首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
大型底栖动物是河流生态系统中重要的生态类群,研究其群落组成及分布特征能为河流生态系统管理提供理论支撑。2018年6月(夏季)和11月(秋季),在崇明岛内河设置16个固定站点,开展了拖网和地笼相结合的大型底栖动物调查,分析研究了崇明岛内河大型底栖动物群落的组成与分布特征及影响因子。调查期间共采集到大型底栖动物14种,分属5目8科,主要为节肢动物。其中,淡水型10种,河口半咸水型3种,降海洄游型1种。从空间分布来看,北横引河记录12种,南横引河记录6种,竖河记录11种;不同河道大型底栖动物群落组成均以淡水型种类为主,主要优势物种为日本沼虾(Macrobrachium nipponense)和秀丽白虾(Exopalaemon modestus);北横引河大型底栖动物群落的物种数、多度及生物量均高于南横引河;而竖河介于两者之间。夏季大型底栖动物群落的物种数、多度和生物量均高于秋季,季节变化是崇明岛内河大型底栖动物群落组成变化的重要特征之一。综合来看,崇明岛内河大型底栖动物群落组成特征兼具内陆河流和河口区特点,它与崇明岛区位特征、河流水文及生境条件、水质特征及区域人类活动等多种因素有关。  相似文献   

2.
Waste disposal in the apex of the New York Bight has resulted in the contamination of sediments by toxic chemicals and some alteration to the community composition of the benthic macrofauna. The significance of these alterations to other communities in the area, e.g. its fishery resources, has not been clearly demonstrated. This paper presents data on an extensive survey of the macrofauna biomass, that many fish and lobster feed on, in the waste disposal impacted areas of the apex, using samples from both 1973 and 1980–1982. Variable mean production to biomass (P:B) ratios were used to estimate secondary production from the biomass of each major taxon. The macrofaunal biomass (wet wt.) of most of the apex area impacted by waste disposal was relatively high, with a mean biomass of 127 g m?2 for 1973 and 344 g m?2 for 1980–1982. Estimated secondary production was also high, being 201 Kcal m?2 year?1 in 1973 and 383 Kcal m?2 year?1 in 1980–1982. These values suggest there has been no inhibition of at least biomass, as the values were similar to or greater than values found in other areas of the Bight with similar bathymetric characteristics.  相似文献   

3.
The northern New England beach wrack community with special reference to the cosmopolitan amphipod crustacean, Orchestia platensis, was examined at estuarine and open coastal habitats. Beach wrack was dominated by the plant genera Ascophyllum, Zostera, Spartina and Chondrus, and was most abundant during spring and late summer. Animal community numbers, biomass and frequency in fresh to moderately decomposed wrack were dominated by O. platensis throughout the year at all habitats; oligochaetes and Collembola were also important. The abundance of O. platensis showed high spatial and temporal variability, with low abundance generally associated with decreased amounts of wrack during colder months. An exception was the winter presence of the species at one estuarine habitat, in patchy aggregations within gravel-cobble refuges. The abundance of O. platensis averaged 1280 (0.04 m2)−1, with a maximum of 7040 (0.04 m2)−1. The life cycle of O. platensis is bivoltine, with summer-hatched young reaching maturity within 1 month. Laboratory studies indicate females with up to 4 broods (30 days)−1, averaging 18 eggs brood−1.Orchestia platensis is omnivorous, eating fresh plant tissue, live oligochaetes, Limulus eggs and diatom ‘fuzz’. The rate of laboratory consumption of algae and Zostera was 0.05 mg plant mg−1 wet body weight day−1. Presumptive predators of O. platensis are juvenile green crab, Carcinus maenus, and the earwig. Anisolabis maritima. The mobility, aggregation and aggressiveness of O. platensis assist the species in establishing and maintaining populations in the rigorous wrack habitat. The general competitive superiority of O. platensis over its congener, O. gammarella, and the co-occurrence of these species on both eastern and western Atlantic shores is discussed.  相似文献   

