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1.
On the basis of data collected in the summer of 2006 from 27 sampling stations in the Changjiang Estuary and its adjacent waters, the ecological characteristics of macrobenthos and the relationship between the macrobenthos and the environmental factors were studied using hierarchical cluster and non-metric multidimensional scaling (MDS).The biomass, abundance, Shannon-Wiener's and Margalef's indices of the macrobenthos were presented. The results showed that a total of 253 macrobenthic species were found in the research region, and most of them belong to mollusks and polychaetes. The dominant species were Cossurella dimorpha, Eocylichna cylindrella, Episiphon kiaochowwanense, Nassarius semiplicatus, Ocstergrenia variabilis and Sternaspis scutata. The average abundance of the macrobenthos was (313.15±233.4) ind./m2, and the average biomass was (15.2±11.2)g/m2.The distribution patterns of the abundance and biomass of the macrobenthos were similar. The abundance and biomass in the area close to the estuary were lower than those from the area more distant to the estuary; the central part of the research region had higher abundance and biomass than other parts of the research region. In accordance with the results, four macrobenthic communities with distinct spatial differences were identified. The low abundance and biomass in the area close to the estuary should be caused by the high sedimentation rate. The statistical analysis indicated that the depth is the most important factor affecting the distribution of macrobenthos.  相似文献   

2.
Field investigations of marine macrobenthos were conducted at ten sites in the Bering Sea in July 2010. Altogether 90 species of macrobenthos belonging to 59 families and 78 genera were identified. Among them, 41 polychaetes, 16 mollusks, 23 crustaceans, three echinoderms, two cnidarians, one nemertean, one priapulid, two sipunculids, and one echiuran were identified. The average density and biomass of total macrobenthos were 984 ind./m2 and 1 207.1 g/m2 of wet weight, respectively. The predominant species in the study area were Scoloplos armiger, Eudorella pacifica, Ophiura sarsii, Heteromastus filiformis, Ennucula tenuis, and Harpiniopsis vadiculus by abundance, while the predominant species in this area was Echinarachnius parma by biomass. Hierarchical cluster analysis(Bray–Curtis similarity measure) revealed that two important benthic assemblages in the study area were Community A and Community B. Community A was stable and Community B was unstable, as shown by the Abundance/Biomass Comparisons(ABC) approach. The macrobenthic community structure in the shelf of the Bering Sea was characterized by its high abundance and biomass, high productivity but great heterogeneity.  相似文献   

3.
-The groyne has been used widely in bank protection and river regulation.The plane layoutand structural style of groyne are closely related to the stability of the groyne itself and the effect of bankprotection.In this paper,based on the preliminary summary of the design of bank protection in the boresurging area of Qiantang River,some problems regarding the structure of groyne are pointed out and animproved plan is put forward.Site experiment was carried out combined with an emergency repair.The re-sults of the experiment indicate that the improved project is reliable and successful.  相似文献   

4.
Based on systematized physical, chemical, and biological modules, a multi-species harmful algal bloom （HAB） model coupled with background ecological fields was established. This model schematically embod-ied that HAB causative algal species and the background ecological system, quantified as total biomass, were significantly different in terms of the chemical and biological processes during a HAB while the inter-action between the two was present. The model also included a competition and interaction mechanism between the HAB algal species or populations. The Droop equation was optimized by considering tempera-ture, salinity, and suspended material impact factors in the parameterization of algal growth rate with the nutrient threshold. Two HAB processes in the springs of 2004 and 2005 were simulated using this model. Both simulation results showed consistent trends with corresponding HAB processes observed in the East China Sea, which indicated the rationality of the model. This study made certain progress in modeling HABs, which has great application potential for HAB diagnosis, prediction, and prevention.  相似文献   

