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1.
Abstract. The oxygen consumption of Eudendrium glomeratum was measured monthly, throughout the period of active presence of the species in the field, to obtain indications on its physiological condition in the different phases of the cycle. Sets of one hundred polyps were assayed in the laboratory under normothermic (according to field temperature: 14–19°C) and hyperthermic conditions (22–25°C). The different response to identical temperatures at the extremes of the cycle, together with a differential ability to face stressful conditions in the same periods, suggests that other factors, besides temperature, regulate the seasonal cycle of Eudendrium glomeratum. 相似文献
2.
CB Untiedt 《African Journal of Marine Science》2016,38(1):S91-S104
The composition and distribution of macrobenthic communities was investigated in three areas in the KwaZulu- Natal Bight, a section of shelf off the east coast of South Africa. Areas were pre-selected on the basis of three known oceanographic features, posited to deliver land- or Agulhas Current-derived nutrients onto the shelf and to drive ecosystem functioning in this region. Replicate sediment samples were collected with a 0.2 m2 van Veen grab, during two surveys (A, B) corresponding with normal periods of high and low rainfall, respectively. A subset of the full station array was selected across the shelf in an arrangement of increasing depths (inner-, mid- and outer shelf) through each feature area to investigate the spatial distribution and feeding modes of macrobenthic taxa. The two periods showed some differences in abundance and numbers of macrobenthic taxa, but were not statistically different. Total macrobenthic abundance from Survey A was 20 215 individuals from 642 taxa, decreasing to 18 000 individuals from 503 taxa during Survey B. Polychaeta and Crustacea were the dominant taxa sampled; abundance of the latter was attributed largely to a proliferation of Paguristes sp.1 at inner-shelf samples in the midbight (Thukela) region during Survey B. Similarity classification distinguished seven sample groups reflecting differences in feature areas and shelf positions under investigation. The Thukela River midshelf community supported the highest macrobenthic abundance, while the midshelf off the southern bight (Durban region) was most species rich. Findings were attributed to the habitat complexity of the midshelf which includes a palaeo-dune cordon at the 60 m isobath. Functionally, the community was dominated by interface- and deposit-feeding fauna, emphasising the importance of trophic plasticity in an environmentally variable and heterogeneous shelf environment. 相似文献
3.
伊乐藻—草鱼圈养复合生态系统中水生生物的变化和影响 总被引：2，自引：1，他引：2
从细菌、浮游植物、浮游动物、底栖动物和有机碎屑等几个方面分析了养鱼对伊乐藻种植区(以下简称为有草区)和无草区水域环境的影响。结果表明:两个区域存在着显著的差异性。有草区由于生长着茂密的水生植被,对环境压迫的缓冲能力增强,水生生物的群落结构较为稳定,物种多样性指数高于无草区,有机物的沉降速率也大大低于无草区。与此相比,无草区对环境压迫的缓冲能力较差,水体浮游植物数量增加,富营养化加剧。通过本项实验可以看出,人工种植伊乐藻对养鱼区水质有着明显地控制作用,是发展生态渔业的一条有效途径。 相似文献
4.
A. A. Filippov 《International Journal of Salt Lake Research》1996,5(4):315-327
The macrozoobenthos was investigated at eight sites in the Aral Sea inshore zone and in the lower reaches of the Syrdaria river. In the sea, the benthos comprised bivalve molluscsSyndosmya segmentum Recluz andCerastoderma isthmicum Issel, gastropods fromCaspiohydrobia Starob., the polychaeteNereis diversicolor O.F. Müller and the crabRhithropanopeus harrisii tridentatus (Maitland). In the Syrdaria, MysidaeParamysis lacustris (Czern.) and GammaridaeDikerogammarus aralensis (Uljanin) were found. These taxa have not been recorded from the Sea since the 1970s. The total zoobenthos biomass and density varied between the investigated Sea areas from 92 to 582 g/m2 and from 1,600 to 39,000 ind./m2, respectively. Spatial and temporal salinity changes within the range 20–41 g/L did not affect macrozoobenthos composition and structure. The conclusion is that the benthic ecosystem of the Aral Sea was in a state of comparative stability from the middle of the 1980s to the middle of the 1990s. Analysis of the zoobenthos in the inshore zone is proposed as a convenient and accessible method for monitoring the status of the zoobenthos of the entire Aral Sea. 相似文献
5.
