Diagenetic behavior of manganese in Tokyo Bay sediment

To understand the behavior of manganese in diagenetic processes in sediments of an enclosed bay which is similar to those of an estuary, chemical analyses have been carried out on both sediment and interstitial water of a core sample collected from Tokyo Bay. The results suggest that redistribution of manganese takes place within the sediment as a result of the dissolution of buried manganese oxides and hydroxides under reducing condition, the downward diffusion of Mn²⁺ through the interstitial water toward lower layers and then the precipitation of carbonate. The carbonate formed in the sediment contains managanese carbonate probably as a solid solution between calcitic calcium carbonate and manganese carbonate.     

Mass balance and sources of mercury in Tokyo Bay

The mass balance and sources of mercury in Tokyo Bay were investigated on the basis of observations from December 2003 to January 2005. Estimated input terms included river discharge (70 kg yr⁻¹) and atmospheric deposition (37 kg yr⁻¹), and output terms were evasion (49 kg yr⁻¹), export (13 kg yr⁻¹) and sedimentation (495 kg yr⁻¹). Thus, the outputs (557 kg yr⁻¹) considerably exceeded the inputs (107 kg yr⁻¹). In addition, the imbalance between the inputs and outputs of mercury was much larger than that of other trace metals (Cd, Cr, Cu, Pb and Zn), which suggests that there are other major inputs of mercury to Tokyo Bay. The mercury concentrations in rivers correlated significantly with the concentrations of Al and Fe, major components of soil. In Japan, large amounts of organomercurous fungicides (about 2500 tons as Hg) were used extensively in fields in the past, and most of the mercury was retained in the soil. In this study, the mercury concentration in rivers was measured primarily in ordinary runoff. These observations lead to the hypothesis that field soil discharged into stormwater runoff is a major source of mercury in Tokyo Bay. As a preliminary approach to validating this hypothesis, we measured the concentrations of mercury and other trace metals in river water during a typhoon. The mercury concentrations in stormwater runoff increased to 16–50 times the mean value in ordinary runoff, which is much higher than the increases for other metals. This tends to support the hypothesis.     

Long-term change in the status of water pollution in Tokyo Bay: recent trend of increasing bottom-water dissolved oxygen concentrations

Journal of Oceanography - Long-term trends of bottom-water concentrations of dissolved oxygen (DO), total nitrogen, and total phosphorus at 42 sites in Tokyo Bay were analyzed using monthly data...     

Distribution and sources of heavy metals in the sediment of Xiangshan Bay

Heavy metals in the surface sediments and sediment core from the Xiangshan Bay, a mariculture base on the coast of the East China Sea, were determined by inductively coupled plasma mass spectrometry(ICP–MS) in order to evaluate their levels and sources. The results showed that the levels of Cu, Pb, Zn, and Cr in the sediments of the bay have been generally influenced by anthropogenic inputs since the founding of the People's Republic of China. In particular, Cu and Zn were polluted to some extent, as evidenced by high enrichment factors. Organic matter, grain size, wastewater discharge, and low energy hydrodynamic environment played dominant roles in the heavy metal enrichment in the sediments. The ratio of terrigenous source to marine biogenic deposit of trace metals in the sediments was calculated, revealing that terrigenous inputs were the main source of Cu, Pb, and Zn, while biological pellets contributed much more to the enrichment of Cr and Cd. Considering the influence of biological sources on the enrichment of Cd and Cr, and the fact that the sediment has been polluted by Cu and Zn, the development of mariculture and discharge of wastewater into the Bay should be restricted.     

Identification of Pb sources in Yellow Sea sediments using stable Pb isotope ratios

