Development of fouling communities on vertical structures in the Baltic Sea   总被引：6，自引：2，他引：6  

Susanne Qvarfordt  Hans Kautsky  Torleif Malm 《Estuarine, Coastal and Shelf Science》2006,67(4):618-628

The pillars of the bridge connecting the Island of Öland with the Swedish mainland were rebuilt between 1990 and 2000. The renovation produced pristine vertical concrete substrates, which became submerged in known years and seasons. The fouling communities on the pillars were examined in 2001 to determine whether the community structure could be explained in terms of either orderly successional development or of seasonal variation in the settlement of benthic organisms. As well, the communities on the pillars were compared to communities on the vertical surfaces of boulders in the area. The results indicated that an annual species composition is the final stage in the succession on the observed, vertical constructions. The few perennial species add to the variation between pillars as they increase in biomass (Polysiphonia fucoides) or become out-competed (Balanus improvisus). Also, observed seasonal differences in the biomass of these perennial species indicated that the time of year free space becomes available might be an important determinant of the future structure of the community. Comparison between the pillar and boulder communities showed that the artificial structures were not surrogates for the natural hard substrate: pillar communities differed in that they lacked most perennial algal species and had a high biomass of B. improvisus.  相似文献   

Effects of an area closed to fisheries on the composition of the benthic fauna in the southern North Sea     

Duineveld  Gerard C. A.; Bergman  Magda J. N.; Lavaleye  Marc S. S. 《ICES Journal of Marine Science》2007,64(5):899-908

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Community turnover provides insight into variable invertebrate recovery between restored streams with different integrated catchment management plans     

Sharon Elizabeth Graham  John Martin Quinn 《新西兰海洋与淡水研究杂志》2020,54(3):467-489

ABSTRACT

Understanding temporal patterns in restored environments is important for identifying potential barriers to recovery and improved management of degraded habitats. In this paper, we use temporal beta diversity analyses to compare invertebrate community recovery trajectories in three restored agricultural stream sites under different integrated catchment plans, a native forest reference site, and two unmodified pasture control stream sites over 24 years. The restored sites diverged from their initial community composition over time and became more similar to the reference site community, which was relatively stable over time. Variation partitioning showed that prior to restoration beta diversity was primarily associated with environmental and spatial drivers, whereas post-restoration beta diversity was more influenced by temporal and environmental drivers, including changes in substrate size, fine sediments, water clarity, and nutrients, as well as temperature and flow regime. Species’ contributions to beta diversity varied between sites and years, with sensitive EPT taxa contributing more in reference and control sites. However, contributions of some EPT species, particularly mayflies, increased in restored sites post-ICM. In summary, after nearly two decades of ICM, restored stream sites show recovery towards reference conditions, yet differences persist, indicating that rehabilitation may take longer, depending on the restoration goals.  相似文献   

Seasonal use of coastal resources by otters: Comparing sandy and rocky stretches     

Miguel Clavero  Jos Prenda  Miguel Delibes 《Estuarine, Coastal and Shelf Science》2006,66(3-4):387-394

Seasonal patterns of use of coastal resources by otters have been studied, simultaneously performing diet analyses and spraint counts (expressed as marking intensity, MI). In spite of the small size of the study area, two different sectors could be clearly identified, a sandy and a rocky one. The origin (freshwater or coastal) of most prey types could also be determined. Surveys were performed bimonthly and classified as autumn–winter (A–W) or spring–summer (S–S).In the sandy sector, eels, flatfish and grey mullets were more frequently consumed in A–W, while crayfish was more frequently consumed in S–S. None of the identified prey types in the rocky sectors showed different frequency of occurrence values between the two periods. In this sector otter fed mainly on coastal prey throughout the year, while in the sandy one there was a clear shift from coastal prey to freshwater ones in S–S. The decrease of coastal prey consumption in S–S in the sandy sector coincided with the lowest MI values, showing that in this period otters use coastal areas less intensely. Though shifts in otter diet and use of space in the sandy sector are probably influenced by the population dynamics of estuarine fish species and crayfish, the increased tourist disturbance during spring and summer in the sandy sector could be an important determinant of the observed patterns. Finally, the results show that MI can be used as a reliable measure of habitat use by otters, at least in small areas.  相似文献   

南海北部藻类粒级结构及色素成分对浮游植物吸收系数的影响   总被引：2，自引：0，他引：2       下载免费PDF全文

王桂芬  曹文熙  许大志  杨跃忠 《海洋学报》2007,29(1):38-48

在珠江口、广东沿岸及南海北部三个航次生物-光学数据的基础上,研究了色素打包效应和色素成分的变化对浮游植物吸收系数的影响,结果表明,两种因素对吸收系数都有较大的贡献,但在不同的水体它们的影响程度各有不同.对网采浮游植物含量较高的珠江口和广东沿岸的水体而言,色素打包效应较强,对675 nm处比吸收系数的贡献平均分别为40%和20%;对微型浮游植物占主导地位的南海北部航次的水体,打包效应较弱,对675 nm处比吸收系数的影响平均仅为6%.采用多元线性回归的方法对吸收光谱进行分析,发现除叶绿素a之外的辅助色素对吸收系数的贡献主要表现在蓝绿光波段,三个航次440 nm波长处对总吸收的贡献平均分别为44%,43%和53%,其中对珠江口和广东沿岸航次的水体主要是光合类胡萝卜素的吸收贡献,而对南海北部航次的水体除了光合类胡萝卜素以外还要受到光保护类胡萝卜素的影响.由于河口、近岸和外海水体藻类粒级结构和辅助色素成分对浮游植物吸收系数的贡献有明显的差异,在南海北部水体建立比较精确的生物光学模型时,需考虑藻类粒级结构及色素成分对浮游植物吸收系数的影响.  相似文献   

