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1.
Habitat utilization by fishes in a shallow, semi-enclosed estuarine bay in southern Gulf of Thailand
Sukree Hajisamae Pun Yeesin Saweit Chaimongkol 《Estuarine, Coastal and Shelf Science》2006,68(3-4):647
One hundred and eight fish species were collected between March 2003 and February 2004 from 11 study sites in Pattani Bay, southern Gulf of Thailand. The catches consisted primarily of juveniles or adults of small-sized fishes, indicating that the bay was important as nursery ground for fishes. Of the 43 families, Leiognathidae (43.3% contribution), Centropomidae (15.2%), Siganidae (13.8%), Engraulidae (10.3%), Atheriniidae (6.9%), Clupeidae (4.8%) and Ariidae (3.1%) were dominant in the catch. Significant differences were found in relative abundance and species richness between both sampling sites and months. The sampling sites were clearly defined by fish community into four different habitats that were directly related with the bottom structure of each site. The 30 most dominant fish species were categorized according to habitat preference into five different groups. Some species exhibited preference for specific habitats, whereas others were distributed throughout the bay. Seasonally, fish community structure revealed four different recruitment and occurrence periods, which were February to April, May to September, October and November to January, which was partially related to local monsoonal seasons. Analysis of the 30 most dominant fish species demonstrated that they were clustered into six different seasonal groups, with some showing a clear preference for specific months, although many recruited and occurred throughout the year. Results of this study help to clarify the ranges of habitats, months and seasons used by a number of fish species found in tropical coastal habitat. 相似文献
2.
杭州湾北岸潮间带生态学研究——Ⅰ.软相底栖动物群落调查 总被引：6，自引：0，他引：6
地处陆、海交界的潮间带,底栖生物与栖息环境密切相关,环境一旦受污染,生物群落结构将发生变化,影响到生态平衡。位于杭州湾北岸中部的上海石油化工总厂,投产后对该湾环境质量是否有潜在污染的可能性,将是个重大问题。为了比较本厂投产后对本区域生态学的影响,在上海市环境保护局领导下,上海石油化工总厂、上海市卫生防疫站、国家水产总局东海水产研究所和国家海洋局第三海洋研究所等单位相互协作,自1975年5月开始在该湾软相潮间带设五个断面,逐年定期地开展调查。 相似文献
3.
Long-term effects of a toxic algal bloom on subtidal soft-sediment macroinvertebrate communities in Wellington Harbour, New Zealand 总被引：3，自引：1，他引：2
Kerstin Krger Jonathan P.A. Gardner Ashley A. Rowden Robert G. Wear 《Estuarine, Coastal and Shelf Science》2006,67(4):589-604
The long-term effects (>1 year) of a naturally occurring toxic plankton bloom (Karenia brevisulcata) on subtidal benthic macroinvertebrate communities were investigated in Wellington Harbour, a semi-enclosed temperate embayment in New Zealand. For 3 years communities were sampled at three different sites in the harbour. Analyses revealed that community recovery following the bloom was site-specific. Multivariate analyses indicated that at one site community composition was approaching recovery 3 years post-bloom. At the second site, a sequential recovery process was indicated, whereas at the third site the community composition oscillated from year to year, but did not show any signs of a sequential recovery process. The nature of the hydrodynamic regime was identified as a major factor influencing the observed recovery processes. Communities exposed to an active hydrodynamic regime were less affected by the bloom and differed little in their composition pre- and post-bloom, as they were naturally in a perpetual state of recovery as indicated by a dominance of r-selected species. The community at the hydrodynamically less active site was more affected by the bloom and exhibited temporal differences in composition consistent with successional models. Complete recovery to a pre-disturbance climax community dominated by K-selected species is likely to take 4–5 years, if not interrupted by other disturbances. Given the increased occurrence of harmful algal blooms worldwide, more monitoring and manipulative studies are needed to further evaluate the effects of such disturbances on macrobenthic communities. 相似文献
4.
