三门湾夏季浮游植物现存量和初级生产力

该海区的生物、化学、水文等项目进行调查。用HQM-1型有机玻璃采水器采集水样,大面观测站仅采集表层(0～1m)水样,用于测定叶绿素a质量浓度和光合作用速率。在N2和N11两个连续观测站,每隔3h采集表层和5m层的水样,用于分析叶绿素a质量浓度及营养盐浓度。同时,用浅 型浮游生物网由近底层向表层垂直拖网采集浮游植物样品,所采样品被装入容积为600cm3的塑料瓶中,并加入20cm3的福尔马林溶液固定保存,供对浮游植物细胞计数和种属鉴定之用。营养盐样品用经酸预清洗过的孔径为0.45μm的醋酸纤维膜过滤,滤液用饱和HgCl2溶液固定后,低温避光保存。图…     

Cyclone formation and development in the Antarctic Prydz Bay

Using meteorological data of field observation in 1990 - 2000, especially polar orbit high-resolution NOAA satellite cloud maps received from the Antarctic expedition vessel since 1997, the formation and development of the Prydz Bay cyclone are studied in this paper. Some new viewpoints are suggested such as: when surround-polar cyclone enters the Prydz Bay, it can also intensify and develop in summer; cyclone can also develop in the easterlies in this bay. These view points revise old uncom-plete view point that the Prydz Bay is a burial ground of cyclone, and also further consummate formation-development theory of surround-cyclone in the Antarctic westerlies and cyclone in the Antarctic easterlies. In this paper, the mechanism of ice-air-sea interaction in the Prydz Bay is studied, and the physical process of cyclone formation-development is explained. By use of wholly dynamic transportation method, an energy exchange case of a cyclone, which explosively developed after entering the Prydz Bay, is calcu     

Deposition Rates of Terrestrial and Marine Organic Carbon in the Osaka Bay, Seto Inland Sea, Japan, Determined Using Carbon and Nitrogen Stable Isotope Ratios in the Sediment

Carbon and nitrogen stable isotope ratios (¹³C and ¹⁵N) of surface sediments were measured within Osaka Bay, in the Seto Inland Sea in Japan, in order to better understand the sedimentation processes operating on both terrestrial and marine organic matter in the Bay. The ¹³C and ¹⁵N of surface sediments in the estuary of the Yodo River were less than –23 and 5 respectively, but increased in the area up to about 10 km from the river mouth. At greater distances they became constant (giving ¹³C of about –20 and ¹⁵N about 6). It can be concluded that large amounts of terrestrial organic matter exist near the mouth of the Yodo River. Stable isotope ratios in the estuary of the Yodo River within 10 km of the river mouth were useful indicators allowing study of the movement of terrestrial organic matter. Deposition rates for total organic carbon (TOC) and total nitrogen (TN) over the whole of the Bay were estimated to be 63,100 ton C/year and 7,590 ton N/year, respectively. The deposition rate of terrestrial organic carbon was estimated to be 13,200 (range 2,000–21,500) ton C/year for the whole of Osaka Bay, and terrestrial organic carbon was estimated to be about 21% (range 3–34) of the TOC deposition rate. The ratio of the deposition rate of terrestrial organic carbon to the rate inflow of riverine TOC and particulate organic carbon (POC) were estimated to be 19% (range 3–31) and 76% (range 12–100), respectively.     

深圳湾北岸泥滩大型底栖动物次级生产力研究

根据2005年3、6、9月和12月在深圳湾北岸泥滩9个取样站采集的大型底栖动物4个季度的定量样品,运用Brey(1990)的经验公式进行了大型底栖动物栖息丰度、生物量、次级生产力和P/B值的研究计算.整个研究区域大型底栖动物年次级生产力平均值(去灰干重)为54.55g/(m2.a),其中观鸟屋附近泥滩(A断面)较高,为68.85g/(m2.a),凤塘河口附近泥滩(H断面)为50.62g/(m2.a)次之,沙嘴码头附近泥滩(F断面)较低,为44.18g/(m2.a),深圳湾北岸泥滩大型底栖动物年平均P/B为2.95.可见,大型底栖动物次级生产力越靠近深圳河河口越低,这与越靠近深圳河河口,大型底栖动物个体越小、生活史更短的结果是一致的.     

Preliminary study on different nutrient pools supplies for the phytoplankton growth in the Jiaozhou Bay in China in the fall of 2004

The source and significance of two nutrients, nitrogen and phosphorous, were investigated by a modified dilution method performed on seawater samples from the Jiaozhou Bay, in autumn 2004. This modified dilution method accounted for the phytoplankton growth rate, microzooplankton grazing mortality rate, the internal and external nutrient pools, as well as nutrient supplied through remineralization by microzooplankton. The results indicated that the phytoplankton net growth rate increased in turn from inside the bay, to outside the bay, to in the Xiaogang Harbor. The phytoplankton maximum growth rates and microzooplankton grazing mortality rates were 1.14 and 0.92 d-1 outside the bay, 0.42 and 0.32 d-1 inside the bay and 0.98 and 0.62 d-1 in the harbor respectively. Outside the bay, the remineralized nitrogen (Kr=24.49) had heavy influence on the growth of the phytoplankton. Inside the bay, the remineralized phosphorus(Kr=3.49) strongly affected the phytoplankton growth. In the harbor, the remineralized phosphorus (Kr=3.73) was in larger demand by phytoplankton growth. The results demonstrated that the different nutrients pools supplied for phytoplankton growth were greatly in accordance with the phytoplankton community structure, microzooplankton grazing mortality rates and environmental conditions. It is revealed that nutrient remineralization is much more important for the phytoplankton growth in the Jiaozhou Bay than previously believed.     

