Diurnal changes in the bio-optical properties of the phytoplankton in the Alborán Sea (Mediterranean Sea)

The changes in the phytoplankton absorption properties during a diurnal cycle were investigated at one station located in the north-western area of the Alborán Sea. The experiment was performed in spring when the water column was strongly stratified. This hydrological situation permitted the establishment of a deep chlorophyll a (chl a) fluorescence maximum (DFM) which was located on average close to the lower limit of the mixed layer and the nutricline. The relative abundance of pico-phytoplankton (estimated as its contribution to the total chl a) was higher in the surface, however, micro-phytoplankton dominated the community at the DFM level. Chl a specific absorption coefficient (a*(λ)) also varied with optical depth, with a* (the spectrally average specific absorption coefficient) decreasing by 30% at the DFM depth with respect to the surface. A significant negative correlation between the contribution of the micro-phytoplankton to the total chl a and a* was obtained indicating that a* reduction was due to changes in the packaging effect. Below the euphotic layer, a* increased three-fold with respect to the DFM, which agrees with the expected accumulation of accessory pigments relative to chl a as an acclimation response to the low available irradiance. The most conspicuous change during the diurnal cycle was produced in the euphotic layer where the chl a concentration decreased significantly in the afternoon (from a mean concentration of 1.1 μg L⁻¹ to 0.7 μg L⁻¹) and increased at dusk when it averaged 1.4 μg L⁻¹. In addition, a* and the blue-to-red absorption band ratio increased in the afternoon. These results suggest that a*(λ) diurnal variability was due to increase in photo-protective and accessory pigments relative to chl a. The variation ranges of a*(λ) at 675 and 440 nm (the absorption peaks in the red and blue spectral bands, respectively) in the euphotic layer were 0.01–0.04 and 0.02–0.10 m² mg⁻¹ chl a, respectively. Approximately 30% out of this variability can be attributed to the diurnal cycle. This factor should therefore be taken into account in refining primary production models based on phytoplankton light absorption.     

舟山枸杞水域的污损生物生态

本文系１９８８年９月～１９８９年９月在舟山枸杞乌里西岙水域进行挂板试验的结果。共获污损生物１３５种，其中，近岸的油库码头获７７种，远岸的养殖筏获１１０种。动物以亚热带高盐性种类为主，三角藤壶Ｂａｌａｎｕｓｔｒｉｇｕｎｕｓ、小海葵Ａｃｔｉｎｉａ、柯氏分胞孔苔虫Ｃｅｌｌｅｐｏｒｉｎａｃｏｓｔａｚｉｉ、西方三胞苔虫Ｔｒｉｃｅｌａｒｉａｏｃｃｉｄｅｎｔａｌｉｓ、艾氏美熄Ｃｌｔｉａｅｄｗａｒｄｓｉ、广口小桧叶螅Ｓｅｒｔｕｌａｒｅｌｌａｍｉｕｒｒｅｎｓｉｓ等占优势，藻类常见的有长石莼Ｕｌｖａｌｉｎｚａ、肠浒苔Ｅｎｔｅｒｏｍｏｒｐｈｙｉｎｔｅｓｔｉｎａｌｉｓ和日本多管藻Ｐｏｌｙｓｉｐｈｏｎｉａｊａｐｏｎｉｃａ。枸杞污损生物的附着期主要在夏季，附着量也以夏季最大。不同地点附着量的差异极大。夏季由于近岸三角藤壶大量附着，故生物量明显大子远岸，其他季节均是远岸大于近岸。夏季近岸三角藤壶的覆盖面积达１００％，生物量达１８１１９ｇ／ｍ２，占污损生物总生物量的９８％。故夏季是污损生物防除的主要季节，三角藤壶是防除的主要对象。与１９７５～１９７６年嵊山污损生物进行比较，发现两地污损生物的种类组成和群落结构极为相似，说明１０多年以来嵊山     

Deformation Patterns of an Accretionary Wedge in the Transition Zone from Subduction to Collision Offshore Southwestern Taiwan

