Impact of summer hypoxia on macrobenthic communities in a semi-enclosed bay: A long-term observation in the North Yellow sea of China.

The O2 content of the global ocean has been declining progressively over the past decades, mainly because of human activities and global warming. Despite this situation, the responses of macrobenthos under hypoxic conditions remain poorly understood. In this study, we conducted a long-term observation (2015-2022) to investigate the intricate impact of summer hypoxia on macrobenthic communities in a semi-enclosed bay of the North Yellow Sea. Comparative analyses revealed higher macrobenthos abundance (1956.8 ± 1507.5 ind./m2 vs. 871.8 ± 636.9 ind./m2) and biomass (8.2 ± 4.1 g/m2 vs. 5.6 ± 3.2 g/m2) at hypoxic sites compared to normoxic sites during hypoxic years. Notably, polychaete species demonstrated remarkable adaptability, dominating hypoxic sites, and shaping community structure. The decline in biodiversity underscored the vulnerability and diminished resilience of macrobenthic communities to hypoxic stressors. Stable isotope analysis provided valuable insights into food web structures. The average trophic level of macrobenthos measured 2.84 ± 0.70 at hypoxic sites, contrasting with the higher value of 3.14 ± 0.74 observed at normoxic sites, indicating the absence of predators at high trophic levels under hypoxic conditions. Moreover, trophic interactions were significantly altered, resulting in a simplified and more vulnerable macrobenthic trophic structure. The findings underscored the importance of comprehensive research to understand the complex responses of macrobenthic communities to hypoxia, thereby informing future conservation efforts in impacted ecosystems.

Promoting effect of raft-raised scallop culture on the formation of coastal hypoxia.

The coastal waters around the Yangma Island are an important mariculture area of raft-raised scallop and bottom-seeded sea cucumber in the North Yellow Sea, China. Large-scale hypoxia in the bottom water of this area has caused the death of a large number of sea cucumbers and heavy economic losses. To find out the formation mechanism of hypoxia, the data obtained in each August during 2015-2018 were analyzed. Compared with the non-hypoxic year (2018), the temperature, trophic index (TRIX) and dissolved organic carbon (DOC) in the bottom water were relatively higher, and the water column was stratified causing by continuous high air temperature and low wind speed meteorological conditions in the hypoxic years (2015-2017). These sites with the coexistence of thermocline and halocline, and the thickness of thermocline >2.5 m and its upper boundary >7.0 m deep, were prone to hypoxia. Spatially, the hypoxic place was highly consistent with the scallop cultivating places, and the DOC, TRIX, NH4+/NO3- and apparent oxygen utilization (AOU) at the culture sites were higher, indicating that organic matter and nutrients released by scallops may lead to local oxygen depletion. In addition, the bottom water of the culture sites had higher salinity, but lower turbidity and temperature, indicating that the slowed water exchange caused by scallop culture was a dynamic factor of hypoxia. All sites with AOU >4 mg/L at the bottom had hypoxia occurrence, even if there was no thermocline. In other words, stratification promoted the formation of hypoxia in coastal bottom water, but it was not indispensable. The raft-raised scallop culture could promote the formation of coastal hypoxia, which should arouse the attention for other coastal areas with intensive bivalve production.

A Multi-Scale Anti-Multipath Algorithm for GNSS-RTK Monitoring Application.

During short baseline measurements in the Real-Time Kinematic Global Navigation Satellite System (GNSS-RTK), multipath error has a significant impact on the quality of observed data. Aiming at the characteristics of multipath error in GNSS-RTK measurements, a novel method that combines improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) and adaptive wavelet packet threshold denoising (AWPTD) is proposed to reduce the effects of multipath error in GNSS-RTK measurements through modal function decomposition, effective coefficient sieving, and adaptive thresholding denoising. It first utilizes the ICEEMDAN algorithm to decompose the observed data into a series of intrinsic mode functions (IMFs). Then, a novel IMF selection method is designed based on information entropy to accurately locate the IMFs containing multipath error information. Finally, an optimized adaptive denoising method is applied to the selected IMFs to preserve the original signal characteristics to the maximum possible extent and improve the accuracy of the multipath error correction model. This study shows that the ICEEMDAN-AWPTD algorithm provides a multipath error correction model with higher accuracy compared to singular filtering algorithms based on the results of simulation data and GNSS-RTK data. After the multipath correction, the accuracy of the E, N, and U coordinates increased by 49.2%, 65.1%, and 56.6%, respectively.

