Spatial Overlap and Coexistence in a Mussel-Associated Polychaete Assemblage on a South American Rocky Shore     

Mutsunori Tokeshi  & Leonardo Romero 《Marine Ecology》2000,21(3-4):247-261

Abstract. Mussel beds in the intertidal of subtropical South America are known to harbour a large number of invertebrates, particularly polychaetes. This paper presents a quantitative analysis of the patterns of spatial overlap and coexistence in an assemblage of polychaetes associated with mussel beds in a rocky intertidal habitat on the Pacific coast of Peru. Mussel beds are made up of two zones in the intertidal: the lower, more extensive zone formed by Semimytilus algosus and the upper zone formed by Perumytilus purpuratus . Null models were employed to assess the magnitude of spatial overlap between pairs of taxa encompassing a total of seven taxonomic groups. Two taxa belonging to the same functional group tended to be spatially segregated in the Semimytilus bed: Pseudonereis vs. Halosydna (large free-ranging predators) and Scoloplos vs. Mediomastus (deposit feeders), with further segregating tendencies between Pseudonereis and Mediomastus , and between Halosydna and Scoloplos . Small-sized, free-ranging ' Typosyllis ' and the bottom-dwelling scavenging predator Lumbrineris were also spatially associated. Thus, this polychaete assemblage appears to be loosely organised around groupings of taxa which are somewhat different in ecological traits and form mosaic patterns of distribution with reduced overlap within the Semimytilus bed. These relationships were weak to non-existent in the upper, drier Perumytilus habitat where polychaete density was low.  相似文献   

翡翠贻贝肉在冷冻冷藏中质量的变化   总被引：1，自引：0，他引：1  

李庐峰 《台湾海峡》2000,19(3):284-287

本文通过定期测定冷冻冷藏中翡翠贻贝肉的干耗率、过氧化值（ＰＯＶ）、挥发性盐基氮（ＴＶＢ－Ｎ）、ｐＨ值等理化指标,以探索翡翠贻贝肉在冷冻冷藏中质量的变化。结果表明,引起冷冻冷藏中贻贝肉蛋白质的冷冻变化和老化、烹调时口感发渣等的主要原因是水分的干耗和肉的严惩脱水。  相似文献   

黄河三角洲淡水浮游植物名录     

高霞  田家怡 《海洋湖沼通报》2000,(3):65-77

１９９６年对黄河三角洲６条条表性河流和３座代表性水库进行了２－６次浮游值物调查,共鉴定出浮游值物２９１种（变种）,隶属于８门４１科９７属。  相似文献   

Effects of discharge,wind, and tide on sedimentation in a recently restored tidal freshwater wetland          下载免费PDF全文

Eelco Verschelling  Eveline van der Deijl  Marcel van der Perk  Kees Sloff  Hans Middelkoop 《水文研究》2017,31(16):2827-2841

Sediment deposition is one of the key mechanisms to counteract the impact of sea level rise in tidal freshwater wetlands (TFWs). However, information about sediment deposition rates in TFWs is limited, especially for those located in the transition zone between the fluvially dominated and tidally dominated sections of a river delta where sedimentation rates are affected by the combined impact of river discharge, wind, and tides. Using a combined hydrodynamic–morphological model, we examined how hydrometeorological boundary conditions control sedimentation rates and patterns in a TFW located in the Rhine–Meuse estuary in the Netherlands. The modelling results show that net sedimentation rate increases with the magnitude of the river discharge, whereas stronger wind increasingly prevents sedimentation. Sediment trapping efficiency decreases for both increasing river discharge and wind magnitude. The impact of wind storms on the trapping efficiency becomes smaller for higher water discharge. The spatial sedimentation patterns are affected by all controls. Our study illustrates the importance of evaluating both the separate and the joint impact of discharge, wind, and tides when estimating sedimentation rates in a TFW affected by these controls. Such insights are relevant to design measures to reactivate the sedimentation process in these areas.  相似文献   

