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Noble and commoner in the medieval China capital of Chang'an (modern-day Xi'an) engaged in an intricately intertwined agricultural and pastoral economy. The period represents the peak of the integration of nomadic and agricultural populations in early China. Here we firstly reported human collagen δ13C and δ15N values for eight middle age nobles whose lifespans cover roughly a century (AD 503–604) and who include a Northern Zhou, Emperor Wu (北周武帝) and his consort, Empress A'shina (阿史那皇后). We also consider stable isotopic evidence from nine individuals in commoner burials in the Chang'an region, likewise dating to the sixth century. This century-long dietary profile provides direct archeological evidence for dietary variability at this core metropolitan population. Constructing a comparative model using existing historical human isotopic data (n = 1233) from northern China and its northern Steppe, we find a marked regional divergence in noble and commoner dietary patterns. We trace this back to the considerable variety of agricultural and pastoral dietary practices, likely pointing to different economic and geographic backgrounds of the individuals under study. We argue that a two-way relationship between shifting pastoral and agricultural practices was reflected to separate degrees at the elite and commoner level. This study offers an improved understanding of the multiplicity of dietary patterns and associated lifeways for the metropolitan societies of medieval northern China. [ABSTRACT FROM AUTHOR]

Sponge city is a method of managing rain floods, proposed by China to deal with urban waterlogging and the overflow pollution of drainage pipe networks, which indicates a more effective strategy to promote urban sustainable development. Due to the diversity of sponge city construction objectives and the complexity of the developmental system, a unified and effective sustainability evaluation method has not yet been formed. Based on the emergy analysis method, the indicators of ecosystem service, the construction cost, the runoff regulation, and the pollutant reduction of sponge city construction are thus included in the evaluation system, and the sustainable evaluation model of a sponge city is fully constructed. Taking the core area in the south of Haicang in Xiamen City as the studying object, the runoff regulation, and the pollutant reduction indicators, are carefully obtained by using Info Works simulation software. The results showed that: ① the quality of COD (Chemical Oxygen Demand) of pollutants discharged from the research object is 409.8t/a, the total runoff is 3.579 million m3/a, the current annual total runoff control rate is 37.15%, and the current emergy index ESI of sponge city system is 0.05 < 1, which is in an unsustainable state, It is necessary to upgrade and transform the urban underlying surface; ② The transformation intensity of three LID (Low Impact Development) facilities, i.e., concave green space, permeable pavement and green roof, is carefully selected as different construction schemes. When the construction intensity of LID is 25%, the emergy index ESI (Emergy Sustainable Index) = 1.08, which meets the basic requirements of sustainable development; As long as the reconstruction construction intensity is 30%, the growth value of ESI, ΔESI, is the largest, the sustainable growth effect of sponge city construction is the most obvious, and the marginal benefit is the largest; ③ As long as the total annual runoff control rate of the research object is 69–82%, its sustainable energy index ESI should be within the range of 1.39–1.83. If ESI is less than 1.39, this indicates that the total annual runoff control rate of the research area cannot adapt to the planning requirements of 69%. [ABSTRACT FROM AUTHOR]

Previous studies on the impact of the mining of metal-bearing minerals on surrounding soil mainly focused on single or a few areas. However, these studies' results cannot provide effective making-support for soil pollution control in large-scale areas, especially in cross-provincial scale. This study first collected 78 literature before 2020 on soil heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) affected by the mining of metal-bearing minerals in Southwest China. Then, the geo-accumulation index, ecological risk, and health risk were assessed based on the extracted heavy metal data. Results showed that As, Cd, Hg, and Pb should be selected as the preferentially controlled heavy metals; Yunnan and Guizhou Provinces should be selected as the preferentially concerned areas; children should be given priority attention. The results provided more effective decision support for reducing heavy metal pollution in the areas affected by the mining of metal-bearing minerals in Southwest China. [ABSTRACT FROM AUTHOR]

