China Sea Area Research Articles

A dataset of thunderstorm features of the FY-2E full-disc observation area from 2010 to 2018

Thunderstorm clouds yield lightning discharges and are often accompanied by damaging weather; therefore, they are important concerns for weather monitoring and forecasting. At present, the research on the thunderstorm activity in China is deficient; and available thunderstorm cloud datasets with high temporal-spatial resolution and big spatial coverage are rare. We established the thunderstorm feature dataset (TFD) by using the black body temperature (TBB) and the cloud classification (CLC) products from the Fengyun-2E (FY-2E) satellite and the lightning location data from the World-Wide Lightning Location Network (WWLLN). Thunderstorm cloud is defined in accordance with the criterion that at least one WWLLN lightning is in the area with TBB ≤ −32°C or its fitted ellipse. We obtained the parameters including time, location, structure, and lightning activities to prepare the TFD. This dataset extends from 2010 to 2018, with a temporal resolution of 1 hour and wide spatial coverage of the FY-2E full-disc observation area, especially including the mainland and adjacent sea areas of China. This TFD can play an important role in the study of thunderstorm activities.

Paleoenvironmental reconstruction of the Eocene sediments in the Baiyun sag of the Pearl River Mouth Basin

The Baiyun sag of the Pearl River Mouth Basin has become a focus for deepwater exploration with the highest hydrocarbon potential in northern South China Sea. The Eocene organic-rich mudstones are the main source rocks in the Baiyun sag, and the evolution of their depositional environment remains unclear. Based on the core and geochemical data, we investigated the depositional environments of the Eocene Wenchang and Enping sediments in the Baiyuan sag and revealed the sedimentary environment influences on the formation of the source rocks in the study area. The results indicate that the sediments of the Wenchang and Enping formations were deposited in dysoxic to oxic environments. Moreover, according to the concentrations of salinity-sensitive trace elements, and δ13C (-10.9‰ to -7.2‰, average -8.58‰) and δ18O (-18.4‰ to -14.5‰, average -17.1‰) values of carbonate cement in the sandstone samples, the Wenchang and Enping formations were in fresh water to brackish water conditions during their deposition, with increasing salinity from bottom to top, which suggests that the two formations were mainly deposited in lacustrine environment and the Enping formation experienced a relatively extensive lake transgression. The vertical variations of geochemical characteristics suggest that the Wenchang and Enping formations were deposited under a semi-arid/warm condition and all Eocene sediments experienced mild to moderate chemical weathering, relatively large detrital input and stable paleowater depth. Both primary productivity and preservation conditions played essential roles in controlling the enrichment of organic matters in the Baiyun sag, and the preservation conditions resulted from the restricted water setting. The present work provide a comprehensive analysis of depositional environments based on the abundance of high-resolution geochemical data. The results obtained reveal the dominated factors controlling organic matter enrichment in the Baiyun Sag of the Pearl River Mouth Basin. Those findings are not only significant for understanding the region’s paleogeography, but also provide guidance for future profitable oil and gas exploration in the northern South China Sea and other similar areas.

PASAR IKAN BERSIH SUKADANA, KABUPATEN KAYONG UTARA

North Kayong Regency is in the fishing area in WPP 711 which is the cumulative management area of the Karimata Strait, Natuna Sea and South China Sea areas, which allows this district to have large production potential in the fisheries sector. The potential of the fisheries sector in the large North Kayong Regency has not been fully utilized optimally due to the low availability of facilities and infrastructure for handling catches. As the capital of a district that has high potential for fish production, Sukadana does not yet have adequate catch handling facilities, so it is necessary to have facilities for fishermen and consumers, especially for the people of North Kayong Regency. The design of the Sukadana Clean Fish Market, Kayong Utara Regency aims to facilitate both in the food and economic sectors for the people of North Kayong Regency. The method used is the glass box method, which goes through several stages starting from collecting data related to fish market issues, identifying problems in the fish market, then obtaining theories related to clean fish markets as fish market standards based on relevant regulations, formulating design concepts, conducting analysis , then make pre-design drawings and technical drawings (DED). Through the design concept of a hygienic fish market in Sukadana District, Kayong Utara Regency, a fish market combines traditional market systems and modern markets which is presented in an open stall and a closed stall. The fish market with this concept was created by considering the needs and habits of the surrounding community which functions as a forum or place for buying and selling transactions as well as a place for processing fish and seafood.