基于耳石微化学的长江靖江段长颌鲚与短颌鲚生境履历重建   总被引：1，自引：0，他引：1  

陈婷婷  姜涛  卢明杰  刘洪波  杨健 《湖泊科学》2016,28(1):149-155

为了解长江靖江段两种刀鲚生态型长颌鲚与短颌鲚的生境履历的不同,利用X射线电子探针微区分析技术研究采集自长江靖江江段的长颌鲚和短颌鲚个体耳石的锶和钙微化学特征.定量分析结果显示,短颌鲚个体的耳石锶、钙比值(即Sr/Ca×10~3)稳定在2.00左右,反映了其在纯淡水生活的习性;而长颌鲚的锶、钙比值波动显著,不仅具有对应淡水生活的低值(1.18±0.48~2.11±0.94),还具有对应半咸水生活的高值(3.39±0.60~6.79±1.13),反映了其溯河洄游的生活习性.短颌鲚因在淡水生活,其淡水系数(FC)值均为1.00,2013年和2014年长颌鲚的FC值分别为0.36±0.06和0.50±0.11,证明了长颌鲚与短颌鲚群体间存在差异,而且长颌鲚不同年份群体间也并不相同.长颌鲚和短颌鲚的洄游模式存在显著差异,同时不同年份间的长颌鲚也存在生境履历差异.靖江段长颌鲚资源群可能来自不同出生地起源及生活史背景不同的群体.该江段是两类刀鲚的重要栖息地或洄游通道.  相似文献   

应用物种敏感性分布评价中国湖泊水体中重金属污染的生态风险   总被引：7，自引：2，他引：5  

刘昔  王智  王学雷  杨超  宋辛辛  吕晓蓉  李珍 《湖泊科学》2018,30(5):1206-1217

为总体了解我国主要湖泊水体重金属污染现状与生态风险,本文通过历史数据收集,利用物种敏感性分布(SSD)模型与主成分分析法,分析了我国18个湖泊或水域中6种重金属(Zn、Cd、Cr、Cu、Hg和Pb)的分布情况以及其对湖泊淡水生物的潜在生态风险(PAF)和联合生态风险(ms PAF).结果表明:在18湖泊中,6种重金属在湖泊水体中的浓度由高至低依次为Zn(均值为17.06μg/L,范围为4.03~29.33μg/L)、Pb(均值为9.33μg/L,范围为0.04~33.7μg/L)、Cr(均值为5.56μg/L,范围为0.65~40.0μg/L)、Cu(均值为3.71μg/L,范围为0.02~10.2μg/L)、Cd(均值为1.17μg/L,范围为0.01~13.6μg/L)和Hg(均值为0.19μg/L,范围为0.03~1.04μg/L);18个湖泊中重金属的分布情况由3个主成分反映,F1(Cu、Zn、Hg)、F2(Pb、Cd)和F3(Cr、Cu)的贡献率分别为28.50%、24.17%和18.40%,其分布情况受经济和地域差异影响较小;SSD模型显示,不同重金属对全部淡水生物的HC5值不同,从小到大依次为CuCrHgCdPbZn,淡水生物对重金属Cu的敏感性最高,对重金属Zn的敏感性最低;将选取的18个湖泊按ms PAF排序,由高到低依次为呼伦湖(67.0%)鲁湖(56.7%)洱海(52.7%)金银湖(52.3%)太湖(40.5%)墨水湖(39.3%)滆湖(30.2%)鄱阳湖(26.8%)洪泽湖(23.1%)高宝卲伯湖(22.4%)巢湖(20.7%)乌梁素海(19.7%)东湖(19.1%)梁子湖(4.0%)汤逊湖(2.0%)洞庭湖(1%)洪湖(0)=骆马湖(0).研究结果对于了解我国淡水湖泊水质现状和环境安全风险具有重要意义,为湖泊的进一步保护与管理提供了一定的科学依据.  相似文献   

淡水贝类观察——生物阐释水污染和毒理的创新手段   总被引：3，自引：0，他引：3  

陈修报  杨健  刘洪波  姜涛 《湖泊科学》2021,33(1):11-27

淡水渔业是国民经济重要产业,在产量和产值均取得巨大成就的同时,也面临着严峻的水域生态环境污染形势.与此相适应,自2003年系统性提出以背角无齿蚌(Anodonta woodiana)为专用指示生物的创新性“淡水贝类观察”研究体系(Freshwater Mussel Watch)以来,已经成功地应用于国内外的江河、湖泊和池塘等渔业生态环境无机(特别是重金属)和有机污染物胁迫的监测、评价和预警,以及毒理学、污染物积累动力学和水质净化等方面研究.本文梳理了“淡水贝类观察”在被动监测、主动监测及渔业环境研究用模式动物开发等方面的研究进展,以期为渔业以及水域生态环境污染的有效监测、评价、保护以及阐释污染毒性机制提供有益参考.  相似文献   