4.
The soft-bottom fauna of Gunnamatta Bay, Port Hacking, N.S.W., was sampled to estimate the abundance, trophic structure and net production of the macrobenthos. The samples were classified into groups from spatially distinct strata, the groups differing in species abundance and diversity and in the identity of the dominant species. The composition and community structure of the fauna was generally similar to that in other sheltered embayments on the southeastern coast of Australia. Estimated production values were low for an estuary, ranging from 10 kJ m?2 year?1 in an intertidal stratum of well sorted sand to 210–450 kJ m?2 year?1 in shallow subtidal strata with an admixture of silt. Estimated net production over all strata was 160 kJ m?2 year?1. Polychaetes dominated production, providing 45% of the total; crustaceans provided 20%, and molluscs and echinoderms 12% each. Detritus-feeders were dominant in most strata: the bivalve Theora fragilis, the polychaetes Australonereis ehlersi and Notomastus torquatus, and the urchin Echinocardium cordatum were major contributors to overall biomass and to net production. Substantial biomass and net production was also contributed by the suspension-feeding bivalve Corbula vicaria and a carnivorous crab Ceratoplax cf. glaberrimus. Overall, detritus-feeders contributed 61% of estimated net production, carnivores 32% and suspension-feeders 7%. Production estimated for carnivores was higher than could be supported by the non-carnivore populations, suggesting that some of the species considered to be carnivores have additional feeding modes. Excessive harvesting of bivalves by humans is suggested as the main reason for the low biomass of, and therefore low production by, suspension feeders.  相似文献   

5.
6.
The behavior of dissolved and particulate iron and manganese and dissolved silicon has been studied as a function of chlorinity in the Peconic River estuary, New York. This study sought to identify important geochemical processes in a relatively pristine estuary facing increasing anthropogenic impact.Dissolved iron behaved in the classical non-conservative manner exhibiting removal of nearly 80% at very low chlorinities, while particulate iron increased by a corresponding amount over the same chlorinity range. Dissolved manganese was enriched by up to 200% over its predicted concentration at low and intermediate chlorinities by desorption from suspended particulates and by a probable benthic flux. Dissolved silicon was enriched by up to 100% at low and intermediate chlorinities also from a probable benthic flux. These fluxes were estimated to be 5 μg cm?2 day?1 for dissolved manganese and 70 μg cm?2 day?1 for dissolved silicon.The quantity of both particulate iron and manganese increased at high chlorinities due to an influx of suspended inorganic particulates. In the intermediate to high chlorinity region, oxidation of sediment-derived manganese is believed to contribute to the observed increase in particulate manganese.Total iron was essentially conservative throughout most of the estuary, while total manganese was non-conservative presumably due to extensive remobilization of dissolved manganese from the sediments.  相似文献   

7.
珊瑚礁是全球生物多样性最高的海洋生态系统之一,底栖贝类是该生态系统的重要组成类群。为了解北部湾涠洲岛珊瑚礁底栖贝类的群落现状及特征,于2015年秋季(10月)与2018年春季(5月)采用水肺潜水截线样条定量调查法对涠洲岛珊瑚礁区6个断面的底栖贝类进行了调查,并分析了物种组成、丰度、生物多样性指数等群落特征。综合两次调查结果显示涠洲岛珊瑚礁区共有底栖贝类128种,分别属于多板纲1科1属3种,腹足纲25科46属68种,双壳纲22科31属57种。优势种为斑顶拟舌骨牡蛎、粗衣蛤、刺荔枝螺、马蹄螺、杂色牙螺、青蚶、旗江珧、甲虫螺、蕾丝蟹守螺、珠母爱尔螺。2018年春季定量断面采集到的样品为2纲14科43种,各断面的丰度、生物量、多样性指数、物种丰度指数和均匀度指数均值分别为3.39个/m2、86.94 g/m2、3.31、3.50、0.37。通过对两年的调查数据比较,发现2015-2018年涠洲岛珊瑚礁区的贝类生物群落呈现良好演替发育趋势。南海珊瑚礁区贝类群落结构可能受到了人为干扰强度和纬度的双重影响。本研究全面掌握了涠洲岛珊瑚礁底栖贝类的种类、分布区及群落的结构与变化,可为该地区海洋生物资源开...  相似文献   