The Indo-Pacific Context : Maritime Security Challenges And Diplomacy Of Asean Countries

The Indo-Pacific region is considered strategic considering that there are intersections in international trade routes in it. Meanwhile, the strategic value as a geopolitical center is emphasized by the presence of strong countries such as the United States, China, India, Australia, Japan, as well as ASEAN countries. Based of the problem that has been described, the objective of this article is to examine the strategies and diplomatic efforts of ASEAN countries in dealing with maritime security threats in the Indo-Pacific Region. The study used qualitative methods with descriptive research design. This research through the Zoom Meeting application by inviting representative speakers from Universitas Pertahanan Malaysia. The activity will be held on 28 June-2 July 2021. Theoritical framework in this article using maritime security concept, maritime diplomacy concept, and Indo-Pacific Concept. The conclusion is the feud between China and the United States in the Indo-Pacific region, especially the South China Sea has the potential to disrupt regional stability and security. Maritime security related to undisturbed shipping traffic and communications is an effort that the United States is guarding. China's presence in the South China Sea area threatens the interests of the United States regarding sea traffic which will have an impact on the global economy and its country if no action is taken. Countries in Southeast Asia see this problem as something that must be resolved. The presence of AOIP is expected to be able to help resolve existing problems regarding actions that are carried out individually by ASEAN member countries.

Carbon emission pinch analysis for shipping fuel planning considering multiple period and fuel conversion rates

In the context of achieving carbon neutrality, reducing CO2 emissions has become an essential task for many countries and poses challenges for various industries. With global trade, the shipping industry is overgrowing, bringing economic benefits but also significant CO2 emissions. To achieve the goal of carbon neutrality, the fuel mix of ships needs to be planned appropriately. As an extension of the base method of Carbon Emission Pinch Analysis, this study develops a new Carbon Pinch Point analysis method for shipping fuel planning. Optimising the energy mix of ships in different period is used to reduce CO2 emissions from shipping fuels and achieve the set emission reduction targets. Taking the Zhoushan sea area in China as an example, emission reduction targets are set in three period with a five-year period from the national policy level. The first period (2020–2025) achieves a 14.5% reduction relative to 2020; the second period (2025–2030) achieves a 32.2% reduction relative to 2020; and the third period (2030–2035) achieves a 57.2% reduction relative to 2020. Each period is divided into Scenario 1 (without heat loss), and Scenario 2 (with heat loss), and two options are developed for each scenario by constraining different low-carbon fuels. The study shows that it is more economical to use LNG as an alternative fuel in the first period, requiring an additional 457.74 kt of LNG in Scenario 1 and 225.26 kt of LNG in Scenario 2. Using biodiesel as an alternative fuel in the second period is more economical, requiring an additional 343.55 kt of biodiesel in Scenario 1313.04 kt of biodiesel in Scenario 2. The use of biodiesel as an alternative fuel in the third period is more economical, requiring an additional 371.73 kt of biodiesel in Scenario 1 and 466.23 kt of biodiesel in Scenario 2.