Learning Background-Suppressed Dual-Regression Correlation Filters for Visual Tracking.

The discriminative correlation filter (DCF)-based tracking method has shown good accuracy and efficiency in visual tracking. However, the periodic assumption of sample space causes unwanted boundary effects, restricting the tracker's ability to distinguish between the target and background. Additionally, in the real tracking environment, interference factors such as occlusion, background clutter, and illumination changes cause response aberration and, thus, tracking failure. To address these issues, this work proposed a novel tracking method named the background-suppressed dual-regression correlation filter (BSDCF) for visual tracking. First, we utilize the background-suppressed function to crop out the target features from the global features. In the training step, while introducing the spatial regularity constraint and background response suppression regularization, we construct a dual regression structure to train the target and global filters separately. The aim is to exploit the difference between the output response maps for mutual constraint to highlight the target and suppress the background interference. Furthermore, in the detection step, the global response can be enhanced by a weighted fusion of the target response to further improve the tracking performance in complex scenes. Finally, extensive experiments are conducted on three public benchmarks (including OTB100, TC128, and UAVDT), and the experimental results indicate that the proposed BSDCF tracker achieves tracking performance comparable to many state-of-the-art (SOTA) trackers in a variety of complex situations.

Lightweight 3D Dense Autoencoder Network for Hyperspectral Remote Sensing Image Classification.

The lack of labeled training samples restricts the improvement of Hyperspectral Remote Sensing Image (HRSI) classification accuracy based on deep learning methods. In order to improve the HRSI classification accuracy when there are few training samples, a Lightweight 3D Dense Autoencoder Network (L3DDAN) is proposed. Structurally, the L3DDAN is designed as a stacked autoencoder which consists of an encoder and a decoder. The encoder is a hybrid combination of 3D convolutional operations and 3D dense block for extracting deep features from raw data. The decoder composed of 3D deconvolution operations is designed to reconstruct data. The L3DDAN is trained by unsupervised learning without labeled samples and supervised learning with a small number of labeled samples, successively. The network composed of the fine-tuned encoder and trained classifier is used for classification tasks. The extensive comparative experiments on three benchmark HRSI datasets demonstrate that the proposed framework with fewer trainable parameters can maintain superior performance to the other eight state-of-the-art algorithms when there are only a few training samples. The proposed L3DDAN can be applied to HRSI classification tasks, such as vegetation classification. Future work mainly focuses on training time reduction and applications on more real-world datasets.

A Simple and Effective Visual Fluorescent Sensing Paper-Based Chip for the Ultrasensitive Detection of Mercury Ions in Environmental Water.

Traces of mercury ions in environmental water can harm humans and animals. Paper-based visual detection methods have been widely developed for the rapid detection of mercury ions; however, existing methods are not sensitive enough to be used in real environments. Here, we developed a novel, simple and effective visual fluorescent sensing paper-based chip for the ultrasensitive detection of mercury ions in environmental water. CdTe-quantum-dots-modified silica nanospheres were firmly absorbed by and anchored to the fiber interspaces on the paper's surface to effectively avoid the unevenness caused by liquid evaporation. The fluorescence of quantum dots emitted at 525 nm can be selectively and efficiently quenched with mercury ions, and the ultrasensitive visual fluorescence sensing results attained using this principle can be captured using a smartphone camera. This method has a detection limit of 2.83 µg/L and a fast response time (90 s). We successfully achieved the trace spiking detection of seawater (from three regions), lake water, river water and tap water with recoveries in the range of 96.8-105.4% using this method. This method is effective, low-cost, user-friendly and has good prospects for commercial application. Additionally, the work is expected to be utilized in the automated big data collection of large numbers of environmental samples.

Characterization of the metabolites of tirabrutinib generated from rat, dog and human liver microsomes using ultra-high-performance liquid chromatography combined with high-resolution mass spectrometry.

