Numerical simulations of ocean surface waves in the China Seas

Distribution characteristics of emerging contaminants and microbial communities in Bohai Sea sediments.

WaveCastNet-C: Forecasting the significant wave height in the China Sea with a fully convolutional neural network

Accurate estimation of vertical aerosol extinction coefficient (AEC) profiles is essential for lidar retrievals and radiative transfer modeling, yet it remains challenging over marine regions due to complex structural variability. To address this, we developed an analytical two-layer AEC profile model for the China Seas (CS) using CALIPSO observations collocated with the ERA5 meteorological data (2007-2021). By applying height-resolved hierarchical clustering (HC) from 0.18 to 12km, we identified two distinct vertical regimes: a well-mixed planetary boundary layer (PBL) and an overlying free-tropospheric layer (FTL). The model parameterizes the PBL AEC using a Gaussian function to capture turbulent mixing, while representing the FTL with an exponential decay function to characterize dilution processes. Optimized via a genetic algorithm (GA), the model exhibits excellent agreement with CALIPSO observations across the Bohai-Yellow Sea (BYS), the East China Sea (ECS), and the South China Sea (SCS), achieving R2>0.9 and RMSE<0.01km-1. This physically grounded and computationally efficient approach provides a robust and accurate solution for marine AEC estimation.

Sea-surface chlorophyll-a concentration (Chl-a) is a core indicator reflecting phytoplankton biomass and marine ecological conditions. Its spatiotemporal variation patterns are closely related to environmental changes and human activities, especially in coastal waters around heavily populated areas, e.g., the Bohai Sea in China. Benefiting from long time-series ocean-color (i.e., Chl-a provided by Aqua-MODIS) multi-source merged sea surface temperature (SST) and wind speed (i.e., ERA5) and dissolved inorganic nitrogen concentration (DIN) data, this study investigated the long-term variation characteristics of Chl-a in the Bohai Sea and its influencing factors during the period of 2003 to 2022. After rigorous quality control and data reconstruction, this study analyzed the interannual, seasonal, and spatial variation patterns of Chl-a in the Bohai Sea across five ecological functional subregions (Bohai Bay, the Qinhuangdao coast, Liaodong Bay, Laizhou Bay, and the central Bohai Sea), and explored the influence of SST, wind speed, and DIN on variations in Chl-a. The results showed that the spatial distribution of Chl-a in the Bohai Sea exhibited a significant coastal–offshore gradient, with higher concentrations in coastal bays and the Qinhuangdao coast and lower concentrations in the central Bohai Sea. Temporally, despite a long-term trend of first increasing and then decreasing with a peak around 2011, Chl-a underwent a significant regime shift around 2015. After the shift, the average concentration decreased by 0.36 mg/m3 compared with that before the shift. On a seasonal scale, the average Chl-a concentration over the whole Bohai showed the largest decrease in summer (−0.65 mg/m3) and the smallest decrease in winter (−0.21 mg/m3), with contrasting changes among subregions: the Qinhuangdao coast had the most significant decrease (−1.54 mg/m3), while Laizhou Bay remained basically stable. Driver mechanism analysis indicated that Chl-a in the Bohai Sea was significantly negatively correlated with SST (r = −0.51, p = 0.022) and significantly negatively correlated with wind speed (r = −0.77, p &lt; 0.01). Furthermore, both SST and wind speed have undergone significant regime shifts toward a warmer and a windier state, respectively. The timing of these climatic shifts coincided with or preceded the Chl-a regime shift, which may help suppress phytoplankton blooms and maintain lower Chl-a levels. In addition, the surface DIN concentration in Bohai Bay decreased by 23.6% after the Chl-a regime shift, indicating a reduction in nutrient input may be responsible for the decrease in Chl-a in this region. The research results reveal the long-term variation patterns and multi-factor synergistic regulatory mechanism of Chl-a in the Bohai Sea, providing a scientific reference for red-tide monitoring and early warning as well as regional ecological environment management in the Bohai Sea.