8.
An assessment of community composition and the functional roles of the dominant species has been carried out in two intertidal areas of Malaysian mudflat dominated by natural populations of the arcid bivalve mollusc Anadara granosa.In addition to A. granosa, organisms of numerical importance are the venerid bivalve Pelecyora trigona, the neogastropod Plicarcularia leptospira, the mesogastropods Stenothyra glabrata and Cerithidea cingulata and the hermit crab Diogenes sp. The mesogastropod Natica maculosa and the neogastropod Thais carinifera may be of some importance to community organization but they are not numerically dominant. Annelids are conspicuous by their absence.The following trophic roles are ascribed to specific members of the community: A. granosa—facultative surface deposit feeder; P. trigona—suspension feeder; P. leptospira—scavenger; C. cingulata—deposit feeder/grazer; S. glabrata—deposit feeder/grazer; N. maculosa—predator; T. carinifera—predator; Diogenes sp.—scavenger/predator. S. glabrata is of particular interest because it appears to fill the niche occupied by mud snails of the genus Hydrobia in temperate mudflat systems.There is evidence of seasonality on the mudflats which points to a spawning of certain forms triggered by the major annual salinity depression at the time of the onset of the north-east monsoon in October/November. Concentrations of benthic chlorophyll a show no obvious signs of a seasonal fluctuation and the seasonality of the primary consumers is not thought to be related to food abundance. However there is some evidence of seasonality of reproduction in N. maculosa which preys on the seasonally reproducing bivalves.  相似文献   

9.
泉州湾北岸潮间带大型底栖生物群落研究   总被引:1,自引:0,他引:1       下载免费PDF全文
2014年9月和2015年5月,分别在泉州湾北岸布设3条潮间带断面进行大型底栖生物群落研究.共计采获潮间带大型底栖生物样品166种,其中泥沙滩有80种,岩相有96种.其中环节动物、软体动物和节肢动物有145种,构成该区域潮间带大型底栖生物的主要类群,调查的3条断面中,泥沙滩断面的平均栖息密度和生物量分别为133 ind./m~2和24.48 g/m~2,岩相断面的平均栖息密度和生物量分别为1 412 ind./m~2和958.78 g/m~2.数量垂直分布,泥沙滩断面和岩相断面平均栖息密度和生物量均以中潮区低潮区高潮区.数量季节变化,泥沙滩断面平均栖息密度和生物量均为春季(170 ind./m~2和32.04 g/m~2)大于秋季(96 ind./m~2和16.92g/m~2),岩相断面平均栖息密度为春季(1 360 ind./m~2)小于秋季(1 464 ind./m~2),而平均生物量为春季(1 122.83 g/m~2)大于秋季(794.75 g/m~2),数量季节变化显著.丰度/生物量曲线显示,泉州湾北岸潮间带大型底栖生物群落群落结构较为稳定,受到干扰较小.  相似文献   

10.
The vertical distributions of excess 210Pb and fall out 239, 240Pu imply a uniform sedimentation rate of 1·4–1·6 cm year?1 from 0 to 105–110 cm. This sediment accumulation rate is compatible with sulfate reduction rate data from this location. Below 70 cm only ‘aged’ refractory carbon is present (CR = 1·8% C) with an age of approximately 2400 years. This phase is present in a number of locations across Long Island Sound. Planktonic carbon (CP) is present above the 60–67 cm horizon. A value of 1·0 for AP (14C activity) at 32–37 cm was taken, AP = 1·285 was used for contemporary plankton. This was obtained by correcting the measured AP of a plankton tow sample for admixed refractory carbon. These values were then used to calculate CR, CP and CF (fossil carbon) at 32–37 cm and 6–12 cm. The only values compatible with the known sulfate reduction rate data are CR equal to pre 60–67 cm levels (1·6–1·8% C), CF being 0·3% C at both depths, and CP decreasing with depth from 0·3 to 0·4% C at 6–12 cm to close to zero at 32–37 cm.  相似文献   