RATIONALE: Tirabrutinib is an orally administered Bruton's tyrosine kinase (BTK) inhibitor developed for the treatment of autoimmune disorders and haematological malignancies. The goals of this study were to identify the metabolites of tirabrutinib and to propose the metabolic pathways. METHODS: Tirabrutinib was individually incubated with rat, dog and human liver microsomes at 37°C for 1 h. To trap the potential reactive metabolites, glutathione (GSH) was incorporated into the incubation samples. The incubation samples were analysed using ultra-high-performance liquid chromatography combined with high-resolution mass spectrometry (UHPLC-HRMS). The metabolites were identified and characterized by exact masses, product ions and retention times. RESULTS: A total of 18 metabolites, including four GSH conjugates, were identified and characterized in terms of elemental compositions and product ions. The metabolic pathways of tirabrutinib included amide hydrolysis, O-dealkylation, mono-oxygenation, di-oxygenation and GSH conjugation. Among these metabolites, M10 was the most abundant metabolite. Compared with dog, rat has the closer metabolic profiles to humans, and thus it would be more suitable for toxicity study. CONCLUSIONS: This study provides valuable data regarding the in vitro metabolism of tirabrutinib, which may be helpful for further safety assessment of this drug.

A Partial Ambiguity Resolution Algorithm Based on New-Breadth-First Lattice Search in High-Dimension Situations.

With the development and integration of GNSS systems in the world, the positioning accuracy and reliability of GNSS navigation services are increasing in various fields. Because the current multisystem fusion leads to an increase in the ambiguity dimension and the ambiguity parameters have discrete characteristics, the current conventional search algorithm leads to low search efficiency when the ambiguity dimension is large. Therefore, this paper describes a new algorithm that searches the optimal lattice points by lattice theory through the breadth-first algorithm and reduces the search space of ambiguity by calculating and judging the Euclidean distance between each search variable and the target one so as to propose a new lattice ambiguity search algorithm based on the breadth-first algorithm. The experimental results show that this method can effectively improve the search efficiency of ambiguity in high-dimension situations.

A Partial Carrier Phase Integer Ambiguity Fixing Algorithm for Combinatorial Optimization between Network RTK Reference Stations.

In the face of a complex observation environment, the solution of the reference station of the ambiguity of network real-time kinematic (RTK) will be affected. The joint solution of multiple systems makes the ambiguity dimension increase steeply, which makes it difficult to estimate all the ambiguity. In addition, when receiving satellite observation signals in the environment with many occlusions, the received satellite observation values are prone to gross errors, resulting in obvious deviations in the solution. In this paper, a new network RTK fixation algorithm for partial ambiguity among the reference stations is proposed. It first estimates the floating-point ambiguity using the robust extended Kalman filtering (EKF) technique based on mean estimation, then finds the optimal ambiguity subset by the optimized partial ambiguity solving method. Finally, fixing the floating-point solution by the least-squares ambiguity decorrelation adjustment (LAMBDA) algorithm and the joint test of ratio (R-ratio) and bootstrapping success rate index solver. The experimental results indicate that the new method can significantly improve the fixation rate of ambiguity among network RTK reference stations and thus effectively improve the reliability of positioning results.

An Unambiguous Synchronization Scheme for GNSS BOC Signals Based on Reconstructed Correlation Function.

Binary offset carrier (BOC) modulation is a new modulation method that has been gradually applied to the Global Satellite Navigation System (GNSS) in recent years. However, due to the multi-peaks in its auto-correlation function (ACF), it will incur a false lock and generate synchronization ambiguous potentially. In this paper, an unambiguous synchronization method based on a reconstructed correlation function is proposed to solve the ambiguity problem. First, through the shape code vector constructed in this paper, the general cross-correlation function (CCF) expression of the BOC modulated signal will be obtained. Based on the features of the signal correlation function, it is decomposed into a matrix form of trigonometric functions. Then, it generates two local signal waves using a specific method, then the proposed method is implemented to obtain a no-side-peak correlation function by reconstructing the cross-correlation between the received signal and the two local signals. Simulations showed that it fully eliminates the side-peak threat and significantly removes the ambiguity during the synchronization of the BOC signals. This paper also gives the improved structure of acquisition and tracking. The detailed theoretical deduction of detection probability and code tracking error is demonstrated, and the corresponding phase discrimination function is given. In terms of de-blurring ability and detection probability performance, the proposed method outperformed other conventional approaches. The tracking performance was superior to the comparison methods and the phase discrimination curve only had a zero-crossing, which successfully removed the false lock points. In addition, in multipath mitigation, it outperformed the ACF of the BOC signal, and performs as well as the autocorrelation side-peak cancellation technique (ASPeCT) for BOC(kn,n) signals.