海鳗肌肉及鱼头营养成分的比较研究   总被引：5，自引：0，他引：5  

曾少葵  章超桦  蒋志红 《海洋科学》2002,26(5):13-15

对海鳗肌肉和头的营养成分进行分析研究的结果表明：海鳗肌肉和头的粗蛋白含量分别为19.6%和15.2%，第一限制氨基酸均为色氨酸（Trp）、氨基酸价分别为92和80；必需氨基酸分别各占氨基酸总量的45.5%和36.3%，谷氨酸(Glu)、天门冬氨酸（Asp）、丙氨酸（Ala）和甘氨酸（Gly）等呈味氨基酸在肌肉和头中的含量基本持平，两者均含有丰富的钙、磷等无机元素。从蛋白质和氨基酸的分析结果看，肌肉的营养价值比头高。  相似文献   

Composition and Useful Properties of Tailings of Marine Manganese Nodules and Crusts     

Zhimin Bai  John C. Wiltshire 《Marine Georesources & Geotechnology》2005,23(1):13-24

Marine manganese nodules and crusts, when processed, yield tailings which may be utilized for environmental and economic benefit. The key to the reasonable and effective utilization of these tailings lies in making a systematic appraisal of their composition and properties. This article gives an introduction to the investigation of manganese tailings properties. The tailings have a high iron and/or manganese content, high surface area, high porosity, and fine grain size. Some tailings have a high rare earth element content which is valuable. They may also have high SO₃, arsenic, and uranium contents which are harmful. Depending on the process used to produce the tailings, there will likely be some differences in chemical composition, mineral assemblages, surface area and adsorption capability, pore diameter and volume, density and pH. In assigning potentially beneficial applications for these tailings, these differences should be taken into account to optimize utilization.  相似文献   

坛紫菜中藻胆蛋白的性质与化学组成研究   总被引：10，自引：1，他引：10       下载免费PDF全文

高洪峰  曹文达  纪明侯 《海洋与湖沼》1993,24(4):350-355

坛紫菜(于1988年采自青岛太平角海区人工养殖筏上)的水溶性色素粗提物经过硫酸铵沉淀和羟基磷灰石(HA)柱层析后,分离出藻蓝蛋白(RPC)、藻红蛋白(RPE)和变藻蓝蛋白(APC)。在中性介质中,其吸收光谱和荧光发射光谱与文献报道基本一致;但在酸性(pH=3)或碱性(pH=12)介质中,吸收光谱较在中性介质中有明显改变,原有的荧光性质也消失。RPC和APC只分离到一种聚集体,但RPE有两种不同的聚集体。用SephadexG—100凝胶过滤方法测量藻胆蛋白的分子量分别为:RPC117000,APC112000,小分子RPE38000,大分子RPE232000。对三种藻胆蛋白的氨基酸分析的结果表明,三种藻胆蛋白中都是酸性氨基酸的含量大于碱性氨基酸的含量。  相似文献   

台湾南湾秋末冬初水螅水母类的组成与分布   总被引：4，自引：0，他引：4  

黄将修  张金标  连光山 《台湾海峡》2003,22(4):437-444

本文分析了2001年11月2～3日和12月8～10日在台湾南湾12个测站采集的表层和底层92份浮游动物样品,共鉴定水螅水母18种,其中8种是台湾周围海域的新记录.半口壮丽水母(Aglaura hemistoma)和四叶小舌水母(Liriope tetraphylla)为优势种,它们在11月和12月分别占水螅水母类总量的77％和94％以上.南湾水螅水母类的种类数和个体丰度均以12月(17种,3102×10~(-3)个/m~3)明显多于11月(6种,72×10~(-3)个/m~3).在冬季,外海高盐水团是影响水螅水母类分布的主要因素,盐度与水螅水母类多样性指数的相关关系显著,文章还比较了南湾与邻近海区水螅水母类的季节变化.  相似文献   

南极中山站大气气溶胶的化学组成及其来源的判别   总被引：1，自引：1，他引：1  

黄自强  暨卫东  杨绪林  黄荣坦  汤荣坤  于涛  张功勋 《台湾海峡》2003,22(3):334-346

从1998年3月7日至1999年11月23日历时21个月，在南极中山站连续采集89个海洋气溶胶样品，本文提供全部样品的13种化学元素Cu、Pb、Zn、Cd、Fe、Al、Mn、Cr、V、K、Na、Ca、Mg含量的实测值．研究表明中山站气溶胶化学成份的含量具有季节性变化的特征．通过相关分析、因子分析、富集因子等方法判别不同时间段中山站气溶胶化学成份的来源。  相似文献