ENSO shapes salinity regimes and fish migration in the China Seas

Current wind energy planning in the China Seas and adjacent waters generally focuses on wind speed or wind power density (WPD), yet lacks sufficient understanding of the long-term climatic evolution patterns and climatic driving mechanisms of effective wind speed occurrence (EWSO) and its correlation with climate oscillations. Based on the ERA5 10 m sea surface wind reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) and multiple key climate index datasets from 1941 to 2020, this study systematically analyzed spatiotemporal distribution characteristics, long-term variation trends, and correlations with climate oscillations of EWSO in the China Seas and adjacent waters. The results indicated the following: (1) There are discrepancies between the distribution of EWSO and mean wind speed. (2) Over the past 80 years, EWSO across the study area has shown an overall significant increasing trend with pronounced regional disparities, among which the Yellow–Bohai Sea area has exhibited a significant decreasing trend. (3) The interannual variability of EWSO is regulated by climate oscillations such as ENSO. This study demonstrates that incorporating EWSO as an independent indicator separate from wind speed into the wind energy resource assessment system is crucial for identifying offshore wind power generation risks and more accurately evaluating the actual operational duration of wind farms in China’s offshore waters and adjacent sea areas. The correlation between EWSO and climate oscillations such as ENSO provides an important scientific basis for improving seasonal prediction models of wind energy resources.

In this study, we conducted molecular identification and complete mitochondrial genome annotation of isopod parasites isolated from mud crabs (Scylla paramamosain) in the China Sea. The specimen was identified as Portunion sinensis, a recently described species of the family Entoniscidae. P. sinensis is characterized by an anterior thorax positioned vertically and posterior ventral processes directed backwards; the female's marsupium is formed by the close adhesion of oostegites to the host membrane; the first oostegite is differentiated into three parts; the pleopoda have well-developed lamellar and pleural lamellae; and two ventral ovarian processes are present along with a pair of dorsal processes. The complete mitochondrial genome of the parasite is 14,603 bp in length, containing 35 genes (13 protein-coding genes, 20 transfer RNAs, and 2 ribosomal RNAs) as well as a putative control region (CR) located between the cob and nad1 genes. This study represents the initial characterization of the mitochondrial genome of P. sinensis. These findings provide molecular validation of its status as an independent species and lay the groundwork for the future identification of parasites within the genus Portunion. These data provide a necessary molecular reference for future research into the systematics and evolutionary history of decapod-infesting parasites.

Occurrence and prioritization of hydrophobic pollutants in China's coastal marine biota.

Jan Cornelis Christiaan Loman (1856–1929) was a major contributor to our knowledge of sea spiders (Arthropoda, Pycnogonida) and to the collections of the Naturalis Biodiversity Center (NBC), Leiden. Loman worked on Pycnogonida material from various geographic origins, including southern Africa, the Antarctic Peninsula, Arctic seas, Southeast Asia, the Atlantic, Australia, the China Sea, Japan, and the Mediterranean Sea; he notably participated in the taxonomic study of samples from the Siboga Expedition, the Prince Albert I of Monaco expeditions, and the Swedish Antarctic Expeditions. In total, Loman described 54 sea spider species and six sea spider genera; 48 and three, respectively, are still regarded as valid today. In the present work, we aim to summarise Loman’s outstanding contribution to sea spider taxonomy by listing all species he reported or described. We recovered a total of 162 records in NBC, 133 of which correspond to type material, including 19 holotypes and 37 syntypes. We further sought out all Loman’s Pycnogonida material curated at NBC and located additional type material housed in institutions worldwide.

In the context of increasingly scarce global marine spatial resources, multi-use (MU) of the sea has emerged as an effective pathway to promote sustainable marine development, representing a growing trend in the utilization of marine resources. In this study, we reviewed the evolution of MU of the sea in China, dividing its development into three stages: surface use, exploratory three-dimensional use, and systematic three-dimensional development. We further categorized MU of the sea into three types: “temporary” “three-dimensional” and “coexistence”. We proposed a evaluation methodology for MU of the sea, including the construction of a functional compatibility assessment matrix for sea-use projects. On this basis, we introduced China’s practice of three-dimensional layered rights to the use of sea areas. We elaborated on the latest progress in MU of the sea in China from the perspectives of feasibility analysis and approval methods for right confirmation, definition of three-dimensional spatial scope, and advances at the provincial level. The results of this research contribute to the improvement of marine spatial planning and the enhancement of sustainable marine development.

Organochlorine pesticides (OCPs) in the sediment of the Bohai Sea in China: Slow phasing out but risk remaining.

Effects of climate change on the metabolic ecology of small yellow croaker (Larimichthys polyactis) based on dynamic energy budget (DEB) model.

Impact of human activities on rare earth elements in coastal regions: Anthropogenic gadolinium sources, budget, and transport.