5.
Samples were collected with a plankton net in the four seasonal cruises during 2006-2007 to study the seasonal variability of the zooplankton community in the southwest part of Huanghai Sea Cold Water Mass (HSCWM, Yellow Sea Cold Water Mass). The spatial and temporal variations of zooplankton species composition, biomass, abundance and biodiversity were examined. A total of 122 zooplankton species and 30 pelagic larvae were identified in the four cruises. Calanus sinicus and Aidanosagitta crassa were the most dominant species, and Themisto gaudichaudi and Euphausia pacifica were widely distributed in the HSCWM area. The spatial patterns of non-gelatinous zooplankton (removing the high water content groups) were similar to those of the total zooplankton biomass in autumn, but different significantly in the other three seasons. The seasonal means of zooplankton biomass in spring and summer were much higher than that in autumn and winter. The total zooplankton abundance averaged 283.5 ind./m~3 in spring (highest), 192.5 ind./m~3 in summer, 165.5 ind./m~3 in autumn and 65.9 ind./m~3 in winter (lowest), and the non-gelatinous groups contributed the most total abundance. Correlation analysis suggests that the non-gelatinous zooplankton biomass and abundance had a significant positive correlation in the whole year, but the relationship was insignificant between the total zooplankton biomass and abundance in spring and summer. The diversity index H of zooplankton community averaged 1.88 in this study, which was somewhat higher than historical results. Relatively low diversity in summer was related to the high dominance of Calanus sinicus, probably due to the strongest effect of the HSCWM in this season.  相似文献   

6.
Characteristics and evolution of the Kuroshio frontal eddies and warm filaments are analyzed according to two series of satellite images (March 5 to 7, 1986 and April 14 to 16, 1988). The results show that the frontal eddies in the East China Sea are generated at the shelf break and move along the continental slope at a speed of 15 cm/s with the Kuroshio. The frontal eddies occur about every 10 d and evolve to be warm filaments a few hundred km in length and 30-40 km in width in the area west of the Yaku-shima. Meanwhile, the existence of the warm filament was also found in the area by analysing the hydrographic data in the area west of Kyushu during May 24-June 5, 1988.The Kuroshio warm filaments move westward opposite to the Kuroshio and then turn northward at the shelf break and become the main source of the warm water of the Tsushima Warm Current. A simple dynamic explanation for the process is presented in this paper.  相似文献   

7.
Through hydraulic model experiment and site investigation, this paper has derived a calculation formula of dry-laid stone armour layer thickness of rubble mound breakwaters for fishery harbours. The influences of the friction force between stone blocks and the variations of wave length or period and water depth are considered in the formula. The calculated results of several existing structures are in good agreement with field data. This formula is more practical than those ever published both at home and abroad, and has been adoptted by the technical standards of aquatic projects published by the Ministry of Agriculture of China. It is applicable for the calculation of dry-laid stone armour layer of breakwater for small- or medium-size harbours.  相似文献   

8.
Field sampling of the macrobenthos from 23 stations in the Chukchi Sea was conducted during the 4th CHINARE(Chinese National Arctic Research Expeditions, July–August, 2010). We identified a total of 140 species of macrozoobenthos belonging to nine phyla, which were dominated by polychaetes(66), crustaceans(30), and mollusks(25), followed by echinoderms(9) and others(ten others, including four cnidarians, one oligochaete, one sipuncula, one priapulida, two bryozoans, and one urochordata). The dominant species were Aphelochaeta pacifica, Heteromastus filiformis, Nephtys ciliata, Nephtys caeca, Scoletoma fragilis, Golfingia margaritacea, Nuculana pernula, Macoma calcarea, Ennucula tenuis, Macoma inquinata, Musculus discors, Echinarachnius parma, and Ophiura sarsii, so there were more cold-eurythermal boreal immigrants than truly Arctic species(endemics). The average density and biomass(mean ± SD across all stations) of the total macrozoobenthos were(916 ± 907) ind/m2 and(902.9 ± 1 227.7) g/m2(wet weight), respectively. Relatively high density and biomass were observed in the samples from the northeastern and southern Chukchi Sea. The spatial variation of benthic communities in the study sea area was relatively large; this spatial heterogeneity has led to high diversity and a patchy distribution pattern in the community structure. Compared to the 1st CHINARE( July–August, 1999), this investigation revealed different degrees of decreases in the average taxa numbers and the average density, abundance, and biodiversity in the area over the recent decade, which might be associated with global warming, human activities, and sea ice variations.  相似文献   

