at higher latitudes and drives poleward expansion of suitable habitats, whereas cold-current regions remain unsuitable due to persistently low temperatures. In contrast, most open-ocean areas show limited change in suitability owing to sustained iron limitation and nutrient scarcity. These findings elucidate the dominant environmental controls and climate responses of U. prolifera suitability and provide a scientific basis for green-tide prevention and marine ecological risk assessment in a warming ocean.

Abstract This study describes the migration law of pollutants in the complex hydrodynamic environment of the pearl river estuary, and then effectively prevents and controls the pollution problem in the greater bay area. On the basis of the traditional finite-volume coastal ocean circulation model (FVCOM), it combines seasonal runoff correction, dynamic wind stress driving, and seasonal dependent diffusion coefficient parameterization scheme. The study presents an Euler passive tracer module to construct a three-dimensional baroclinic hydrodynamic-pollutant coupling model that can distinguish barotropic and baroclinic conditions. An unstructured triangular grid is used to realize the study area’s fine division. Combined with the collaborative application of the Euler module and Delft3D pollutant transport model, the migration and diffusion process of dissolved pollutants is simulated. The results reveal that under the strong wind in winter, the half-exchange time of pollutants is only 2–3 d. The diffusion path is highly consistent with the wind direction (correlation coefficient is 0.92), and the pollutants are transported to the sea quickly. However, due to the baroclinic effect caused by thermal stratification in summer, pollutants form a detention zone near the shore, and the half-exchange time is extended to 5–7 d; meanwhile, the influence of wind fields is obviously weakened. The model verification shows that the improved FVCOM’s coefficient of determination values in winter and summer are 0.963 and 0.933, respectively; they are superior to those of the traditional FVCOM. This study provides theoretical support for the precise management of estuarine waters and helps to formulate more targeted environmental management measures.

Phytoplankton are primarily confined to the sunlit epipelagic zone, yet intact algal cells persist in the ocean’s mesopelagic twilight zone where light is minimal. However, their survival strategies in the deeper ocean remain unknown. Here, we isolate Chaetoceros sp. DS1 from 1000 m depth and reveal its survival mechanisms under prolonged darkness and high pressure, including membrane lipid remodeling and enhanced antioxidant defenses. Importantly, DS1 maintains a latent photosynthetic reserve that activates upon exposure to dim blue light and higher pressure typical of the twilight zone, enabling photosynthesis and nutrient uptake. It exhibits metabolic flexibility by utilizing stored carbon in darkness and assimilating organic carbon under dim light. Global meta-omics data show widespread, transcriptionally active Chaetoceros -like diatoms in the twilight zone, expressing blue-light sensors and protein synthesis genes. These findings identify the ocean twilight zone as a previously overlooked niche for metabolically active phytoplankton, expanding understanding of deep-ocean microbial ecology and carbon cycling. ### Competing Interest Statement The authors have declared no competing interest. Natural Science Foundation of China, 42188102, 42476116, 42476115, 42576100 Global Ocean Negative Carbon Emissions (ONCE) Project Fundamental Research Funds for the Central Universities