11.
蓝文陆  黄凌风  郭丰  潘科 《海洋学报》2005,27(6):131-137
2001年8月至2002年7月,对厦门岛东海岸黄厝沙滩底栖甲藻的种类组成和优势种的时空分布进行了为每月一次的调查,共鉴定甲藻种类46种,其中底栖种39种,常见种14种,优势种4种.Amphidinium britannicum和Adenoides sp.为冬春季优势种,Herdmania litoraris和Peri-dinium quinquecorne为夏秋优势种,优势种的季节更替比较明显.夏秋季节的种数多,冬春季节的种数少,细胞数量高峰出现在春夏季,秋冬两季数量很少,由夏季的200多个每克干沙减少到冬末的0~4个/g干沙;多样性指数和均匀度呈双峰型分布,峰值出现在10和2月,谷值出现在12月和7月.空间分布上,底栖甲藻的总细胞密度和优势种的细胞密度呈现由高潮带向中、低潮带增加的趋势.分析了影响厦门东海岸沙滩底栖甲藻时空分布的主要因素,并探讨了沙滩底栖甲藻与近岸赤潮及着色砂现象的关系.  相似文献   

12.
海坛岛潮间带底栖生态的初步调查   总被引:1,自引:0,他引:1  
陈昌生 《台湾海峡》1992,11(4):294-300
本文报道了1984年10~11月和1985年4~5月对海坛岛4种潮间带底栖生态的初步调查。结果表明,该区底栖生物经鉴定的种类280种,以暖水性种类占多数,且有些已成为优势种或主要种;不同岸相潮间带底栖生物种类数多寡顺序是岩石滩>泥滩>沙泥滩>沙滩;平均最大生物量(634.26g/m~2)和平均最高栖息密度(508.55个/m~2)分布在岩石滩,其次是泥滩。文中还对各滩的开发利用提出了建议。  相似文献   

13.
2006年1月~10月福建闽东大嵛山附近海域游泳动物调查研究结果表明,该海域的游泳动物有97种,其中鱼类51种(软骨鱼1种,硬骨鱼类50种),隶属于9目24科42属;甲壳类42种,隶属于2目15科20属;头足类4种,隶属于3目3科3属.暖水性种类为33种,占鱼类总种数的64.7%;暖温性鱼类18种,占鱼类总种数的35.3%,未出现冷温性和冷水性鱼类.种类数的季节变化依次呈夏季〉冬季〉秋季〉春季.生物量的季节变化,依次呈夏季〉秋季〉春季〉冬季;而生物量尾数的季节变化,依次呈夏季〉春季〉秋季〉冬季.平均单位网次渔获生物量和密度分别为9.53kg/h和1 319 ind/h.生物量优势种和密度优势种分别为大黄鱼和中华管鞭虾.扫海面积法估算年平均现存资源量为57 370 ind/km^2和404.51kg/km^2.同时,本文对该海域游泳生物的资源结构现状与历史调查数据作了对比分析,并讨论了多样性结构与生物量的季节性变化规律.结果表明,该海域渔业资源有严重衰退的现象,多样性结构与生物量的季节性变化并不具有必然的一致性.  相似文献   

14.
大型底栖动物是盐沼湿地中最重要的生物类群之一。本文以长江口九段沙湿地为研究区域,于2016年10月在江亚南沙、上沙和下沙的不同区域沿高程梯度设置固定采样站点,对大型底栖动物、沉积物和植物进行取样调研,分析研究了大型底栖动物的分布特征及其影响因子。结果表明:(1)大型底栖动物沿高程梯度的分布具有一定规律性:低潮带环节动物的多度和生物量均最高,中潮带软体动物的物种数最多,高潮带甲壳动物的多度和生物量均最高;(2)不同区域由于环境条件的差异,大型底栖动物沿高程梯度的分布特征也有明显差异;(3)对大型底栖动物分布特征有显著影响的生境因子主要包括沉积物中值粒径、氧化还原电位和植株密度等,不同区域、不同生境中对大型底栖动物的分布特征有显著影响的生境因子也有一定差异;(4)互花米草(Spartina alterniflora)的入侵改变了生境条件,进而对大型底栖动物的分布特征产生影响。在今后的研究中,要充分考虑不同区域、不同高程之间环境条件的差异,进一步探讨盐沼湿地大型底栖动物的分布特征及影响因子的综合作用。  相似文献   