Swath bathymetry data and seismic reflection profiles have been used to investigate details of the deformation pattern in the area offshore southwestern Taiwan where the Luzon subduction complex encroaches on the passive Chinese continental margin. Distinctive fold-and-thrust structures of the convergent zone and horst-and-graben structures of the passive margin are separated by a deformation front that extends NNW-ward from the eastern edge of the Manila Trench to the foot of the continental slope. This deformation front gradually turns into a NNE–SSW trending direction across the continental slope and the Kaoping Shelf, and connects to the frontal thrusts of the mountain belt on land Taiwan. However, the complex Penghu submarine canyon system blurs the exact location of the deformation front and nature of many morphotectonic features offshore SW Taiwan. We suggest that the deformation front offshore SW Taiwan does not appear as a simple structural line, but is characterized by a series of N–S trending folds and thrusts that terminate sequentially in an en-echelon pattern across the passive Chinese continental slope. A number of NE–SW trending lineaments cut across the fold-and-thrust structures of the frontal accretionary wedge and exhibit prominent dextral displacement indicative of the lateral expulsion of SW Taiwan. One of the prominent lineaments, named the Yung-An lineament, forms the southeastern boundary of the upper part of the Penghu submarine canyon, and has conspicuous influence over the drainage pattern of the canyon     

胶州湾东北部岸滩改造方案的讨论

本文根据胶州湾东北部岸滩目前污染严重、脏乱不堪的现状及城市总体规划的要求.提出了胶州湾东北部岸滩的改造意见.着重从海洋动力、生态、水量平衡的角度论证了改造工程的必要性和可行性。     

海水中砷标准物质的研制

本文介绍了海水中砷标准物质的研制过程，其中包括溶液的配制、均匀性和稳定性检验，标样的分析方法。并对标准物质的定值数据进行统计处理，两种浓度的定值结果分别为：１．００μｇ／ｃｍ３±０．０４μｇ／ｃｍ３和５１．０μｇ／ｄｍ３±２．６μｇ／ｄｍ３。两种浓度砷标准物质的稳定期均为一年     

正压浅海湍流运动的雷诺应力封闭模型

根据湍流封闭理论,建立一种适用于正压浅海湍流运动的雷诺应力封闭模型(RSM),以代替目前三维浅海动力学模型中普遍采用的湍粘性系数的传统假设。通过直接建立并模化f—平面上正压海洋的雷诺应力传输方程,分别得到的微分形式和代数形式的RSM方程组。并讨论了进行数值计算所需要的边界条件。利用该模型可以进一步研究浅海潮流、风暴潮流及风海流等浅海流动的三维结构和湍流特性。     

秦山核电站邻近水域浮游植物的生态研究

本文分析了秦山核电站邻近水域生态零点调查四个航次的浮游植物样品,结果表明:调查区浮游植物的种数和细胞密度在时间尺度上均存在明显的季节变化趋势:夏大于秋大于春大于冬,并且与环境因子的变化密切相关,其中最主要的影响因子是温度、盐度和径流,而影响日变化的环境因子主要是潮汐。     

春季东海不同水域的表层叶绿素含量

利用１９９４年春季在东海及台湾海峡首次获得的表层水中绿素含量大面走航连续观测资料，结合温盐分布及以往的有关东海及台湾海峡的海流和上升流的结论，分析了春季东海表层叶绿素含量在不同水域的分布特征。结果表明，叶绿素含量分布与水文结构关系密切。叶绿素含量值随不同海流流域而变，但在各海流流域内基本不变，黑潮表层水的叶绿素含量最低，其次是台湾暖流表层水，长江冲淡水与江浙沿岸流域的叶绿素含量较高；黑潮西侧弱流剧     

春季东海表层水叶绿素a含量分布特征

依据“科学一号”调查船１９９４年４月在东海１０个断面上所进行的表层水连续走航观测资料，研究东海表层水叶绿素α含量在不同空间尺度上的分布特征和变化规律。结果表明，叶绿素α含量在陆架区高，在外海低；测区南部海域的含量一般高于北部海域。叶绿素α含量的分布形态变化很大，在某些外海深水区，叶绿素α含量连续百科公里没有显著变化，变化幅度小于０．２ｍｇ‘ｍ＾３；而在某些近海浅水区，叶绿素α含量在不到１公里范围内