9.
To explore the spatial pattern of macrobenthic communities and their response to environmental factors in the Prydz Bay,samples were collected using a 0.25-m2 box corer at 10 stations from November 2012 to April 2013.A total of 50 species of macrobenthos belonging to 8 phyla and 33 families were identified,of which polychaetes(e.g.,Maldane sarsi)and sponges(e.g.,Halichondria sp.and Leucosolenia sp.)were the most prominent groups.The macrobenthos in study area were categorized into five functional groups based on the feeding type,and the detritivorous group represented by polychaetes showed the highest average abundance,while the planktophagous group represented by sponges showed the highest average biomass.Macrobenthos abundance(0–592 ind./m2)and biomass(0–1155.5 g/m2)in the Prydz Bay were relatively lower than those of other Antarctic shelf soft-bottom waters,although the compositions of the dominant species and functional feeding groups were similar.The results of the Spearman rank correlation analysis indicated that the average biomass of the macrobenthos and the biomass of the planktophagous group in the study area were negatively correlated with the water depth,sediment grain size and silt percentage.However,these variables were clearly not strong determinants of macrobenthos assemblage structure.Many factors not measured in the study,e.g.,sediment organic matter and iceberg interference,have probably influenced the spatial distribution of macrobenthic community structure in the Prydz Bay.  相似文献   

10.
The studied area is a shallow water area that belongs to the East China Sea continent shelf. The distribution of zooplankton biomass is higher inshore than offshore. The maximum abundance is in the inshore edge of the centre of upwelling, which is the superposed area of the salinity front and temperature front, due to the fact that the mixture of three different waters has brought about a concentration of nutrients. The herbivorous Euphausia, Copepoda and Tunicata are the major groups of the abundant area. Tunicata possess the possibility to compete against other kinds of herbivorous zooplankton. This means that there is negative correlation between the distribution of Tunicata and that of Copepoda and Euphausia. The positions of maximum areas of zooplankton biomass, phytoplankton individual and the concentration of phosphates and chlorophyll-a overlap one another. In the centre of upwelling, zooplankton can not adapt itself to the environment of lower temperature and less oxygen even with rich nutrient  相似文献   

11.
为探究水交换良好海区的滨海核电厂运行对海洋生态环境的长期影响,文章选取秦山核电站为研究对象,利用1989年和1990年、1995年和1996年、2010年和2012年邻近海域叶绿素a、浮游植物、浮游动物、底栖动物调查资料,以及1985年、2010年和2012年潮间带生物调查资料,对比研究发现,邻近海域营养盐增加明显,夏、秋季水温和沉积物有机碳含量略有升高;浮游植物密度增加明显,小型硅藻（具槽帕拉藻和弓束圆筛藻小型变种）占比呈上升趋势;大中型浮游动物春季丰度和生物量下降;大型底栖动物物种数、生物量和栖息密度均升高,钩虾在优势种中占比增加;潮间带生物密度和生物量上升。分析认为,营养盐浓度升高是藻类密度增加的主要诱因;沉积物有机质增加是底栖生物和潮间带生物增加的主要诱因;温排水潜在影响是促进琼氏圆筛藻等暖水种增殖,增加小型硅藻占比,引起浮游动物个体变小,使大中型浮游动物数量下降。由此可见,即使在水交换条件良好的海域,电厂温排水的长期生态影响也应关注。  相似文献   