Abstract: A month-long investigation of phytoplankton biomass and primary production (PP) was carried out during a harmful algal bloom (HAB) in Daya Bay, China, in 2003. During the bloom, the phytoplankton community was dominated by Scrippsiella trochoidea and Chattonella marina. The phytoplankton biomass (Chl a) and PP reached peak levels of 519.21mgm−3 and 734.0mgCm−3 h−1, respectively. Micro-phytoplankton was the key contributor to Chl a and PP in a cage-culture area and in the adjacent HAB-affected waters, with percentages of up to 82.91% and 84.94%, respectively. The HAB had complicated relationships with hydrological and meteorological factors in Daya Bay. However, the water around the cage-culture area always showed statistically greater phytoplankton biomass and nutrient loadings than in adjacent waters, suggesting that this was the “trigger area” of the bloom. The spatial and temporal distribution of diverse HABs in Daya Bay, their ecological characteristics, and their environmental impacts are also discussed in this paper. [Copyright &y& Elsevier]

Examines the spectral absorption coefficients of the total particulate, nonalgal particulate and phytoplankton pigments in the Pearl River estuary in China and its vicinity waters using the quantitative filter technique. Range of particulate absorption; Typical spectral patterns found for the total particulate absorption; Increase in the chlorophyll-specific absorption coefficients of phytoplankton pigment with decreasing chlorophyll level.

• Soil type affects the concentrations of TN and TP in surface and bottom soil. • Soil type was used as auxiliary data in the source apportionment of soil TN and TP. • RRK obtained higher spatial prediction accuracy than RK and OK. • The exogenous net inputs of soil TN and TP were determined in a large-scale area. • RRK and soil type effectively apportioned the sources of TN and TP in topsoil. Previous studies on the source apportionment of soil total nitrogen (TN) and total phosphorus (TP) mainly focused on specific spatial point sites and the closely related information such as soil-type map was seldom used. Moreover, traditional geostatistical models are usually sensitive to outliers. To address these problems, this study first proposed robust residual kriging (RRK) with soil-type data as auxiliary information to increase the spatial prediction accuracies for TN and TP in topsoil (0–20 cm) in Jintan County, China. Then, the spatial distribution patterns of the background concentrations of soil TN and TP were quantitatively assessed based on profile samples (80–100 cm) and the soil-type map. Last, the spatial distribution patterns of exogenous net inputs of TN and TP in topsoil and the corresponding contribution ratios were further calculated. Model comparisons showed that the relative improvement (RI) accuracies of RRK and residual kriging (RK) over the traditionally-used ordinary kriging (OK) were 23.91% and 15.22% for soil TN and 24.14% and 20.69% for soil TP, respectively. The results of the source apportionment indicated that (i) the exogenous net inputs of TN and TP had similar spatial distribution patterns, with the low inputs mainly in the west and high inputs mainly in the northeast and east of the county; (ii) high contribution ratio of exogenous net input of TN (≥67%) in topsoil was mainly located in the north, southeast, and middle of the study area, and the area with the contribution ratio over 70% is 294.16 km2, covering 30.16% of the area of the county; (iii) high contribution ratio of exogenous net input of TP (≥53%) in topsoil was mainly located in the north, northeast, and southeast of the county, and the area with contribution ratio over 70% is 24.35 km2, covering 2.50% of the area of the county. These results provided more accurate spatial decision support for effectively regulating TN and TP in topsoil. [ABSTRACT FROM AUTHOR]

Background: Metabolic syndrome (MetS) includes obesity, diabetes, dyslipidemia and hypertension. Its incidence is rapidly increasing worldwide, particularly in postmenopausal women. Estrogens regulate glucose homeostasis and lipid metabolism via estrogen receptors 1 (ESR1) and 2 (ESR2). The current study aimed to elucidate associations of MetS with ESR1 and ESR2 gene polymorphisms in postmenopausal Chinese women. Methods: This case-control study included 304 postmenopausal women (154 and 150 control and MetS patients, respectively). Clinical indicators related to MetS were assessed. Two ESR1 (PvuII and XbaI) and two ESR2 (RsaI and AluI) polymorphisms were evaluated by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis. Results: ESR1 polymorphisms were significantly different between MetS patients and healthy controls. G allele frequency for the XbaI polymorphism was significantly higher in patients than in control patients (p = 0.004, OR = 1.610, 95%CI 1.169–2.18). The haplotypes A–T (p = 0.015) and G–C (p = 0.024) showed significant differences. The minor alleles of the XbaI and PvuII gene polymorphisms in both homozygous and heterozygous forms showed associations with elevated waist circumference, fasting serum insulin and HOMA-IR. The minor G allele in homozygous and heterozygous forms of the RsaI and AluI gene polymorphisms showed associations with elevated total cholesterol and LDL-C. Conclusions: In postmenopausal Chinese women, ESR1 polymorphism and the haplotypes A–T and G–C of XbaI–PvuII are associated with MetS, unlike ESR2 polymorphisms. Patients harboring the G allele of XbaI have elevated BMI, waist circumference, systolic and diastolic BP, FBG, HOMA-IR, total cholesterol, TG, LDL-C and NAFLD (%), and reduced HDL-C. [ABSTRACT FROM AUTHOR]