Individual and Combined Toxicities of Benzo[a]pyrene and 2,2',4,4'-Tetrabromodiphenyl Ether on Early Life Stages of the Pacific Oyster, Crassostrea gigas.

Persistent organic pollutants (POPs) are ubiquitous and coexisted in the aquatic environment. Individual and combined toxic effects of benzo[a]pyrene (BaP) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) on embryogenesis, and larval survival of the Pacific oyster were investigated. The EC50 values of BaP, BDE-47 and their mixture on embryogenesis were 18.4, 203.3 and 72.0 µg/L respectively, while the LC50 values for 96 h larval mortality were 26.8, 244.5 and 108.9 µg/L respectively. The Marking-Dawson additive toxicity indices were -0.02 and -0.19, indicating an additive effect with a trend to antagonism. In addition, DNA strand breaks were also observed in oyster embryos after exposure. Our study suggests that BaP and BDE-47 exposure can cause developmental abnormalities, DNA damage and larval mortality. Furthermore, the toxicity of the mixture is slightly lower than individual pollutant. These data will be helpful to predict the toxicity of organic pollutants, and provide criteria for marine water quality standards.

Metabolomics revealed more deleterious toxicity induced by the combined exposure of ammonia and nitrite on Ruditapes philippinarum compared to single exposure.

NH3-N and NO2-N always co-exist in the aquatic environment, but there is not a clear opinion on their joint toxicities to the molluscs. Presently, clams Ruditapes philippinarum were challenged by environmental concentrations of NH3-N and NO2-N, singly or in combination, and analyzed by metabolomics approaches, enzyme assays and transmission electron microscope (TEM) observation. Results showed that some same KEGG pathways with different enriched-metabolites were detected in the three exposed groups within one day, and completely different profiles of metabolites were found in the rest of the exposure period. The combined exposure induced heavier and more lasting toxicities to the clams compared with their single exposure. ACP activity and the number of secondary lysosomes were significantly increased after the combined exposure. The present study shed light on the joint-toxicity mechanism of NH3-N and NO2-N, and provided fundamental data for the toxicity research on inorganic nitrogen.

Biodiversity and distribution patterns of blooming jellyfish in the Bohai Sea revealed by eDNA metabarcoding.

BACKGROUND: The mass occurrence of scyphozoan jellyfish severely affects marine ecosystems and coastal economies, and the study of blooming jellyfish population dynamics has emerged in response. However, traditional ecological survey methods required for such research have difficulties in detecting cryptic life stages and surveying population dynamics owing to high spatiotemporal variations in their occurrence. The environmental DNA (eDNA) technique is an effective tool for overcoming these limitations. RESULTS: In this study, we investigated the biodiversity and spatial distribution characteristics of blooming jellyfish in the Bohai Sea of China using an eDNA metabarcoding approach, which covered the surface, middle, and bottom seawater layers, and sediments. Six jellyfish taxa were identified, of which Aurelia coerulea, Nemopilema nomurai, and Cyanea nozakii were the most dominant. These three blooming jellyfish presented a marked vertical distribution pattern in the offshore regions. A. coerulea was mainly distributed in the surface layer, whereas C. nozakii and N. nomurai showed a upper-middle and middle-bottom aggregation, respectively. Horizontally, A. coerulea and C. nozakii were more abundant in the inshore regions, whereas N. nomurai was mainly distributed offshore. Spearman's correlation analysis revealed a strong correlation between the eDNA of the three dominant blooming jellyfish species and temperature, salinity, and nutrients. CONCLUSIONS: Our study confirms the applicability of the eDNA approach to both biodiverstiy evaluation of blooming jellyfish and investigating their spatial distribution, and it can be used as a supplementary tool to traditional survey methods.

Stimulation of TLR4 by LMW-HA induces metastasis in human papillary thyroid carcinoma through CXCR7.

