Eiefsis Bay Anoxia: Nutrient Conditions and Benthic Community Structure

Abstract. The changes in the concentrations of silicate, phosphate, and inorganic nitrogen in Eiefsis Bay. an intermittently anoxic basin, arc described and related to the changes in the physical properties of the water. Winter convection resulted in a very small vertical gradient of temperature, salinity, oxygen, and nutrients. Stratification started to develop in May and persisted for about 6 months. High values of silicate, phosphate, and ammonia occurred during the anoxic conditions prevailing in summer. The vertical transport of particulate organic matter and decomposition of abundant pelagic and benthic organic matter during the summer produced a low oxygen level in the bottom layer below the pycnoclinc. A high sea water temperature and vertical stability contributed to the development of anoxic conditions during the summer in the near bottom layer and to mass mortality of benthic macrofauna. Also the Eiefsis Bay anoxia appears to have had significant ecological effects on many other marine species, including several of economic importance.     

大亚湾海域溶解游离氨基酸及其与环境的关系

对大亚湾海域溶解游离氨基酸(DFAA)的分布特征及其影响因素进行了研究。现场采样调查分别于1995年5月、11月和2000年4月进行。结果表明 :(1)大亚湾海域DFAA的含量较高 ,在0.69～4.73μmol/L之间 ,平均2.16±0.87μmol/L,可能主要源于较为旺盛的生物活动 ;(2)DFAA含量在海域的平面分布变化较大 ,垂直分布和季节及年变化不明显 ;(3)DFAA与海水中的DOC呈正相关、与叶绿素呈负相关关系 ,与TIN的相关性则呈季节变化 ,生物效应可能是影响该海域DFAA含量的主要因素。     

杭州湾北岸潮滩沉积物化学元素分布特征

本文根据杭州湾北岸潮滩30个站位沉积物的化学元素测定,对潮滩沉积物的化学特征,分布规律及其影响因素进行分析。发现潮滩沉积物中的微量元素存在明显的分带性,这种分带同沉积物的粒度、化学性质及其水动力条件有一定相关性。     

Modelling trace metal concentration distributions in estuarine waters

The concentration of dissolved organic carbon (DOC) was measured every few months from September 2000 through October 2001 at a coastal location in the center of Suruga Bay, Japan (34°51′N, 138°38′E). Water samples were collected three times per day (midday, night and predawn). DOC concentrations ranged from 91.3 to 45.2 μM C on the surface to 100 m depth. Diel variation in DOC concentrations, among the three sampling times, was greater in the upper 20 m, with a maximum difference of 21.7 μM C in July 2001, and reflected in diel DOC inventory variations from the surface to 50 m. Diel variations were controlled by both physical and biological factors. DOC concentrations were significantly correlated with potential density in the deeper layers (100–1000 m), indicating that the distribution of DOC concentrations in the deeper layer was mainly due to mixing. Most DOC concentrations in the upper layer (0–50 m) did not display the same relationship as in the deeper layer. Using the relationship with potential density at 100–1000 m, the DOC concentration in the upper layer, due simply to mixing, was calculated. The difference between the calculated and observed DOC was used to estimate biological contribution. The biological contributions to the DOC inventory in the upper layer (0–50 m) were found greatly in November 2000 and April 2001. This indicates that excess DOC accumulated, by biological processes, in the upper layer during these periods. In November 2000, the excess DOC in the inventory was constant throughout the sampling days (0.36–0.37 mol C m⁻²), whereas diel variations of DOC in the vertical profile were large and contrary to the variation between 10 and 20 m. This suggests that the excess DOC was contributed biologically during daytime in the uppermost layer and reached to the 50 m depth by deeper mixing. As a result, the inventory appeared to be stable over a day because of the compensating effects of DOC production and consumption throughout 50 m. In contrast, in spring and summer, there was a distinct diel inventory decrease in the nighttime, with apparent rates ranging from −0.61 to −0.35 μM C h⁻¹. It is probable that the DOC, which accumulated during the daytime, was mostly labile, with a turnover time of a few hours. The results indicate that the dynamics of diel DOC variations varied seasonally, and suggest that these variations need to be considered when estimating seasonal DOC pools in the coastal ocean.     

Dissolved inorganic carbon and CO2 fluxes across Jiaozhou Bay air-water interface

On the basis of data collected in the Jiaozhou Bay in June and July 2003, the DIC distribution in seawater is studied,and an average air-sea flux of CO2 is estimated. The results show that the content of DIC inside the bay is markedly higher than outside the bay in June, but the contem of DIC outside the bay is markedly higher than inside the bay in July. The trend of DIC distribution inside the bay is similar, viz. the content is the maximum in the northeast, then decreases gradually toward the west, and the content is the minimum in the west. The total trend of vertical distribution is to increase gradually from surface to bottom. This characteristic of DIC distribution is determined by Jiaozhou Bay hydrology and there is a close relation between DIC and particulate N.P. Average CO2 flux across the air-sea interface is 0.55 mol/(m^2.a) in June and 0.72 mol/(m^2.a) in July. Jiaozhou Bay is considered as a net annual source for atmospheric CO2 in June and July, and the total CO2 flux from seawater into atmosphere is about 740 t in June and 969 t in July.     