Abstract Caprellidae are distributed worldwide and have significant importance in biological evolution, ecosystems, and fisheries. However, there is a lack of research on the family in the China seas. Caprella algaceus Vassilenko, 1967, previously reported from Russia, Japan and Korea, is now recorded for the first time from the P.R. China. Morphologically, the present specimens differ from the original description by having shorter body lengths and the pereonite 1 shorter than the head, instead of longer or subequal. These two morphological differences were generally taken as intraspecific variations of development during growth, or sexual differentiation, in caprellids. The distinguishing morphological differences were observed in four characters, including the number of flagellar articles in antenna 1, the attachment position as well as the shape of gnathopod 2, and the ratio of the length of pereonite 1 and the head, within C. algaceus as reported herein. A mitochondrial gene ( COI ) was used to reveal all those differences originating from sexual dimorphism, or ontogenetic variation.

239+240Pu chrono-marker and migration in sediment cores in China Sea.

Abstract Borneo is a key piece of the regional tectonic puzzle of southeast Asia and a unique location to study subduction termination, particularly in the north. The tectonic history of Sabah in northern Borneo includes elements of five different subduction events: (a) westward Triassic Palaeo‐Pacific (∼240–200 Ma); (b) southward Cretaceous proto‐South China Sea (PSCS) (92–86 Ma); (c) southward Late Eocene to Early Miocene (∼40–20 Ma) Proto‐South China Sea; (d) northwestward Celebes Sea (∼17–9 Ma); and (e) southeastward Middle Miocene Sulu Sea (∼15–10 Ma) subduction. Anti‐clockwise (∼45°) rotation of Borneo and Neogene (∼23–5 Ma) uplift and subsidence events preceded Late Miocene‐Early Pliocene exhumation and emplacement (7.8–7.2 Ma) of the 4,095 m high Mt. Kinabalu granite pluton. We utilize the northern Borneo Orogeny Seismic Survey seismological data set to calculate teleseismic receiver functions and constrain crust and upper mantle discontinuities beneath Sabah using common conversion point migration imaging. Mid‐crustal and Moho discontinuities occur beneath most of Sabah at 22–25 and 30–40 km depth, respectively, but major lateral variations delineate lithospheric boundaries that appear associated with surface ophiolites, Mt. Kinabalu granite, and sedimentary depocenters. We show evidence for an uppermost mantle slab remnant beneath Sabah in the form of a gently westward‐dipping, 75–100 km wide, discontinuity at 45–55 km depth, likely composed of oceanic crust, its lithosphere detached, and associated with Celebes Sea subduction. Sabah geology, tectonics, uplift and subsidence are reexamined in light of the new lithosphere images, revealing Sabah and post‐subduction tectonics in unprecedented detail.

Sea level budget in the China Seas over 2005–2023

Simultaneous determination of 90Sr and Pu isotopes in marine biological samples.

Nemopilema nomurai is a species of common large toxic jellyfish in China seas, and its tentacle tissues contain various types of nematocysts. However, the correlation between the morphology and function of nematocysts still remains unclear. In this study, we first obtained two monomorphic nematocysts with high-purity from N. nomurai, namely Anisorhizas and O-isorhizas, by density gradient centrifugation: the Anisorhizas is small and rod-shaped and the O-isorhizas is larger and spherical. Upon deionized water stimulation, O-isorhizas exhibited a stronger discharge capability than Anisorhizas. The nematocyst contents of Anisorhizas (AnC) and O-isorhizas (OnC) were extracted separately, and their composition and bioactivities were analyzed simultaneously. The protein bands by SDS-PAGE revealed similar distributions in AnC and OnC, except that the protein band distribution in OnC was more extensive. OnC showed stronger cytotoxicity, hemolytic activity, metalloprotease activity, and serine protease activity than AnC. In contrast, AnC exhibited a higher antioxidant activity and significant proinflammatory activity. Both AnC and OnC exhibited antimicrobial activities against certain marine pathogenic Vibrios. These results suggest that O-isorhizas, with the larger capsule capability, stronger discharge ability and toxicity, likely plays a major role in inducing toxic effects and tissue damage, while Anisorhizas, being smaller and less toxic, may undertake preferentially other functions, such as synergistic predation, environmental stress adaptation, and energy balance maintenance. This study provides insights into the morpho-functional relationship between various types of nematocysts, and also lays a foundation for further exploration of the functional diversity of nematocysts and the mechanisms underlying jellyfish envenomation.