12.
深沪湾大型底栖动物群落及其次级生产力初步研究   总被引：1，自引：0，他引：1  
2006年1、4月和2008年8月共3个季节在深沪湾潮下带10个取样站定量采集大型底栖动物．根据各个季节获得的大型底栖动物栖息丰度和生物量，采用Brey（1990）的经验公式进行了大型底栖动物次级生产力和P/B值的计算，得出深沪湾潮下带大型底栖动物年平均次级生产力和P／B值分别为0．599g（AFDW）／（m^2·a）和1．561．深沪湾大型底栖动物生物量和平均次级生产力的空间分布为湾顶〉湾中〉湾口．与2000年以来我国近海港湾和河口相关研究结果比较，深沪湾大型底栖动物群落的生态特点是栖息丰度、生物量和次级生产力低，但种类多样性指数较高．这些特征与深沪湾面积小、水动力强和沙质沉积物等环境因素有关．  相似文献   

13.
1995年3～11月对胶州湾北部软底海域进行了 两月一次的大型底栖动物调查。调查期间,大型底栖动物总平均丰度和总平均生物量分别为 1891.3 inds./m2和41.9 g.w.w/m2。与该海域有关大型底栖动物丰度和生物量的历史 资料相比较,本研究所得到的大型底栖动物丰度值显著增加,生物量值则有较明显的下降, 初步分析了发生这些变化主要原因。丰度和生物量比较曲线表明,所研究海域底栖生物群落 处于中等干扰(即污染的影响 )状态。  相似文献   

14.
An ecological optimization project (semi-closed reclamation project) was implemented to control the invasion of Spartina alterniflora, and optimize the habitat of the Chongming Dongtan wetland, in the Changjiang (Yangtze) River Estuary. After project implementation, a macrobenthic ecological survey was conducted in a natural tidal flat and a semi-closed reclamation restoration area within the Chongming Dongtan wetland from 2019 to 2020. Compared with historical data before reclamation, findings showed that the groups, numbers, and species diversity of the macrobenthos increased significantly, and the ecological optimization project resulted in good ecological benefits. In addition, compared to the natural tidal flat, the number of collected macrobenthic phyla, and the macrobenthic density and biomass were significantly lower in the restoration area. Furthermore, the biodiversity index and functional redundancy of natural tidal flats were generally higher, indicating that the community composition and function of natural tidal flats were relatively more stable. Even though the species composition differed between a number of restoration areas and natural tidal flats, there was no difference in functional diversity, indicating that the effect of restoring ecological functions in restoration areas was optimal. Among them, the biodiversity and functional redundancy of Site S2 were significantly reduced, and the ecosystem function was extremely unstable. Habitat heterogeneity, vegetation community and decreasing salinity were the main factors that affected the ecological functions of macrobenthos. The ecological quality was also evaluated; the Transects N3 and N4 showed good quality. The overall ecological quality of the restoration area was generally high, but that of Site S2 was poor and that of Site S2E was merely good, which was mainly due to modifications of the ecological function of macrobenthos. It is suggested that reeds mowing and freshwater species release should be adopted in restoration areas to improve the community function and the environmental disturbance resistance of the macrobenthos.  相似文献   

15.
胶州湾大型底栖动物的丰度、生物量和生产量研究   总被引：3，自引：1，他引：2  
为了研究胶州湾大型底栖动物的丰度、生物量和生产量,于2002年3月、6月、8月和12月,在胶州湾北部软底区、大沽河口、黄岛养殖区及养殖区邻域选取4个站位进行采样,对大型底栖动物进行了定量研究。共采到大型底栖动物138种,总平均丰度、平均生物量(湿质量)和年生产量(有机碳)分别为1 719个/m2,27 g/m2,2.2 g/(m2.a),初步估算,胶州湾大型底栖动物的总次级生产量为2.8万t/a。与渤海和南黄海大型底栖动物的丰度和生物量比较,丰度和生物量均低于这两个海域,但是胶州湾大型底栖动物的总次级生产量高于渤海。本研究对于了解胶州湾大型底栖动物现状及湾内养殖对大型底栖动物的影响具有重要的意义。  相似文献   