Potential Suitable Area of Invasive Species Cryptomonas sp. under Climate Change Scenarios in China Sea Areas

Alien invasive algae along with ship ballast water have posed a serious threat to China’s marine ecological security. A clear understanding of the geographical distribution of invasive species and their response to climate change can provide a scientifi c basis for their prevention and control. In this study, combined with environmental variables and distribution data, MaxEnt was used to predict the potential geographical distribution and change trend of Cryptomonas sp. in the four major sea areas of China in current, 2040s (2031-2050) and 2090s (2081-2100), reveal the dominant environmental factors affecting the geographical distribution, analyze the migration trends of centroids the highly suitable area, and clarify the key control sea areas. Results showed that: 1) The most important environmental variable affecting the geographical distribution of Cryptomonas sp. was the Temperature. Range (bio24). 2) Under current climate condition, the suitability index of Cryptomonas sp. in the whole sea area of the Yellow Sea, the northern sea area of the East China Sea, and the corresponding sea areas of Jiaxing, Ningbo, Dongying, Weifang and Zhangzhou, and special attention should be paid to the prevention and control of Cryptomonas sp.. 3) Under the scenarios in 2040s (2031-2050) and 2090s (2081-2100), the total suitable area and highly suitable areas of Cryptomonas sp. in the four sea areas of China showed an increasing trend. 4) Under climate change scenarios in 2040s and 2090s, in the Yellow Sea, the centroid of the highly suitable area of Cryptomonas sp. would generally move to the southeast or southwest. In the Bohai Sea and the East China Sea, the centroid showed a trend of moving to different latitudes and directions under different scenarios. In the Bohai Sea, the centroid showed a trend of moving to the north. These moving trends indicated that Cryptomonas sp. may adapt to climate change by changingtheir distribution areas.

Green Efficiency Measurement of Seaweed Culture in China under the Double Carbon Target

Seaweed culture is of great significance in giving full play to the function of marine carbon sequestration and strengthening the protection and repair of the marine ecosystem. Its green efficiency measurement can provide China with a means for a global low-carbon economy. From the ecological perspective of net carbon sink, this paper selects three indexes: input, expected output and unexpected output. The total carbon sink and carbon emissions are included in the evaluation index system of green efficiency of seaweed culture in China. The green efficiency of seaweed culture in China from 2008 to 2020 is calculated by the super-SBM model. Through the redundancy rate of input and output, the influencing factors of net carbon sink output of seaweed culture are put forward. According to the empirical calculation results and influencing factors of green efficiency, the countermeasures and suggestions for green seaweed culture in China under the dual-carbon target are put forward. The results showed that: (1) the net carbon sink and green efficiency level of seaweed culture in China showed an overall growth trend, and there was a lot of room for growth in economic and ecological benefits; (2) influenced by index factors and non-index factors such as marine resource economy and planning, there are differences in seaweed culture and green efficiency in the three major sea areas of China; (3) the indexes of green efficiency of seaweed culture in different study areas are different; and (4) the improvement of green efficiency can promote the Chinese seaweed culture industry. Green technology progress effect, structure effect, and input–output scale effect are the main influencing mechanisms of green efficiency of seaweed culture. It is suggested that in the future, we should optimize the structure of seaweed culture, innovate seaweed culture technology, improve carbon sink trading policy and strengthen the training of carbon sink talents. This will accelerate the realization of the goal of green and double carbon seaweed culture and promote the global low-carbon economy.

Depth distribution of Moho model and tectonic patterns in South China Sea and adjacent areas

This study aims to investigate the depth distribution of Mohorovicic discontinuity (Moho) and its relationship with the tectonic pattern of the South China Sea and adjacent areas. To achieve this, the spatial characteristics of the full tensor gravity gradient data are analyzed to identify 17 large and deep faults and to divide the study area into 9 tectonic units with distinct geological structures. Using a three-dimensional (3D) interface inversion method, the Moho depth is determined, constrained by the Moho depth information obtained from sonar-buoy detection and submarine seismograph detection profiles. By analyzing the relationship between the distribution characteristics of Moho and tectonic units, the study summarizes the trend, relief, gradient of Moho, and crustal properties in the study area. Additionally, the seismically constrained Moho undulation combined with the gravity data, gravity gradient anomalies and unconstrained 3D correlation imaging are employed to study the crustal structure of the South China Sea, investigate the vertical and horizontal changes of the crustal structure, and reveal the large-scale crustal and regional structure of the South China Sea. Through the coupling analysis of shallow and deep structures, the study reveals that the gravity gradient anomalies and 3D correlation imaging are consistent with the variations of the Moho depth, indicating the presence of a trench-island arc-back arc basin system and the distribution of continental crust, oceanic crust, and transitional crust in the South China Sea.