15.
确定自然海岸特征是海岸修复中的重要内容,但是在开发后弃管的无居民海岛却面临缺少历史资料参考的困难。在大连普兰店湾中部前大连岛的研究证明,依据历史影像和现存海岸地质地貌情况可以分析确定原自然海岸位置及性质。1972年KH 卫星影像表明当时的前大连岛仍然保持自然海岸形态,海岸位置在2020年海岸后 方的岛屿陆域内部。结合2020年海岸地质考察结果可以进一步确定1972年的前大连岛东部、西部分布海蚀崖形式的基岩海岸,南部、北部则分布砾石质海岸。1972—2020年,前大连岛自然海岸全部变化为人工海岸,海岸长度也从约2.38 km 增加至约3.12 km。  相似文献   

16.
福建海岛潮间带底栖生物群落生态的研究   总被引:11,自引:0,他引:11  
对福建海岛潮间带大型底栖生物共鉴定862种,其中动物为734种,藻类为128种。对11个主要海鸟的潮间带生物群落测定Jaccard群落系数,应用加权均值联结法聚类分析及极坐标排序分析,海岛潮间带生物群落可分为3个类型:(1)开敞海域群落,宏观上分布于地处远岸水域的海岛或近岸凸出部、开阔部水域的海岛;(2)近岸港湾群落,分布于近岸或港湾的海岛;(3)河口群落,分布于河口区的海岛。群落种类组成和海岛所在地理集团及其生境密切相关。盐度水扰动程度是影响群落分 布的主要因子。  相似文献   

17.
18.
Abundance and species composition of aquatic benthic macroinvertebrates were compared between an area sprayed with the herbicide Grazon (active ingredient triclopyr), and an upstream control site (no triclopyr). Five Surber samples were collected from each of three riffles in control and treatment sites on eight occasions over a 1‐month period. Aquatic invertebrate species composition was similar in treatment and control sites, and did not change over time. The five taxa that made up 91–95% of all invertebrates by abundance did not vary significantly in treatment compared to control riffles. Abundance of three of the 15 most common taxa (>10 individuals per riffle) differed significantly between treatment and control sites over time. However, none of these fluctuations correspond to the presence of known concentrations of triclopyr in water samples, and it is unlikely that the declines resulted from triclopyr. These results are discussed with reference to known lethal concentrations of triclopyr for some invertebrates, and to the effect of floods on invertebrate populations.  相似文献   

19.
黄海夏季典型站位的底边界层动物   总被引:1,自引:0,他引:1  
2002年8月25~26日,在黄海夏季冷水团区域内的抛锚站位(35°22′N,121°59′E),使用柱状界面采样器进行了昼夜连续取样,对底边界层动物的种类组成与昼夜丰度变化进行了研究,以获得对黄海底边界层动物的初步认识。共记录底边界层动物21种,隶属18科、19属。超底栖动物和中型浮游动物是黄海夏季底边界层动物的2个重要类群,主要种类有尖额真猛水蚤(Euterpina acutifrons)、挪威小毛猛水蚤(Microsetella norvegica)、异厚盖钩虾(Synchelidium miraculum)、双刺纺缍水蚤(Acartia bifilosa)和小拟哲水蚤(Paracalanus parvus),其丰度皆有明显的昼夜波动现象。以桡足类无节幼体为代表的小型浮游动物也是底边界层动物中不容忽视的类群之一。采集到5个黄海区的新记录物种:美丽猛水蚤(Nitocrasp.)、跛足猛水蚤(Mesochrasp.)、咸水剑水蚤(Halicyclopssp.)、掌刺梭剑水蚤(Lubbockia squillimana)和异厚盖钩虾(Synchelidi-um miraculum),显示出底边界层动物种类组成的特殊性。  相似文献   

20.
于2007年4月对山东南部近海进行了32个站位的大型底栖动物研究,共发现大型底栖动物170种,其中多毛类87种,软体动物25种,甲壳类47种,棘皮动物7种,其他类群4种。排名前3位的优势种是背蚓虫(Notomastus latericeus)、东方缝栖蛤(Hiatella orientalia)和寡鳃齿吻沙蚕(Nephtys oligobranchia)。研究海域大型底栖动物总平均丰度为1494 ind/m~2,总平均生物量为13.88 g/m~2,生物多样性指数H′、J′和d的平均值分别为:3.856、0.805和4.004。在30%相似度水平上,该海域大型底栖动物可划分为4个群落。综合H′和ABC曲线的结果,山东南部海域底栖生态环境较好。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号