16.
基于2018年5月胶州湾海域共计20个站位所获取的生物及环境数据，研究胶州湾大型底栖生物多样性以及群落结构特征。调查海域共发现大型底栖生物208种，大型底栖生物总平均丰度和生物量分别为2 654.38 ind./m2和1 024.512 2 g/m2，大型底栖生物物种数、丰度和生物量均呈现北部高、南部低的分布趋势；调查海域优势种以多毛类为主，IRI值最高的物种为菲律宾蛤仔Ruditapes philippinarum；香农维纳指数与ABC曲线均表明调查海域底栖生态环境整体清洁；在40%相似性水平上，可将调查海域大型底栖生物划分为4个群落；底温和底盐影响调查海域大型底栖生物丰度分布。  相似文献   

17.
Quantitative samples of sediments and macrobenthos were collected with a spade corer to reveal the relationships between macrobenthos communities and bottom environments. Twenty-five stations were established along a transect in the lower sublittoral and bathyal zones between the depths of 120 m and 2,600 m off Sanriku, the northeastern coast of the Japanese mainland, Northwestern Pacific.These stations were clustered into two groups on the basis of the principal component analysis of environmental factors and topographic features of the study area. The clustering of stations corresponded to that based on polychaete species composition.The biomass of macrobenthos followed two different patterns in two oceanographic environments; the first trend is found from the shelf to the seaward margin of the deep-sea terrace where macrobenthos biomass did not depend on depth, and the second trend on the lower continental slope, where biomass decreased exponentially with depth as Rowe's formula predicted. The density of macrobenthos showed a simple exponential decrease with depth over the two ecological zones. The data of stable carbon isotope ratio of organic matter in the sediments and topographic features suggested that the pattern of the biomass of macrobenthos corresponded with two different modes of food supply to the deep-sea bottom communities,i.e., vertical transport of the surface products and horizontal transport of food materials.  相似文献   

18.
2009年4月对舟山海域13个站位的大型底栖生物群落结构的生态特征进行了调查,并结合2001—2008年浙江近岸海域生态环境监测数据资料,分析了该海域大型底栖生物的变化趋势及其生存环境现状。结果表明,调查海域共鉴定出大型底栖生物84种,其中多毛类31种,甲壳类25种,软体动物12种,鱼类8种,腔肠动物4种,棘皮动物和其它类各2种。2009年春季该海域大型底栖生物的生物量平均值为11.62g/m2,丰度平均值为208.5个/m2,生物多样性指数(H′)为1.64,丰度呈由近岸向外海递增的趋势。根据Bray-Curtis相似性系数聚类分析和多维尺度排序分析,该海域大型底栖生物可划分为3个群落,分别为群落Ⅰ:双鳃内卷齿蚕-织纹螺-孔鰕虎鱼群;群落Ⅱ:色斑角吻沙蚕-脊尾白虾群落;群落Ⅲ:葛氏长臂虾-织纹螺群。通过丰度/生物量累积k-优势度曲线分析可知,该海域大型底栖生物群落已受到中度程度的污染或扰动,群落结构不稳定。比较分析2001—2009年舟山海域大型底栖生物生物量和丰度变化趋势可知,个体较小、生长周期较短的种类逐步成为舟山海域的优势类群。  相似文献   

19.
基于2014年秋季（11月）在黄海海域所获取的大型底栖动物及环境数据,研究了黄海海域大型底栖甲壳类动物的种类组成、丰度、生物量、多样性以及群落结构特征等。调查海域共发现71种大型底栖甲壳类动物,隶属于32科45属,其平均丰度和生物量分别为278inds./m2和2.33g/m2。IRI值最高的物种为太平洋方甲涟虫Eudorella pacifica。在23%的相似度水平上,可以将大型底栖甲壳类划分为六个群落。Pearson相关性结果显示,太平洋方甲涟虫Eudorella pacifica丰度与水深呈极显著正相关,与底盐呈显著正相关,与底温呈显著负相关。大型底栖甲壳类动物的物种数占比在黄海大型底栖动物类群组成中变化不大,都在30%左右。BOPA指数表明,调查海域底栖生态环境整体良好,仅黄海中部和南部部分站位可能存在中度扰动;BOPA指数能较好地评价研究海域的环境质量状况。  相似文献   

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