Pertanggungjawaban Negara China Akibat Pencemaran Di Laut China Selatan Dalam Prespektif Hukum Lingkungan Internasional

Introduction: One of the satellite imagery analysis companies, Head Of Simularty, based in the United States, found that there has been pollution to the marine environment in the South China Sea area, precisely in the Spratly Islands, namely the coral island of Whitsun Reef which is still part of the Exclusive Economic Zone of the Philippines.Purposes of the Research: Aims to find out and analyze the regulation of international law on pollution in the South China Sea and to find out and analyze the form of accountability of the Chinese State due to marine pollution carried out under international environmental law. Methods of the Research: This legal research uses normative juridical research, case approach, statutory approach, and conceptual approach, primary and secondary legal materials, legal material procedures using primary legal materials which are then associated with secondary legal materials and processing and analysis of legal materials using qualitative descriptive analysis.Results of the Research: The results showed that China had violated international environmental law obligations as stipulated in the Stockholm Declaration 1972, Rio Declaration 1992, UNCLOS 1982 and MARPOL 73/78. Furthermore, marine pollution carried out by the State of China in the territory of the Exclusive Economic Zone of the Philippine State has opposed the provisions of international environmental law as stipulated in the 1972 Stokcholm Declaration and UNCLOS 1982 which states that it prohibits any country from taking acts of pollution against the environment against both its own territory and in the jurisdiction of other countries. Therefore, it is necessary to have accountability efforts that must be carried out due to the pollution actions carried out.

Non-Claimant States’ Perspectives on the South China Sea Dispute

The problem in the South China Sea is becoming increasingly complex because other parties also have strong regional interests. The other party was later called a non-claimant state in the South China Sea area. Non-claimant states ensure that international law of the sea is enforced in any part of the sea on the planet to guarantee safety and freedom to transport commodities with high economic value. These non-claimant states generally oppose China's actions that do not comply with the agreed UNCLOS. This juridical normative research presents the legal basis for the actions of non-claimant states in the South China Sea region based on relevant literature. This study describes the basis of international law and the interests and policies of non-claimant states such as Indonesia, the USA, the UK, Australia, the EU, Japan, and India over the South China Sea region.

Cenozoic Subsidence History of the Northern South China Sea: Examples from the Qiongdongnan and Yinggehai Basins

The Qiongdongnan and Yinggehai Basins are important petroliferous basins. To study the Cenozoic subsidence characteristics of these two basins, their controlling factors, and their implications, we studied the basins’ subsidence characteristics via one-dimensional, two-dimensional, and holistic subsidence. Then, we compared the basins’ subsidence characteristics based on the evolution of several particular geological processes that occurred in the South China Sea (SCS) and adjacent areas. The results indicated that the change in the holistic subsidence of both basins occurred episodically. In addition, the subsidence in these two basins differed, including their subsidence rates, the migration of the depocenters, and the changes in the holistic subsidence. The dynamic differences between the two basins were the main factors controlling the differences in the subsidence in the two basins. In the Qiongdongnan Basin, the subsidence characteristics were primarily controlled by the mantle material flowing under the South China Block in the Eocene and the spreading of the SCS from the Oligocene to the Miocene. In the Yinggehai Basin, the subsidence characteristics were primarily controlled by the coupling between the uplift of the Tibetan Plateau and the strike-slip motion of the Red River Fault before the Early Miocene and by only the effect of the strike-slip motion of the Red River Fault from the Middle Miocene to the Late Miocene. Since the Pliocene, the subsidence characteristics of both basins have been principally controlled by the dextral strike-slip motion of the Red River Fault. The major faults contributed to the spaciotemporal variations in the subsidence within each basin.