In inflammatory sites, high molecular weight hyaluronan fragments are degraded into lower molecular weight hyaluronan fragments (LMW-HA) to regulate immune responses. However, the function of LMW-HA in PTC progression remains to be elucidated. In this study, we found that receptor of LMW-HA, TLR4, was aberrantly overexpressed in PTC tissues and cell line W3. Exposure of W3 cells to LMW-HA promoted cell proliferation and migration via TLR4. Knockdown of TLR4 has provided evidence that TLR4 is essential for LMW-HA-induced CXCR7 expression, which is responsible for LMW-HA-induced proliferation and migration of W3 cells. In tumor-bearing adult nude mice, stimulation of LMW-HA on W3 cells promotes CXCR7 expression in tumor masses (P = 0.002) and tumor growth (P < 0.001). To further confirm our findings, we investigated the clinicopathologic significance of TLR4 and CXCR7 expression using immumohistochemistry in 135 human PTC tissues and 56 normal thyroid tissue samples. Higher rates of TLR4 (53%) and CXCR7 (24%) expression were found in PTC tissues than in normal tissues. Expression of TLR4 or CXCR7 is associated with tumor size and lymph node metastasis. Therefore, LMW-HA may contribute to the development of PTC via TLR4/CXCR7 pathway, which may be a novel target for PTC immunomodulatory therapy.

[Retracted] miR­30a­5p inhibits the proliferation, migration and invasion of melanoma cells by targeting SOX4.

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that the tumour images shown in Fig. 3B were strikingly similar to data appearing in different form in another article written by different authors at different research institutes. Owing to the fact that the contentious data in the above article were already under consideration for publication prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 18: 2492­2498, 2018; DOI: 10.3892/mmr.2018.9166].

Selective cationic covalent organic framework for high throughput rapid extraction of novel polyfluoroalkyl substances.

Novel per- and polyfluoroalkyl substances (PFASs) raise global concerns due to their toxic effects on environment and human health. However, researches on analytical methods of novel PFASs are lacking. Here, a kind of selective cationic covalent organic framework (iCOF) was designed and loaded on the surface of cotton as an adsorbent. Then, a simple solid-phase extraction (SPE) method based on the cotton@iCOF was developed for high throughput rapid extraction of six novel PFASs in water samples, coupled with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) determination. Several important SPE parameters, such as the amount of iCOF, sample pH, desorption conditions and salinity were systematically investigated. Under optimal conditions, the limits of detection and quantification of this SPE-UHPLC-MS/MS method were as low as 0.08-2.14 ng/L and 0.28-7.15 ng/L, respectively. The recoveries were 77.9-117.6 % for the tap water and surface water, and F-53 B in surface water were detected. Notably, this SPE process was rapid (1 h for 500 mL water sample) compared with commercial SPE (normal 2-3 h), owing to little resistance of cotton@iCOF and omission of nitrogen blowing process, and high throughput with 12 samples concurrently extracted. Additionally, various characterization means and density functional theory (DFT) calculations showed that ion-exchange effect, hydrophobic interaction, hydrogen bonding and ordered channel structure synergistically contributed to the PFASs adsorption on cotton@iCOF. The cotton@iCOF-based SPE method with simplicity, rapidity, selectivity and efficiency provided new research ideas for the analysis and control of ionic emerging pollutants in water.

Dissolved oxygen gradient on three dimensionally printed microfluidic platform for studying its effect on fish at three levels: cell, embryo, and larva.

A simple and low-cost dissolved oxygen gradient platform of three dimensionally (3D) printed microfluidic chip was developed for cultivating cells, embryos, and larvae of fish. "Christmas tree" structure channel networks generated a dissolved oxygen gradient out of two fluids fed to the device. Polydimethylsiloxane (PDMS) membrane with high biocompatibility was used as the substrate for cell culture in the 3D-printed microfluidic chip, which made the cell analysis easy. The embryos and larvae of fish could be cultured directly in the chip, and their development can be observed in real time with a microscope. Using zebrafish as a model, we assessed the effect of different dissolved oxygen on its cells, embryos, and larvae. Hypoxia induced production of reactive oxygen species (ROS) in zebrafish cells, embryos, and larvae, eventually leading to cell apoptosis and developmental impairment. Hypoxia also increased nitric oxide content in zebrafish cells, which might be a defensive strategy to overcome the adverse effect of hypoxia in fish cells. This is the first platform that could comprehensively investigate the effects of different dissolved oxygen on fish at the cell, embryo, and larva levels, which has great potential in studying the responses of aquatic organisms under different oxygen concentrations.