Rapid economic developments in East Asian countries have inevitably resulted in environmental degradation in the surrounding seas, and concern for both the environment and protection from pollutants is increasing. Identification of sources of contaminants is essential to environmental pollution management. In this study, the provenance of anthropogenic lead (Pb), a major pollutant of Yellow Sea sediments, was determined for river mouth sediments, including those of the Changjiang, Huanghe, Han, and Geum Rivers, and for age-determined shelf core sediments through the measurement of Pb isotope ratios in the HCl-leached fraction using multi-collector inductively coupled plasma-mass spectrometry (MC ICP/MS). Anthropogenic Pb has accumulated in shelf core sediments since 1910, and its isotope ratios were estimated as 0.863–0.866 and 2.119–2.125 for ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb, respectively, from the mixing relationships of the two endmembers. River mouth sediments exhibited enough distinction in anthropogenic Pb isotope ratios to be discriminated: 0.874 (2.144) in the Huanghe, 0.856 (2.129) in the Han, 0.857 (2.122) in the Geum, and 0.854 (2.101) in the Changjiang for ²⁰⁷Pb/²⁰⁶Pb (²⁰⁸Pb/²⁰⁶Pb), respectively. Although isotope ratios of geogenic Pb in sediments dating before 1910 showed narrow ranges (0.842–0.845 and 2.088–2.100 for ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb, respectively), distinct isotope ratios in each core permitted source identification of sediments in the Yellow Sea based on geographic locations and the geogenic Pb of each river. By comparing the isotope ratios of the estimated anthropogenic Pb to source-related materials, the provenances of anthropogenic Pb in Chinese river sediments were presumed to be Chinese coal or ore, which is also a major source of atmospheric particulate Pb. The anthropogenic Pb in the shelf core sediments in the northern Yellow Sea originated from northern Chinese cities such as Beijing and Tianjin through atmospheric pathways. Pb isotope ratios indicated that Pb in Korean river sediments was characteristic of local Korean ores.     

渤海中部沉积物铅来源的同位素示踪

本研究对渤海中部表层和柱状沉积物中Pb的含量和同位素进行了分析,研究了其时空分布规律,并探讨了其物质来源。结果表明,表层沉积物中Pb的含量为14.54×10-6~59.42×10-6,其含量在渤海湾近岸、黄河口附近、研究区的东北部较高,而在研究区的中部和渤海湾北部含量较低;Pb同位素207Pb/206Pb的值为0.8341~0.8489,208Pb/206Pb的值为2.0828~2.0980。岩心沉积物中Pb含量、同位素组成与表层沉积物相似,整体上较为稳定,但在1990s以来呈现增大的趋势。渤海中部沉积物中Pb以自然来源为主,黄河沉积物是其主要物质来源,但渤海湾北端则与滦河源物质或沿岸侵蚀相关;人类活动影响主要出现在1990s以后,与中国含Pb矿石的燃烧等工业活动相关,但影响微弱,仅在黄河口西北近岸海域、渤海湾等个别站位得到体现。     

伶仃洋表层沉积物特征及其泥沙运移趋势

根据伶仃洋表层沉积物的粒度分析资料,探讨表层沉积物的特征,并在此基础上应用Gao-Collins粒径趋势分析方法(GSTA模型)分析了伶仃洋表层沉积物的泥沙净输运趋势。结果表明,伶仃洋表层沉积物共有6种类型,其中以黏土质粉砂分布最广泛。受径流、潮流、波浪和陆架水入侵等多种动力作用,伶仃洋表层沉积物颗粒在北面最粗,南面次之,中间最细,东面略粗,西面略细;分选由中部向东、西两岸逐渐变好,但总体分选差;不同级配的泥沙分布和沉积特征存在差异。伶仃洋泥沙运移规律较复杂,泥沙呈现出向西南输运的总趋势;内伶仃洋四周泥沙受各种力作用,呈现出顺时针方向的环流运移,中心区域为最大浑浊带,泥沙以垂直落淤为主。淇澳岛以南至澳门半岛以东海域受粉砂和黏土向西扩散影响,泥沙向西运移。大屿海峡及外伶仃岛附近海域为高盐水入侵通道,泥沙向西北运移。     

杭州湾及其邻近海域表层沉积物的沉积环境分区及重金属污染特征分析

于2017年春季和2018年春季,分两个航次,在杭州湾及其邻近海域采集了表层沉积物样品,并对其粒度组成及重金属含量进行了测定。结果表明,研究区域表层沉积物的粒级组成以砂和粉砂为主,平均占比分别为38.0%和55.4%。根据粒级组成的区域分布特征,将研究区域分为长江河口现代沉积区(Ⅰ-1)、钱塘江河口现代沉积区(Ⅰ-2)、长江羽状锋面积聚区(Ⅱ-1)、长江次级锋面积聚区(Ⅱ-2)、岛屿风化影响区(Ⅲ)、残留砂混合沉积区(Ⅳ)等4大类6个亚区。通过比较不同区域重金属含量发现,总体分布趋势为Ⅱ-1区和Ⅱ-2区含量较高,Ⅰ-2区和Ⅳ区含量较低,Ⅰ-1区和Ⅳ区相对居中。单因子污染指数评价结果显示,Ⅱ-1区和Ⅱ-2区的Cu、Pb、Zn、As、Cd、Hg已呈现出污染态势,需引起关注;Cr则未呈现出污染态势。     