Spatial and temporal changes in the assembly mechanism and co-occurrence network of the chromophytic phytoplankton communities in coastal ecosystems under anthropogenic influences

As a typical semiclosed coastal sea area in China, the ecological environment of Bohai Bay has been significantly disturbed by human activities. As primary producers, the chromophytic phytoplankton are the basis of ecosystems, especially in coastal ecosystems, and changes in the chromophytic phytoplankton community can affect the stability of the entire ecosystem. In this study, we investigated the effects of the human activity-induced spatial and temporal environmental heterogeneity on the community composition, diversity, assembly mechanisms, and co-occurrence networks of chromophytic phytoplankton in Bohai Bay during the wet season and the dry season. The results showed that in both seasons, there was obvious environmental heterogeneity between the nearshore area and the offshore area, and the nearshore areas were more affected by human disturbance. Although higher diversity was supported by the abundance of nutrients in nearshore areas, co-occurrence network analysis revealed that the chromophytic phytoplankton were less closely connected to each other in nearshore areas than in offshore areas due to chemical oxygen demand (COD), eutrophication index (EI), and dissolved inorganic nitrogen (DIN). The nearshore network was less stable than the offshore co-occurrence network in both seasons, which was related to the concentration of dissolved oxygen and COD. Both stochastic and deterministic processes dominated the assembly of the chromophytic phytoplankton communities, with different importance rankings of stochastic and deterministic processes in the nearshore and offshore areas. Drift dominated the assembly of the communities in nearshore areas, while variable selection dominated the assembly of the communities in offshore areas. DIN, EI, and COD, rather than geographic distance, were the main environmental factors affecting the phylogenetic turnover of the chromophytic phytoplankton. Our study showed that environmental heterogeneity caused by human disturbance had a greater impact on the chromophytic phytoplankton communities in Bohai Bay than natural factors such as temperature and salinity.

Genetic structure and local adaptation of Neptunea cumingii crosse populations in China based on GBS technology

To identify the genetic characteristics and local adaptation mechanism of the snail Neptunea cumingii in different sea areas of China, specimens from six coastal areas of the Yellow Sea and Bohai Sea were collected. Simplified genome technology was used to study the population genetic structure and genetic diversity level of N. cumingii and to infer the genetic variation pattern of environmental adaptation of this species. In total, 1992 discrete loci with high quality were obtained used for population genomics analysis. The observed heterozygosity was 0.1551–0.1612, and the expected heterozygosity was 0.1064–0.1117. Nucleotide diversity ranged from 0.1120 to 0.1241, and fixation index values ranged from −0.04683 to −0.02041. A total of 330 discrete loci were screened based on two fixation index values and a method associated with environmental factors. Functional annotation showed that the genes of discrete loci were involved in the three major functions of cell composition, biological process, and molecular function, including growth and development and cell metabolism and catalytic activity. These results suggested that different populations of N. cumingii had loci that may be related to local adaptation. The results of this study helped to clarify the level of genetic diversity and the germplasm genetic background of N. cumingii. They also provided information about the genetic mechanism of environmental adaptation of N. cumingii that can be applied to the restoration and management of N. cumingii resources.

Sublethal effects on the hard clam Mercenaria mercenaria after exposure to Aureococcus anophagefferens Chinese strain isolates

Brown tides caused by Aureococcus anophagefferens occur frequently worldwide and have contributed to the collapse of Mercenaria mercenaria farming in the United States. This economically valuable hard clam has been used in China for more than 20 years. To date, it has remained unknown whether A. anophagefferens Chinese strain has an impact on hard clam cultivation in the coastal areas of China or other sea areas worldwide if it enters through ship ballast water and other ways. In this study, a Chinese strain of A. anophagefferens isolated from the brown tide waters of Bohai Bay, China, was selected to explore its influence on the feedback of hard clams. After being fed with A. anophagefferens, hard clams showed characteristics similar to starvation. The reduced feeding efficiency of hard clams leads to reduced energy intake. However, the immune response and oxidative stress, result in increased energy consumption. An imbalance in the energy budget may be an important reason for hard clam starvation. This study has described the response characteristics of the A. anophagefferens Chinese strain to M. mercenaria, explored the reasons for the negative impact of A. anophagefferens on hard clams, and provides ideas for reducing shellfish aquaculture caused by brown tides.