为了了解XX核电厂周边海域的生态环境状况,筛选潜在威胁核电厂冷源安全的致灾生物,分析影响致灾生物时空分布的主要环境因素,本研究于2018年进行了四个季节的生态调查。结果表明,研究海域浮游植物密度秋季最高,春季优势种为东海原甲藻,其他季节优势种为中肋骨条藻等硅藻。浮游动物密度夏季最高,以桡足类为主,春、夏季优势种还包括球型侧腕水母和薮枝螅水母。底栖动物的密度和生物量在秋季最高,优势种主要为豆形短眼蟹、长吻沙蚕和丝异须虫。浮游植物、浮游动物和底栖动物群落均在夏季最为稳定,群落多样性水平和物种丰度较高,且分布较为均匀。浮游植物群落的细胞丰度与悬浮物和磷酸盐的浓度正相关性最高。浮游动物的密度受温度和盐度的影响较大。底栖动物的群落分布主要受悬浮物和无机营养盐的浓度影响。本研究共筛选出17种威胁XX核电厂冷源安全的潜在致灾生物。海地瓜、棘刺锚参、海葵和球型侧腕水母的风险等级较高,其分布主要受温度和盐度的影响。后续工作中,XX核电厂应根据潜在致灾生物与环境因子的关系加强暴发机制研究、提升监测预警能力,并优化驱赶消杀技术和干扰体系,为核电厂冷源安全提供理论和技术保障。 相似文献
6.
Long-term changes of zoobenthic fauna and submerged vegetation in the shallow Lake Monterosi (Italy)
Benthic invertebrates and aquatic vegetation were investigated in the volcanic Lake Monterosi with the aim to define the stage of development reached during progressive modifications which occurred in the shallow lake. Increasing trophy and introduction of an exotic plant (Nelumbo nucifera) were the key-factors responsible for the rapid qualitative reduction of the macrophyte population and its modification to non rooted plants (Ceratophyllum demersum). The invertebrate fauna associated with macrophytes was found to be abundant, diversified (83 taxa) and characterized by high diversity and presence of bioindicators of mesotrophy. Although the zoobenthic community appeared to be positively influenced by the macrophyte-dominated stage, some negative effects of Nelumbo-colonization on the invertebrate fauna indicated that further growth of this plant would cause a rapid change in the lake. 相似文献
7.
从细菌、浮游植物、浮游动物、底栖动物和有机碎屑等几个方面分析了养鱼对伊乐藻种植区(以下简称为有草区)和无草区水域环境的影响。结果表明:两个区域存在着显著的差异性。有草区由于生长着茂密的水生植被,对环境压迫的缓冲能力增强,水生生物的群落结构较为稳定,物种多样性指数高于无草区,有机物的沉降速率也大大低于无草区。与此相比,无草区对环境压迫的缓冲能力较差,水体浮游植物数量增加,富营养化加剧。通过本项实验可以看出,人工种植伊乐藻对养鱼区水质有着明显地控制作用,是发展生态渔业的一条有效途径。 相似文献
8.
水文报道1987年河南封丘曹岗湖底栖动物的调查结果。该湖底栖动物主要由寡毛类8种, 水生昆虫47种和腹足类2种组成, 其中克拉泊水丝蚓和刺铗粗腹摇蚊群为优势种类, 平均密度为2087个/m2, 生物量为4.8690g/m2, 并与长江中游浅水湖泊中的底栖动物作了比较, 对某些环境因素与底栖动物种类组成、数量分布的关系也作了扼要的分析。 相似文献
9.
从2010年10月开始在太湖梅梁湾围隔内实验区实施了改性当地土壤技术,在研究其对水体富营养化和蓝藻水华长效控制作用的同时,重点研究了底栖动物群落对此技术的响应.研究发现:经过11个月的处理,相比对照区,实验区内软体动物的平均密度和生物量分别增长了124%和33.8%,底栖动物Margalef和Shannon-Wiener多样性指数分别增长了41.1%和18.5%.环境因子和底栖动物群落的典范对应分析发现叶绿素a、温度、溶解氧和总磷对底栖动物群落有显著影响.本研究表明通过改性当地土壤技术降低水体营养盐含量和叶绿素a含量、增加底泥表层溶解氧含量,可以在一定程度上改善底栖动物生境,提高其物种多样性. 相似文献
10.
为了了解某核电厂周边海域的生态环境状况,筛选潜在威胁核电厂冷源安全的致灾生物,分析影响致灾生物时空分布的主要环境因素,本研究于2018年进行了4个季节的生态调查。结果表明,研究海域浮游植物密度秋季最高,春季优势种为东海原甲藻(Prorocentrumdonghaiense),其他季节优势种为中肋骨条藻(Skeletonema costatum)等硅藻。浮游动物密度夏季最高,以桡足类为主,春、夏季优势种还包括球型侧腕水母(Pleurobrachiaglobosa)和薮枝螅水母(Obeliasp.)。底栖动物的密度和生物量在秋季最高,优势种主要为豆形短眼蟹(Xenophthalmus pinnotheroides)、长吻沙蚕(Glycera chirori)和丝异须虫(Heteromastusfiliforms)。浮游植物、浮游动物和底栖动物群落均在夏季最为稳定,群落多样性水平和物种丰度较高,且分布较为均匀。浮游植物群落的细胞丰度与悬浮物和磷酸盐的浓度正相关性最高。浮游动物的密度受温度和盐度的影响较大。底栖动物的群落分布主要受悬浮物和无机营养盐的浓度影响。本研究共筛选出17种威胁该核电厂冷... 相似文献