Abstract: The dynamics of size-fractionated phytoplankton along the salinity gradient in the Pearl River Estuary and the adjacent near-shore oceanic water was investigated using microscopic, flow cytometric, and chlorophyll analyses in the early spring (March) and early autumn (September) of 2005. In the inner part of the estuary where salinity was less than 30, the phytoplankton community was dominated by micro- and nano-sized (3–200μm) cells, particularly the diatom Skeletonema costatum, both in early spring and early autumn. In areas where salinity >30, including the mixing zone and nearshore oceanic water, micro- and nano-sized cell populations dominated the phytoplankton assemblage during early spring when influence of river discharge was minimal, whereas pico-sized (≤3μm) cell populations were dominant during early autumn as a result of strong river discharge in the summer, with Synechococcus and pico-eukaryotes being predominant. Picophytoplankton were two orders of magnitude more abundant in early autumn (106 cellsmL−1) than in early spring in the nearshore oceanic water. Nutrients delivered by freshwater input to the estuary were pushed toward high salinity (>30) areas as a result of short residence time, exerting a strong influence on phytoplankton abundance, especially picophytoplankton in the nearshore, otherwise oligotrophic, water. Influenced by high abundance of DIN and limitation in phosphorus, picophytoplankton in the adjacent nearshore oceanic water rose to prominence seasonally. Our results indicate that eutrophication in the Pearl River Estuary not only stimulates the growth of S. costatum in the nutrient-rich areas of the estuary but also appears to promote the growth of Synechococcus and pico-eukaryotes in the adjacent usually oligotrophic oceanic water at least during our autumn cruise. [Copyright &y& Elsevier]

• A novel assessment method for SFQI was proposed based on GWPCA (i.e., SFQI GWPCA). • Spatially varying relationships among soil indicators were revealed by GWPCA. • Spatially varying indicator weights were determined by GWPCA rather than PCA. • SFQI GWPCA is an effective method for SFQI assessment in large-scale areas. • The spatial uncertainty of SFQI GWPCA was revealled by the simulated realizations. Principal component analysis (PCA) has been widely used in the integrated soil fertility quality index (SFQI) (SFQI PCA) assessment. However, the traditional PCA, only established in variable space, does not consider the spatially varying relationships among soil fertility indicators in large-scale areas, and thus cannot appropriately determine the spatially varying relative importance (i.e., weight calculated based on communality) of soil indicators in the SFQI assessment. Moreover, uncertainty inevitably exists in the spatial distribution pattern of SFQI due to the limited sample points, which is critical to the precision management of soil fertility. To address these limitations, this study first proposed a novel assessment method for SFQI based on geographically weighted principal component analysis (GWPCA) (SFQI GWPCA). Secondly, SFQI GWPCA was assessed in Shayang County, China, and then compared with the traditional SFQI PCA. Finally, the spatial uncertainty of SFQI GWPCA was assessed based on the 1000 realizations generated by sequential Gaussian simulation (SGS). Results showed that (i) spatially varying relationships among soil indicators were revealed by Monte Carlo test and GWPCA outputs (i.e., the winning variable and the local percentage of total variation), while traditionally-used PCA was conducted in the assumption of spatially stationary relationships among soil indicators; (ii) in SFQI assessment, the spatially varying indicator weights were determined by GWPCA, but could not be determined by PCA; (iii) the areas with higher threshold-exceeding probability (≥ 0.95) mainly located in the northwest of this county, and the areas with lower threshold-exceeding probability (≤ 0.05) mainly located in the east of this county. It is concluded that GWPCA adequately considers the spatially varying relationships among soil indicators, and SFQI GWPCA is an effective tool in the SFQI assessment in large-scale areas. [ABSTRACT FROM AUTHOR]