Effects of habitat usage on hypoxia avoidance behavior and exposure in reef-dependent marine coastal species

Reef habitat in coastal ecosystems is increasingly being augmented with artificial reefs (ARs) and is simultaneously experiencing increasing hypoxia due to eutrophication and climate change. Relatively little is known about the effects of hypoxia on organisms that use complex habitat arrangements and how the presence of highly preferred AR habitat can affect the exposure of organisms to low dissolved oxygen (DO). We performed two laboratory experiments that used video recording of behavioral movement to explore 1) habitat usage and staying duration of individuals continuously exposed to 3, 5, and 7 mg/L dissolved oxygen (DO) in a complex of multiple preferred and avoided habitat types, and 2) the impact of ARs on exposure to different DO concentrations under a series of two-way replicated choice experiments with or without AR placement on the low-oxygen side. Six common reef-dependent species found in the northeastern sea areas of China were used (i.e., rockfish Sebastes schlegelii and Hexagrammos otakii, filefish Thamnaconus modestus, flatfish Pseudopleuronectes yokohamae, sea cucumber Stichopus japonicus, and crab Charybdis japonica). Results showed that lower DO levels decreased the usage of preferred habitats of the sea cucumber and the habitat-generalist filefish but increased the habitat affinity to preferred habitat types for the two habitat-specific rockfishes. Low DO had no effect on the crab’s habitat usage. In the choice experiment, all three fish species avoided 1 mg/L, and the rockfish S. schlegelii continued to avoid the lower DO when given choices involving pairs of 3, 5, and 7 mg/L, while H. otakii and the flatfish showed less avoidance. The availability of ARs affected exposure to low DO for the habitat-preferring rockfishes but was not significant for the flatfish. This study provides information for assessing the ecological effects and potential for adaptation through behavioral movement for key reef-dependent species under the increasing overlap of ARs and hypoxia anticipated in the future.

Influence of Ocean Tidal Loading on Continuous Gravity Observations in Eastern China

Global and regional ocean tide models are used to analyze the gravity effect of ocean tidal loading (OTL) for gravity stations in East China. The accuracies of OTL correction results for 21 gravity stations in East China are evaluated. The global ocean tide model is the most effective for the OTL correction of inland gravity stations (up to 90%) but is less effective for coastal gravity stations (only 60%). Considering regional ocean tide models, the applicability of OTL correction increased to 80% in coastal gravity stations. Based on the root sum square (RSS) method, among 16 combination models, the optimal combination model for OTL correction is the global model FES2014b by combing the regional model OSU.Chinasea.2010 (F14O). The RSS, which has reached 7.1 nms−2, is the minimum of the 16 combination models. Simulating with the F14O in the China Sea and adjacent areas, the gravity amplitude of the OTL is about 10 nms−2 in inland areas and > 50 nms−2 along the coastline. Especially in Southeastern China coastal areas and the southwestern coastal areas of the Korean Peninsula, the gravity amplitude of the OTL reaches about 80 nms−2. Moreover, the OTL changes drastically possibly owing to coastal topography. The results of this study provide a reference for selecting ocean tide models for high-precision analysis of continuous gravity observations in East China.