Palaeoenvironmental history of the Holocene volcanic crater lake Lago d'Averno (central southern Italy) inferred from aquatic mollusc deposits     

F. W. Welter‐Schultes  I. Richling 《第四纪科学杂志》2000,15(8):805-812

The mollusc record from Lago d'Averno, central southern Italy, provides a detailed 1600‐yr record of changes in water quality in response to bradyseismic movements and salinity fluctuations. Bradyseismic vertical land movements and human impact in Roman times led to several transgressions from the Mediterranean Sea, 1 km distant, making the lake a valuable resource for documenting the effect of episodic marine transgressions of a freshwater lake. Low‐oxygen‐tolerant freshwater molluscs suggest that, at around 900–500 bc the lake had a slowly decreasing medium freshwater quality, resulting from contamination of volcanic origin. Disappearance of the obligate freshwater snails and transgression of low‐salinity‐tolerant marine species indicate that, after 500 bc, continuous subsidence resulted in episodic marine transgressions from the nearby sea. The construction of a canal that connected the lake with the sea, in 37 bc, is marked by a considerable increase in the number of shells and by arrival of brackish‐water‐intolerant marine species. Species diversity increased considerably when the area was partly depopulated towards the end of the Roman Empire around ad 400. When the land was slightly uplifted around ad 600–750, the water quality of the lake became less favourable for marine molluscs. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

WIDESPREAD EFFECTS OF CLIMATIC WARMING ON FRESHWATER ECOSYSTEMS IN NORTH AMERICA     

DAVID W. SCHINDLER 《水文研究》1997,11(8):1043-1067

Freshwaters in different regions show many similarities and differences in their responses to climatic warming. Bases for comparison include reports from regional committees, long-term records for several sites where climate has warmed in the past two decades and other human alterations to freshwaters that simulate some of the expected results of climatic warming, such as reservoir construction. Palaeoecological studies of freshwaters under climatic warming and differences in communities under different climatic regimes are also considered. Major changes in the physical, chemical and biological characteristics of lakes occur. Many of the changes to lakes and streams are the result of strong effects of climatic warming on terrestrial catchments. Inputs from catchments can be either dampened or amplified by in-lake processes, in some cases causing counter-intuitive responses, such as the acidification of streams but alkalinization of lakes in areas where supplies of base cations are limited. Consideration of land–water interactions and interactions between climatic warming and other human stresses are important for the accurate prediction of the effects of climatic change. © 1997 John Wiley & Sons, Ltd.  相似文献   

A regional 8200 cal. yr BP cooling event in northwest Europe,induced by final stages of the Laurentide ice-sheet deglaciation?     

Dorthe Klitgaard-Kristensen  Hans Petter Sejrup  Haflidi Haflidason  Sigfus Johnsen  Marco Spurk 《第四纪科学杂志》1998,13(2):165-169

The most notable change in δ¹⁸O in Greenland ice cores during the Holocene occurs at 8200 cal. yr BP. Here we present a new high-resolution marine record from the northern North Sea, along with tree-ring data from Germany, which contain evidence of a pronounced temperature drop (>2°C) contemporaneous with that of the Greenland ice-core records. The synchronous timing of the cooling event in the Greenland ice-cores, marine record and tree-ring data from northwest Europe reflects a regional influence on the North Atlantic ocean–atmospheric system, suggesting a prominent role of the North Atlantic thermohaline circulation. The operation of the North Atlantic ocean circulation is sensitive to variation in the freshwater budget, implying that any change in freshwater flux is capable of altering the North Atlantic circulation system. We hypothesise minor but long-term freshwater fluxes in the final stages of the deglaciation of the Laurentide ice-sheet as a forcing mechanism. © 1998 John Wiley & Sons, Ltd.  相似文献