Emperor Wu (, Wudi) of the Xianbei-led Northern Zhou dynasty, named Yuwen Yong (, 543-578 CE), was a highly influential emperor who reformed the system of regional troops, pacified the Turks, and unified the northern part of the country. His genetic profile and physical characteristics, including his appearance and potential diseases, have garnered significant interest from the academic community and the public. In this study, we have successfully generated a 0.343×-coverage genome of Wudi with 1,011,419 single-nucleotide polymorphisms (SNPs) on the 1240k panel. By analyzing pigmentation-relevant SNPs and conducting cranial CT-based facial reconstruction, we have determined that Wudi possessed a typical East or Northeast Asian appearance. Furthermore, pathogenic SNPs suggest Wudi faced an increased susceptibility to certain diseases, such as stroke. Wudi shared the closest genetic relationship with ancient Khitan and Heishui Mohe samples and modern Daur and Mongolian populations but also showed additional affinity with Yellow River (YR) farmers. We estimated that Wudi derived 61% of his ancestry from ancient Northeast Asians (ANAs) and nearly one-third from YR farmer-related groups. This can likely be attributed to continuous intermarriage between Xianbei royal families, and local Han aristocrats. 1 , 2 Furthermore, our study has revealed genetic diversities among available ancient Xianbei individuals from different regions, suggesting that the formation of the Xianbei was a dynamic process influenced by admixture with surrounding populations., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Traditional manufacturing industry is in the early stages of transition to low-carbon innovative production, and is in urgent need of a low-carbon innovation system to achieve the goal of carbon neutrality. In order to realize the effective supervision of enterprise carbon emissions, this paper constructs a tripartite evolutionary game model among the corporate, government and public from the perspective of dynamic subsidies and taxes. The main results are as follows. First, the increase in government subsidies to a certain extent will help encourage companies to choose low-carbon innovative production strategies, but more subsidies are not always better. Excessive subsidies will increase the cost of government regulation and reduce the probability of government regulation. Second, the tripartite evolutionary game system does not converge under the static subsidies and taxes mechanism. But the system could quickly converges to the stable condition under dynamic subsidies and taxes. The stable point is the situation of corporate low-carbon innovation, government regulation, and public supervision. Third, the public intervention and supervision can effectively prevent the phenomenon of government misconduct and enterprises over-emission production. And the influence of public reward and punishment is more effective for the government than for enterprises., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Previous studies about heavy metal (HM) accumulation in the surrounding areas affected by mining mainly focused on a single or just a few mining areas. However, these studies could not provide adequate information supporting HM controls in soils at the national scale. This study first conducted a literature investigation and collected HM data in mining areas in China from 263 pieces of published literature. Then, geo-accumulation index (I geo ), ecological risk index (ER), and health risk assessment model were adopted to evaluate their HM pollution, ecological risks, and health risks, respectively. Finally, Geodetector and Pearson correlation coefficients were used to explore the relationships between the spatial distribution patterns of HMs in soils and their influencing factors. Results showed that: (i) the average concentrations of Cd, Hg, Pb, Zn, Cu, As, Ni, and Cr were 5.4, 1.2, 335.3, 496.1, 105.8, 55.0, 42.6, and 72.4 mg kg -1 , respectively, in the surrounding areas affected by mining in China; Cd pollution in soils (I geo = 2.9) was most severe; Cd (ER Cd > 320) and Hg (ER Hg > 320) were the main ecological risk factors; (ii) among the selected factors, mine types, clay content, soil organic carbon, and precipitation with the highest relative importance for the spatial distribution patterns of the HMs; (iii) HM accumulation were inversely proportional to soil pH, and were proportional to clay content, precipitation, and temperature; (iv) As, Cd, Hg, Pb, and Ni should be selected as the HMs to be controlled