Future sea level rise dominates changes in worst case extreme sea levels along the global coastline by 2100

We provide the magnitude of a worst case scenario for extreme sea levels (ESLs) along the global coastline by 2100. This worst case scenario for ESLs is calculated as a combination of sea surface height associated with storm surge and wave (100 year return period, the 95th percentile), high tide (the 95th percentile) and a low probability sea level rise scenario (the 95th percentile). Under these conditions, end-of-21st century ESLs have a 5% chance of exceeding 4.2 m (global coastal average), compared to 2.6 m during the baseline period (1980–2014). By 2100 almost 45% of the global coastline would experience ESLs above the global mean of 4.2 m, with up to 9–10 m for the East China Sea, Japan and North European coastal areas. Up to 86% of coastal locations would face ESLs above 3 m (100 year return period) by 2100, compared to 33% currently. Up to 90% of increases in magnitude of ESLs are driven by future sea level rise, compare to 10% associated with changes in storm surges and waves. By 2030–2040 the present-day 100 year return period for ESLs would be experienced at least once a year in tropical areas. This 100-fold increase in frequency will take place on all global coastlines by 2100.

Spatial assessment of triazole organic compounds in surface water from the coastal estuaries to the East China sea

Triazole is widely used in the synthesis of pharmaceuticals, pesticides, and fungicides. However, triazole organic compounds are often a source of toxicity in the water environment due to the presence of chlorobenzene. This study reported on the occurrence and distribution of 15 TrOCs in the surface waters of estuaries and the East China sea, and identified the influences of TrOCs originating from the estuarine environment on the ocean. The results showed that the total concentrations of ∑TrOCs in the surface water of estuaries along the coasts of Jiangsu (JS), Zhejiang (ZJ), and Shanghai (SH), China ranged from 0.020 to 104 ng L−1 (7.49 ± 18.2 ng L−1), whereas they ranged from 0.235 to 1.25 ng L−1 (mean 0.711 ± 0.235 ng L−1) in the East China sea. Difenoconazole and tebuconazole were the dominant TrOCs in the estuaries, whereas fenbuconazole and hexaconazole dominated in the ocean. TrOCs in surface water of estuaries showed a continuous spatial distribution and presented regional characteristics mainly related to agricultural activities. In contrast, TrOCs in the East China Sea showed a low spatial variation and dispersion, which may be related to complex disturbance by currents and dilution. The low levels of estuarine TrOCs measured in SH estuaries (<0.5 ng L−1) indicates that the Yangtze River may only pose a low-level TrOC contamination risk to the East China Sea. Moreover, estuary transport in the estuaries of ZJ may have influenced the occurrence of TrOCs in the offshore East China Sea area, although they may have also undergone a filter process in the estuary turbid zone; whereas it had little influence on the open sea. This study can act as a critical reference for the presence of TrOCs in surface water both estuaries and the ocean.

Occurrence and distribution of lipophilic marine algal toxins in the coastal seawater of Southeast China and the South China Sea

The composition, levels, and spatial distribution of dissolved lipophilic marine algal toxins (LMATs) including cyclic imines (CIs), yessotoxins (YTXs), okadaic acid (OA) and its derivatives, pectenotoxins (PTXs), azaspiracids (AZAs), and brevetoxins (BTXs) in the coastal waters of Southeast China (Xiamen) and the South China Sea (Hainan Island and Beibu Gulf) were investigated and compared for the first time. Dissolved AZA3 was firstly detected in the coastal seawater of China. OA and PTX2 were widely distributed in the three areas studied. Gymnodimine (GYM), 13-desmethyl spirolide C (SPX1), YTX, and homo-yessotoxins (h-YTX) were found mainly in the South China Sea. The average ∑LMAT concentrations in the coastal waters of Xiamen, Hainan Island, and Beibu Gulf were 10.02 ng/L, 4.21 ng/L, and 44.27 ng/L, respectively. More groups and much higher concentrations of LMATs occurred in the South China Sea than that in the other sea areas of China.

Progress on the species diversity of polychaete annelids in the sea areas of China

Progress on the species diversity of polychaete annelids in the sea areas of China