Nitrogen-doped metal-organic framework derived porous carbon/polymer membrane for the simultaneous extraction of four benzotriazole ultraviolet stabilizers in environmental water.

Benzotriazole ultraviolet stabilizers (BUVSs) that are added to pharmaceutical and personal care products (PPCPs) have raised global concerns because of their high toxicity. An efficient method to monitor its pollution level is urgently imperative. Here, a nitrogen-doped metal-organic framework (MOF) derived porous carbon (UiO-66-NH2/DC) was prepared and integrated into polyvinylidene fluoride mixed matrix membrane (PVDF MMM) as an adsorbent for the first time. The hydrophobic UiO-66-NH2/DC with a pore size of 162 Å exhibited outstanding extraction performance for BUVSs, which solves the problem of difficult enrichment of large-size and hydrophobic targets. Notably, the density functional theory simulation was employed to reveal the structure of the derived carbon material and explored the recognition and enrichment mechanism (synergy of π-π conjugation, hydrogen bond, coordination, hydrophobic interaction and mesoporous channel) of BUVSs by UiO-66-NH2/DC-PVDF MMM. And then, an influential method based on dispersive membrane extraction (DME) coupled with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for the simultaneous analysis of four BUVSs in environmental water samples. The validated method benefited from the high sensitivity (the limits of detection within 0.25-1.40 ng/L), accuracy (recoveries of 71.9-102.8% for wastewater) and rapidity (50 min to enrich 9 samples). This study expands the application prospects of porous carbon derived from MOF for sample pretreatment of pollutants in water.

Differences in seed characteristics, germination and seedling growth of Suaeda salsa grown in intertidal zone and on saline inland.

The ecological restoration of saline land in the Yellow River Delta is essential for the sustainability of this region. Halophytic species, like Suaeda salsa, are critical for the restoration process. However, potential differences in traits of heteromorphic seeds collected from the intertidal zone and inland condition have been largely overlooked. The seeds were analyzed for hardness, nutrient elements, and secretions, while structural differences were observed under a stereomicroscope. Germination percentages of the different seed types and subsequent seedling growth were also recorded. Our study found that the black seeds from intertidal zone had the highest hardness when compared to the three other types of seeds. Nutrient analysis revealed that brown seeds had a higher iron (Fe) content than black seeds. Accordingly, brown seed embryos were greener compared to their black seed counterparts due to the iron's role in chlorophyll synthesis. Our results also revealed that brown seeds secreted greater amounts of exudates than black seeds. Finally, both the intertidal brown seeds and the inland-grown brown seeds had higher germination percentages and better early seedling growth than the corresponding black seeds. The differential characteristics between dimorphic seeds and seedlings may influence their environmental adaptation in different saline environments.

Effects of instantaneous changes in temperature, light, and salinity on the dynamics of dissolved organic carbon release by Sargassum thunbergii.

Although macroalgae are regarded as the emerging fourth category of "blue carbon", few studies are available on the dynamics of dissolved organic carbon (DOC) release. Sargassum thunbergii is a typical intertidal macroalgae; and tidal action usually triggers instantaneous changes in temperature, light and salinity. Therefore, we investigated the mechanism of short-term changes in temperature, light and salinity on DOC release by S. thunbergii. As well as these factors coupled with desiccation, the combined effect of DOC release was revealed. The results showed the DOC release rate of S. thunbergii was from 0.028 to 0.037 mg C g -1(FW) h-1 under different photosynthetically active radiation (PAR, 0-1500 µmol photons m-2 s-1). The DOC release rate of S. thunbergii was from 0.008 to 0.208 mg C g -1(FW) h-1 under different salinity (5-40). The DOC release rate of S. thunbergii was from 0.031 to 0.034 mg C g -1(FW) h-1 under different temperature (10-30 °C). Either the increase in intracellular organic matter concentration due to increased photosynthesis (change in PAR and temperature, active), cell dehydration due to dry-out process (passive) or the decrease in extracellular salt concentration (passive) would lead to an increase in the difference in osmotic pressure and promote DOC release.