preferentially; (v) priority attention should be given to mining areas in Central South China, Southwest China, Liaoning province, and Zhejiang province; (vi) special attention should be given to mining areas of antimony, tin, tungsten, molybdenum, manganese, and lead‑zinc. The above results provided crucial information for HM control in the areas affected by mining at the national scale., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Previous studies about the effects of mining on the potentially toxic elements (PTEs) in the surrounding soils mainly focused on single or few mining areas. However, these studies couldn't comprehensively quantify the mining-induced variations of soil PTE concentrations at the national scale. Moreover, the quantitative relationships between the effects of mining on soil PTEs and some related factors remained unclear at the national scale. This study first conducted a literature survey for soil PTE data affected by mining in China. Then, the random-effects model in the meta-analysis was used to quantify mining-induced variations of soil PTE concentrations in the surrounding areas. Last, the single meta-regression was used to explore the relationships between the effects of mining on soil PTEs and the related factors at the national scale. Results showed that: (i) mining-induced increases of soil PTE concentrations followed the order: Cd (1017%) > Hg (319%) > Pb (291%) > Zn (176%) > Cu (129%) > As (92%) > Ni (23%); (ii) mining-induced increases of soil PTE concentrations in clay (531%), non-ferrous mine (188%), paddy field (212%), and Central South China (290%) were more than those in other soil textures, mine types, land-use types, and geographical divisions, respectively; (iii) the effects of mining on soil PTEs were negatively correlated with soil pH (Q M = 29.76, p < 0.01) and positively correlated with soil organic carbon (Q M = 28.54, p < 0.01) and mean annual precipitation (Q M = 91.75, p < 0.01); (iv) the effects of mining overall decreased with the sampling year (Q M = 35.01, p < 0.01) and showed latitudinal zonality (Q M = 180.39, p < 0.01). The above results provided valuable information for soil PTE mitigation in the areas affected by mining in China., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Since 1998, China has gradually moved toward voluntary uncompensated blood donation. In some cities, the shortage of platelets has been noticeably severe. Mutual assistance that collects blood from one's family and social networks is a potential solution. The measure, however, turned out problematic. There are donors who choose to donate platelets over whole blood without compensations, and donate platelets directly to blood banks instead of via the mutual assistance system. This study explores reasons behind their choices qualitatively., Methods: This report is based on data conducted from January to February 2018; 25 uncompensated regular platelet donors were interviewed. The blood component donation service team in Guangzhou facilitated the data collection process and referred prospectively eligible blood donors to our research team. The interviews took about 30 min to two hours to complete. The qualitative data were analyzed by using the software ATLAS.ti 8., Results: Platelet donation takes a much long time than whole blood donation and requires complicated processes. It may also cause discomfort as the other blood components are returned to the body, causing physical and psychological distress due to worries about contamination. Thus, platelet donation tends to involve higher time and psychological costs than whole blood donation. Yet, it has short collection intervals that allows for more frequent donations, and urgency of a severer shortage than whole blood. Hence, regular platelet donors may feel higher significance in platelet donation than whole blood donation, with the belief that more lives would be saved. Some whole blood donors thus switched to become platelet donors. Mutual assistance blood donation was not chosen by the participants for platelet donation, because such donations may exert moral pressure to both the donors and recipients. Furthermore, "acquaintance" has been loosely defined; the system has sometimes been manipulated to become profit-making monetary transactions. It hence failed., Conclusions: The practice of platelet donation reinforces the understanding that blood donation is a gift giving process performed among strangers. A safe and sustainable voluntary blood supply can only be secured in the absence of monetary transactions and moral pressure.