2001/2002年夏季南极普里兹湾及其邻近海域的浮游植物

报道了 2 0 0 1 /2 0 0 2年夏季南极普里兹湾邻近海域 3 7个大面测站浮游植物的调查结果。经初步鉴定共有浮游植物 3门 3 7属 86种 ,其中硅藻在种类和细胞丰度上占绝对优势 ,其次为甲藻。主要优势种为克格伦拟脆杆藻 (Fragilariopsiskerguelensis)、细条伪菱形藻 (Pseu do nitzschialineola)、短拟脆杆藻 (Fragilariopsiscurta)和赖氏束盒藻 (Trichotoxonreinboldii)等南极特有种类和常见种类。调查区浮游植物分为两个群集 ,分布在 6 7°S以南的普里兹湾内的群集主要以克格伦拟脆杆藻、短拟脆杆藻、胡克星脐藻 (Asteromphalushookeri)和南极弯角藻 (Eu campiaantarctica)等南极特有种类和常见种类为主 ;分布在 6 7°S以北的大洋海域的群集主要以细条伪菱形藻、赖氏束盒藻、拟膨胀伪菱形藻 (Pseudo nitzschiaturgiduloides)和羽状环毛藻(Corethronpennatum)等南极常见种为主。调查区浮游植物的平均细胞丰度为 (8796± 2 92 85 )ind/L ,细胞多分布于海水的表层 ,密集区分布在 6 7°S以南的普里兹湾内 ,浮游植物的细胞丰度同硝酸盐的浓度密切相关。调查区浮游植物的多样性程度是低的。     

胶州湾海水中溶解氨基酸的研究

于１９８６年１月－１１月用高效液相色谱法分析胶州湾１０个站位表层和底层海水中溶解游离氨基酸（ＤＦＡＡ）的组成、含量的分布及其季节变化。结果表明，７个站位的表层海水中月平均总溶解游离氨基酸（ＴＤＦＡＡ）含量范围为１．２４－２．２８ｕｍｏｌ／Ｌ。多数站位在２月份处于最低值（０．４ｕｍｏｌ／Ｌ），１１月份达最高值（５．０ｕｍｏｌ／Ｌ）。所测氨基酸中，Ｇｌｕ，Ｇｌｙ、Ａｒｇ、Ｌｅｕ，Ｏｒｎ，Ｓｅｒ等占优势     

杭州湾期间带生态学研究──Ⅰ．种类组成与分布

对杭州湾软相潮间带周年调查，共获底栖动物９５种，以甲壳动物（３４种）、鱼类（２８种）、软体动物（２１种）占绝对优势。生态类群以我国沿岸广温广盐性种和半成水特有种为主，生活方式多为活动性和埋栖类型。这与杭州湾水域盐度低且变化幅度大及动力作用强，底质不稳定等因素密切相关。从湾底到湾口，底栖动物种类增多，组成类群逐渐从低盐的河口种向广盐的海洋种演替，表现出明显的湾性分布。种类的垂直分布是中潮区大于低潮区大于高潮区，各类群生物在潮间带呈现随机镶嵌分布，无明显的分带现象。种数的季节分布呈现更、秋两季较多、冬季最少的特点。     

Intensification of Subtidal Surface Currents Over a Deep Channel in the Upper Chesapeake Bay

A three-dimensional hydrodynamic model of the Upper Chesapeake Bay was used to examine the nature and cause of an intensification of subtidal, southward surface current in the middle reaches of the basin. The deep navigation channel along the eastern boundary was found to be ultimately responsible. The deep channel allows the density and tidally-induced subtidal currents to intensify over it, producing the eastern intensification. Both mechanisms operate in the non-rotating limit and consequently do not diminish with vanishing effect of the earth's rotation. Density-induced forcing is predominantly baroclinic, generating a northward undercurrent in the deep channel and a southward current aloft which attenuates westward. Tidal forcing is mostly barotropic, producing southward mean current in the deep channel and return flow to the west. Historic data lend support to the model results.     

基于多种生物指数的中国渤海莱州湾海域底栖生境健康评价

As an important part of the Bohai economic rim, the Laizhou Bay has been stressed by serious eco-environmental problems in recent years. In this study, the Shannon-Wiener index(H′), AZTI's marine biotic index(AMBI) and the multivariate AMBI(M-AMBI) were used to assess the ecological quality status(EQS) of the Laizhou Bay according to macrobenthos data collected annually in August 2011–2014. The results showed that the overall benthic habitat quality in the Laizhou Bay was assessed as "Good". However, 25% of the samples were classified as"Moderate", "Bad" or "Poor" status under degraded conditions. Ecological group Ⅲ(EGⅢ) species which had a certain tolerance to environmental disturbances had a higher proportion in each station, and most of them had appeared the pollution indicator species Capitella capitata. This indicated that the benthic habitat in the Laizhou Bay had been disturbed and polluted to some extent. The comparison of the three indices evaluation result and the RDA analysis showed that the H′ and M-AMBI were more suitable when the relative abundance of the single species was high and the macrobenthic community was significantly imbalanced; when the relative abundance of opportunistic species(EGIV and EGV) was high, the AMBI and M-AMBI could reflected the EQS objectively; in an undisturbed and polluted environment, all the three indices could indicate the benthic habitats quality. In summary, the better correlation between the three indices and environmental factors showed that they were well responsive to the tendency of the benthic habitats quality in the Laizhou Bay.