Measurements of suspended particulate matter with laser in-situ scattering and transmissometry in the Jiaozhou Bay in China

1 IntroductionKnowledge of suspended particle size and distri-bution is the key elements for better understandingthe sediment transport processes ( Wang et al.,2004), primary production (Ning et al., 2004),water quality controlling and pollution predictio…     

Short-term and interannual variability of redox-sensitive chemical parameters in hypoxic/anoxic bottom waters of the Chesapeake Bay

A combination of CTD casts, discrete bottle sampling and in situ voltammetric microelectrode profiling was used to examine changing redox conditions in the water column at a single station south of the Bay Bridge in the upper Chesapeake Bay in late July/early August, 2002–2005. Short-term (2–4 h) fluctuations in the oxic/suboxic/anoxic interface were documented using in situ voltammetric solid-state electrodes. Profiles of dissolved oxygen and sulfide revealed tidally-driven vertical fluctuations of several meters in the depth and thickness of the suboxic zone. Bottom water concentrations of sulfide, Mn²⁺ and Fe²⁺ also varied over the tidal cycle by approximately an order of magnitude. These data indicate that redox species concentrations at this site varied more due to physical processes than biogeochemical processes. Based on analysis of ADCP data, tidal currents at this station were strongly polarized, with the principal axis of tidal currents aligned with the mainstem channel. Together with the chemical data, the ADCP analysis suggests tidal flushing of anoxic bottom waters with suboxic water from north of the site. The present study is thus unique because while most previous studies have focused on processes across relatively stable redox interfaces, our data clearly demonstrate the influence of rapidly changing physical mixing processes on water column redox chemistry.Also noted during the study were interannual differences in maximum bottom water concentrations of sulfide, Mn²⁺ and Fe²⁺. In 2003, for example, heavy spring rains resulted in severe hypoxia/anoxia in June and early July. While reported storm-induced mixing in late July/early August 2003 partially alleviated the low-oxygen conditions, bottom water concentrations of sulfide, Mn²⁺ and Fe²⁺ were still much higher than in the previous year. The latter implies that the response time of the microbial community inhabiting the suboxic/anoxic bottom waters to changing redox conditions is slow compared to the time scale of episodic mixing events. Bottom water concentrations of the redox-sensitive chemical species should thus be useful as a tracer to infer prior hypoxic/anoxic conditions not apparent from ambient oxygen levels at the time of sampling.     

南大洋普里兹湾基于234Th/238U不平衡法的POC输出通量研究

中国第22次南极科学考察(2005年11月至2006年3月)期间,测定了南极普里兹湾海域5个站位的从表层至150 m水深的不同层位水样中溶解态和颗粒态234Th,238U的放射性比活度以及颗粒有机碳.利用234Th/238U在上层水体中的不平衡,计算了南极普里兹湾上层水体中234Th的平均停留时间和输出通量.结果显示,随着纬度的增加,上层水体中颗粒态和溶解态234Th的平均停留时间总体趋向减小,并在中纬度站位出现了最低值,分别为1~8和29~48 d,而颗粒态和溶解态234Th的输出通量则在中纬度站位出现了最大值,分别为21~38和26~39 dpm/(m3·d).运用箱型清除模式,利用两种不同的方法估算了各水柱中从真光层底部输出的POC通量,平均值分别达到104.7 mmol/(m2·d)(E法)和120.6 mmol/(m2·d)(B法),表明南极普里兹湾夏季存在很高的新生产力,它将会对该海域碳的生物泵过程产生重要作用.     

The impact of shrimp trawling and associated sediment resuspension in mud dominated, shallow estuaries

To address the relative importance of shrimp trawling on seabed resuspension and bottom characteristics in shallow estuaries, a series of disturbance and monitoring experiments were conducted at a bay bottom mud site (2.5 m depth) in Galveston Bay, Texas in July 1998 and May 1999. Based on pre- and post-trawl sediment profiles of ⁷Be; pore water dissolved oxygen and sulfide concentration; and bulk sediment properties, it was estimated that the trawl rig, including the net, trawl doors, and “tickler chain,” excavate the seabed to a maximum depth of approximately 1.5 cm, with most areas displaying considerably less disturbance. Water column profile data in the turbid plume left by the trawl in these underconsolidated muds (85–90% porosity; <0.25 kPa undrained shear strength) demonstrate that suspended sediment inventories of up to 85–90 mg/cm² are produced immediately behind the trawl net; an order of magnitude higher than pre-trawl inventories and comparable to those observed during a 9–10 m/s wind event at the study site. Plume settling and dispersion caused suspended sediment inventories to return to pre-trawl values about 14 min after trawl passage in two separate experiments, indicating particles re-settle primarily as flocs before they can be widely dispersed by local currents. As a result of the passage of the trawl rig across the seabed, shear strength of the sediment surface showed no significant increase, suggesting that bed armoring is not taking place and the trawled areas will not show an increase in critical shear stress.     

胶州湾夏季异养浮游细菌的时空变化规律及影响因素

2001年夏季对胶州湾异养浮游细菌在一个潮周期内的变化规律及影响因素进行了研究。结果表明,胶州湾异养浮游细菌数量的垂直分布特征是表层大于底层,表层平均8.99×109个/L,底层平均5.23×109个/L。胶州湾水体异养浮游细菌日变化幅度在表层水体较为明显,底层相对较小,但其变化规律均为最高值在小潮期而最低值出现在大潮期。浮游动物摄食、浮游植物光合作用产生的溶解有机物及水温和日光中的紫外辐射是影响胶州湾异养浮游细菌昼夜变化的主要因素,水交换是影响其日变化的主要因素。