Objective: Lumbar disc herniation (LDH) is a common and frequent orthopedic disease with strong genetic determinants. The disruption of the intervertebral disc extracellular matrix has been found to play a key role in the development of LDH, suggesting that abnormal matrix metalloproteinases (MMPs) may promote the degradation of the disc matrix. MMP-9, an important member of the MMP family, is a good candidate for the LDH susceptibility gene. The present study aimed to investigate the association of common variants in the MMP-9 gene with the risk, severity, and clinical characteristic variables of LDH., Materials and Methods: Fourteen tag single nucleotide polymorphisms (SNPs) entirely covering the region of the MMP-9 gene were analyzed in a sample of 845 patients and 1751 healthy controls., Results: The SNP rs17576 was found to be significantly associated with susceptibility to LDH (OR = 0.77, p = 0.0002), which was also confirmed by haplotype-based analyses (rs79845319-rs17576-rs45437897, global p < 0.001). Our results indicated that the A allele of rs17576 reduced the risk of LDH by ∼23% on average. Furthermore, the G allele of rs17576 was found to correlate with more severe grades of disc degeneration., Conclusion: Our results provide additional evidence supporting an important role of the MMP-9 gene in the pathogenesis of LDH.

Background: Patients with end-stage renal failure (ESRF) need integrated health care to maintain a desirable quality of life. Studies suggest that post-discharge nurseled telephone support has a positive effect for patients suffering from chronic diseases. But the post-discharge care is under-developed in mainland China and the effects of post-discharge care on patients with peritoneal dialysis have not been conclusive., Aim: The purpose of this study is to test the effectiveness of postdischarge nurse-led telephone support on patients with peritoneal dialysis in mainland China., Methods: A randomized controlled trial was conducted in the medical department of a regional hospital in Guangzhou. 135 patients were recruited, 69 in the study group and 66 in the control group. The control group received routine hospital discharge care. The study group received post-discharge nurse-led telephone support. The quality of life (Kidney Disease Quality of Life Short Form, KDQOL-SF), blood chemistry, complication control, readmission and clinic visit rates were observed at three time intervals: baseline before discharge (T1), 6 (T2) and 12 (T3) weeks after discharge., Results: Statistically significant effects were found for symptom/problem, work status, staff encouragement, patient satisfaction and energy/fatigue in KDQOL-SF and 84-day (12-week) clinic visit rates between the two groups. The study group had more significant improvement than the control group for sleep, staff encouragement at both T2 and T3, and pain at T2 and patient satisfaction at T3. No significant differences were observed between the two groups for the baseline measures, other dimensions in KDQOL-SF, blood chemistry, complication control, readmission rates at all time intervals and clinic visit rates at the first two time intervals., Conclusions: Post-discharge nurse-led telephone support for patients undergoing peritoneal dialysis is effective to enhance patients' well-being in the transition from hospital to home in mainland China., (Copyright © 2014 International Society for Peritoneal Dialysis.)

Severe acute respiratory syndrome (SARS) caused by SARS-associated coronavirus (SARS-CoV) is a fatal disease. Prevention of future outbreaks is essential and requires understanding pathogenesis and evolution of the virus. We have isolated a SARS-CoV in China and analyzed 47 SARS-CoV genomes with the aims to reveal the evolution trends of the virus and provide insights into understanding pathogenesis and SARS epidemic. Specimen from a SARS patient was inoculated into cell culture. The presence of SARS-CoV was determined by RT-PCR and confirmed by electron microscopy. Virus was isolated followed by the determination of its genome sequences, which were then analyzed by comparing with other 46 SARS-CoV genomes. Genetic mutations with potential implications to pathogenesis and the epidemic were characterized. This viral genome consists of 29,728 nucleotides with overall organization in agreement with that of published isolates. A total of 348 positions were mutated on 47 viral genomes. Among them 22 had mutations in more than three genomes. Hot spots of nucleotide variations and unique trends of mutations were identified on the viral genomes. Mutation rates were different from gene to gene and were correlated well with periodical or geographic characteristics of the epidemic.

Environmental factors, phytoplankton biomass (Chl a) and primary production of two water areas in Daya Bay (Dapeng'ao Bay and Aotou Bay) were investigated during the transition period from spring to summer. Chl a ranged from 3.20 to 13.62 and 13.43 to 26.49 mg m(-3) in Dapeng'ao Bay and Aotou Bay respectively, if data obtained during red tides are excluded. Primary production varied between 239.7 and 1001.4 mg Cm(-2) d(-1) in Dapeng'ao Bay. The regional distribution of Chl a and primary production were mostly consistent from spring to summer in both bays. Seasonal transition characters have been found in Daya Bay from spring to summer, including high values of DO, nitrate and silicate. Size structures of phytoplankton and its primary production do not change very much from spring to summer, with micro-phytoplankton dominating and contributing about 50% of the whole. In Daya Bay, phytoplankton is limited by nitrogen in spring, and by phosphate in summer. Artificial impacts are evident from high temperature effluent from nuclear power stations, aquaculture and sewage. During the investigation, a red tide occurred in Aotou Bay, with a maximum Chl a of 103.23 mgm(-3) at surface and primary production of 2721.9 mg Cm(-2) d(-1) in the red tide center. Raised water temperature and nutrient supply from land-sources help to stimulate annual red tides.