福建诏安湾海域表层沉积物粒度特征及输运趋势分析

通过对诏安湾海域6个站位的水文泥沙观测和181个表层沉积物样品的粒度分析,结合海湾水深地形,应用Gao?Collins粒径输运模型和系统聚类分析方法,分析研究了福建诏安湾海域的粒度参数分布特征、表层沉积物的运移趋势和沉积环境划分及其动力机制.结果表明,诏安湾表层沉积物共6种类型,以黏土质粉砂和砂为主,平均粒径介于0.5...     

渤海湾西部表层沉积物粒度及黏土矿物特征分析

对渤海湾西部海域和西岸入海河流中76个表层沉积物样品进行粒度及黏土矿物分析,研究表明该区有3种沉积物类型,黏土质粉砂分布于整个研究区,约占表层样的90%,是研究区最主要的沉积物类型;研究区黏土矿物以伊利石为主,黏土矿物组合为伊利石-高岭石-绿泥石-蒙皂石;渤海湾西部表层沉积物主要来源于海河等渤海湾西岸入海河流中的陆源碎屑物,滦河对研究区基本没有影响,黄河对研究区的影响变得比较小。对于研究渤海湾西岸的沉积特征及沉积物物源、了解陆地河流对于研究区海洋沉积环境的影响有着一定的科学意义。     

Uranium in coastal sediments of Tokyo Bay and Funka Bay

The sediment cores from Tokyo Bay and Funka Bay were analyzed for U and its isotopic ratio,²³⁴U/²³⁸U, after dissolving them in 0.1 M HCl, and 30% H₂O₂ in 0.05 M HCl. A small fraction of U in the anoxic sediments was dissolved in 0.1M HCl and even the added yield tracer,²³²U, was lost. The isotopic ratio of H₂O₂ soluble U in the sediments was equal to that of seawater, suggesting that the H₂O₂ soluble U in the sediments is authigenic. The 6M HCl solution dissolved part of the lithogenic U besides the authigenic U. The depth profiles of U from the two bays resembled each other. The authigenic U comprised more than half of the total U even at the surface and increased with depth down to 70 cm, showing small maxima at about 20 cm. The concentration of refractory U was nearly constant with depth and similar to that of the pelagic sediments. The highest U concentration, 6 µg g^–1 which was about 5 times that of the pelagic sediments, was observed in the layer between 70 and 160 cm depth in Tokyo Bay. The annual sedimentation rates of U in the Tokyo Bay sediments were 2.6 tons at the surface and 7.0 tons at the 70–160 cm depth. The increase in U with depth should be due to the deposition of interstitial U either diffusing downward from the surface indicating the trapping of seawater U, or otherwise diffusing upward from the deeper layer indicating the internal cycling of U within the sediments.     

罗源湾口柱状沉积物中的甲藻孢囊

通过时福建罗源湾口海域KMZK5柱状沉积物中甲藻孢囊的分析，共鉴定出15属30种甲藻孢囊，对比发现这30种甲藻孢囊是该湾以前未被记录的种类．其中12种是附近海域也未曾发现的种类，6种为有毒种类：缘亚历山大藻、小型亚历山大藻、塔玛亚历山大藻、具剌膝沟藻、链状裸甲藻、锥状斯氏藻，同时对甲藻孢囊的主要属种和有毒种类的丰度、分布在垂直方向上的变化特征进行了初步研究。     

Air-sea exchange of mercury in Tokyo Bay

In Tokyo Bay the concentrations of dissolved gaseous mercury (DGM) in the surface seawater and total gaseous mercury (TGM) over the sea were measured during December 2003, October 2004 and January 2005. Based on these data, the evasional fluxes of mercury from the sea surface were estimated using a gas exchange model. In addition, an automatic wet and dry deposition sampler was used to measure the wet and dry depositional fluxes of mercury from December 2003 to November 2004 at three locations in and near Tokyo Bay. The results indicate that the average DGM and TGM levels of seven locations are 52 ± 26 ng m⁻³ and 1.9 ± 0.6 ng m⁻³, respectively, which shows that the surface seawater in Tokyo Bay is supersaturated with gaseous mercury, leading to an average mercury evasional flux of 140 ± 120 ng m⁻²d⁻¹. On the other hand, the annual average wet and dry depositional fluxes of mercury at three locations were 19 ± 3 μg m⁻²yr⁻¹ and 20 ± 9 μg m⁻²yr⁻¹, respectively. These depositional fluxes correspond to the daily average total depositional flux of 110 ± 20 ng m⁻²d⁻¹. Thus, it is suggested that in Tokyo Bay, the evasional fluxes of mercury are comparable to the depositional fluxes.     

Seasonal variations of dissolved organic matter and nutrients in sediment pore water in the inner part of Tokyo Bay

At four stations in Tokyo Bay, pore water profiles of dissolved organic carbon (DOC), nitrogen (DON), phosphorus (DOP), and inorganic nutrients were determined at 3-month intervals over 6 years. Concentrations of dissolved organic matter (DOM) and nutrients were significantly higher in pore waters than in the overlying waters. Pore water DOC, DON, and DOP concentrations in the upper most sediment layer (0–1 cm) ranged from 246 to 888 μM, from 14.6 to 75.9 μM, and from 0.02 to 9.83 μM, respectively. Concentrations of DOM and nutrients in pore waters occasionally showed clear seasonal trends and were highest in the summer and lowest in the winter. The seasonal trends in the pore water DOM concentrations were coupled with trends in the overlying water temperature and dissolved oxygen concentration. Benthic effluxes of DON and DOP were low compared with those of inorganic nutrients, accounting for only 1.0 and 1.5 % of the total benthic effluxes of nitrogen and phosphorus, respectively; thus benthic DOM fluxes were quantitatively insignificant to the inorganic nutrient fluxes in Tokyo Bay. The DOM fluxes represented about 7, 3, and 10 % of the riverine discharge of DOC, DON, and DOP to Tokyo Bay, respectively.     

莱州湾07钻孔沉积物晚更新世以来的元素地球化学特征

在莱州湾南岸的07孔岩心进行高分辨率采样的基础上,采用X荧光光谱法(XRF)、离子质谱法(ICP-MS)以及原子荧光光谱法(AF)等方法测试了研究区07孔的48种常微量元素以及稀土元素的含量,并对元素相对含量、随深度变化规律、特征比值以及稀土元素配分模式进行了研究。结果表明,07孔主要元素及特征比值在海陆地层分界处有明显变化,可以作为地层划分的指标之一。其中,Mn、Mg、Ca、Fe、Mg/Ca及K/Na等对沉积环境响应比较明显,Ba、Zr、Rb、Si/A1、Ti/A1和Rb/Sr对源区的母岩类型、风化程度及搬运距离的变化敏感;07孔常微量元素垂向变化较大,在3次海侵地层中呈明显变化,并对应多个峰值。化学元素的变化规律所反映的地层特征与晚更新世以来的气候和海平面的变化有较好的对应关系。07孔不同深度沉积物的稀土元素球粒陨石标准化配分模式与黄河沉积物的相似,呈轻稀土元素富集的右倾型。说明黄河是莱州湾南岸弥河-潍河多源河流三角洲沉积体系的物源之一,且对莱州湾南岸一定深度范围内的沉积地层有部分贡献。     

Feeding of copepods on natural suspended particles in Tokyo Bay

Community grazing rates of copepods were estimated from data taken during three cruises in Tokyo Bay, based on bottle incubations and a temporal variation of gut fluorescence. Special attention was paid to the feeding selectivity in the estimations. Differential grazing was observed in the copepod communities:Acartia omorii, abundant in February, selectively fed on the particles of dominant size classes, whileOithona davisae, dominant throughout the year, andCentropages abdominalis selected large particles (>20µm). The maximum filtering rates on certain size classes were several times the average. In addition, a 34-hr investigation of the gut fluorescence of copepods revealed nocturnal feeding inParacalanus spp.,Pseudodiaptomus marinus andOithona davisae.Copepod communities collected with a net (95-µm mesh opening) were estimated to graze, in February 3.0%, in August 3.1–4.5% and in November 4.2–11.9% of the standing crops of phytoplankton or suspended particles per day.     

杭州湾底泥得克隆污染状况及来源的初步研究

随着含溴阻燃剂的进一步限用或禁用,氯代阻燃剂得克隆(Dechlorane Plus, DP)以其良好的热稳定性和电化学性能成为推荐的替代品之一。作为添加型氯代阻燃剂,DP很容易从产品中脱落而成为环境中广泛存在的污染物,但相关的研究仍十分匮乏。本研究测定了杭州湾海域4个底泥柱状样品中DP的残留及异构体特征,并对DP在该海域底泥中的时空分布和可能来源进行了初步分析。结果表明,syn-DP和anti-DP在底泥样品中的含量分别为BDL~17.7 pg/g干质量(平均为2.9±3.2 pg/g干质量)和1.4~38.1 pg/g 干质量(平均为8.0±8.5 pg/g干质量),其污染程度相对全球范围处于较低水平。空间分布表明金山工业区可能对杭州湾DP的污染有一定贡献,DP在柱状底泥中的垂直分布未发现明显变化趋势。本研究中DP的f_syn平均值为0.25~0.28,表明研究海域底泥中的DP可能来自于远距离传输。     

桑沟湾长牡蛎生物沉积物对环境底质影响的同位素证据

贝类通过生物沉积作用加速了养殖海区水体中的颗粒物质向海底的输送。在桑沟湾中筏式养殖的长牡蛎(Crassostrea gigas),将大量的有机物以生物沉积物(真粪和假粪)的形式排向养殖区海底。为完成对桑沟湾筏式养殖长牡蛎生物沉积物对环境底质影响的量化研究,作者通过在桑沟湾内不同的海区设置采样点(5个养殖区,3个对照点),对采样点SG 2与SG 6两个点的长牡蛎生物性沉积物与海区悬浮颗粒物进行了稳定同位测定及有机物来源分析。实验结果表明:选取的采样点沉积物稳定碳氮同位素丰度集中于δ~(13)C–22.82‰~–21.62‰,δ~(15)N 4.73‰~6.21‰。在SG 2点的悬浮颗粒物中,长牡蛎生物性沉积物贡献有机物占9.95%,对照区沉积物与SG 2区沉积物贡献分别为54.19%和35.86%。在典型的采样点,稳定同位素法能较准确地量化出各有机物来源的贡献比例。以SG C点为对照,其余7个采样点长牡蛎生物性沉积物有机物贡献在4.06%~28.64%,平均贡献率为13.96%±8.62%,牡蛎养殖已经对桑沟湾底质造成了一定的影响。     

渤海湾肠道病毒的季节分布及其污染类型分析

肠道病毒是一类水传播胃肠道疾病的重要病原体。为了解感染性肠道病毒在海水环境中的季节分布规律、污染类型以及与流行病学的关系,于2010年12月到2011年10月应用能够提供病毒感染性信息的细胞培养结合实时定量PCR（ICC-qPCR）方法,分4个季节对渤海湾天津近岸海域表层海水中肠道病毒进行了监测。500 mL海水经超滤浓缩,48 h细胞培养,然后用qPCR检测得到四季海水样品中感染性肠道病毒的浓度为0.2~196 PFU/L,平均值为60 PFU/L,其中夏季和秋季肠道病毒浓度较高,其平均值分别为82 PFU/L和110 PFU/L。秋季阳性检出率最高（85.7%）,其次是冬季（71.4%）。经测序分析,其主要污染类型是脊髓灰质炎 Ⅰ 型疫苗株,此外,还检测出危及公众健康的一株类口服脊灰 Ⅰ 型疫苗脊灰和一株脊灰疫苗衍生株。由此可见,肠道病毒的季节分布和主要污染类型与临床上的流行趋势基本一致,海洋作为一个天然的受纳水体为病毒提供了良好的栖息场所和传播机会,对公众健康存在着潜在的威胁。因此,为减少相关疾病的暴发,应重点加强肠道病毒流行季节的海洋水质监测。