自1998年“捕捞降低海洋食物网”概念首次提出以来,渔获物平均营养级（Mean trophic level of fisheries landings,MTL）广泛用于评估捕捞活动对生态系统完整性的影响,并指导管理机构的政策制定。近年来研究表明,掌握MTL的潜在变化机制对于以MTL作为渔业可持续性指标至关重要。根据联合国粮农组织FAO提供的渔获统计数据,结合Fishbase提供的相关鱼种营养级,本文探讨了全球三大洋14个FAO渔区MTL的变化趋势,并进一步分析不同MTL变化趋势下高营养级鱼种和低营养级鱼种渔获量的变动情况。研究表明, MTL呈上升和回升状态均可能伴随着低营养级鱼种渔获量的下降。此外,通过观察营养级高于3.25鱼种的MTL以区分“捕捞降低海洋食物网”和“捕捞沿着海洋食物网”现象需考虑生态系统的群落结构和开发历程。利用渔获物平均营养级评价渔业可持续性必须综合考虑高营养级和低营养级鱼种,以及群落结构和开发历程的掩盖效应。 相似文献
5.
Zhimeng Xu Xue Song Min Wang Qian Liu Yong Jiang Hongbing Shao Hongbin Liu Kunpeng Shi Yang Yu 《Journal of Oceanography》2017,73(5):687-699
Picoeukaryotes are important members of the surface ocean microbial community with high diversity and significant temporal and spatial variations in community composition. Little is known about the picoeukaryotic biodiversity and community in the Yellow Sea, where hydrologic conditions are very different with the influence of the Yellow Sea Warm Current (YSWC). Using Illumina high throughput sequencing targeting 18S rDNA, we investigated the composition of picoeukaryotes at a permanent monitoring site in the central Yellow Sea from 2011 to 2013. Alveolata, Stramenopiles, and Archaeplastida were the main super groups found. Prasinophytes were dominant in N-YSWC (not influenced by the YSWC) samples whilst YSWC (influenced by the YSWC) samples were dominated by different groups, such as MALV-II (novel marine Alveolata), MAST-3, MAST-4 (novel marine Stramenopiles), and Dictyochophyceae. N-YSWC samples were grouped together in nMDS (non-metric multidimensional scaling) using the Bray–Curtis method. Distances between each two YSWC samples were greater. Based on indicator operational taxonomic unit (OTU) analysis (IOA), indicator species of the YSWC were represented by Pseudochattonella farcimen, Florenciella parvula within the class Dictyochophyceae, and Phaeocystis cordata within the class Prymnesiophyceae. The findings in our study suggest that picoeukaryotic communities in the central Yellow Sea differ temporally in response to changes in the YSWC. 相似文献
6.
An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor analysis(PARAFAC) and CHEMTAX. The PARAFAC model was applied to fluorescence excitation-emission matrix(EEM) of 60 algae species belonging to five divisions and 11 fluorescent components were identified according to the residual sum of squares and specificity of the composition profiles of fluorescent. By the 11 fluorescent components, the algae species at different growth stages were classified correctly at the division level using Bayesian discriminant analysis(BDA). Then the reference fluorescent component ratio matrix was constructed for CHEMTAX, and the EEM–PARAFAC–CHEMTAX method was developed to differentiate algae taxonomic groups. The correct discrimination ratios(CDRs) when the fluorometric method was used for single-species samples were 100% at the division level, except for Bacillariophyta with a CDR of 95.6%. The CDRs for the mixtures were above 94.0% for the dominant algae species and above 87.0% for the subdominant algae species. However, the CDRs of the subdominant algae species were too low to be unreliable when the relative abundance estimated was less than 15.0%. The fluorometric method was tested using the samples from the Jiaozhou Bay and the mesocosm experiments in the Xiaomai Island Bay in August 2007. The discrimination results of the dominant algae groups agreed with microscopy cell counts, as well as the subdominant algae groups of which the estimated relative abundance was above 15.0%. This technique would be of great aid when low-cost and rapid analysis is needed for samples in a large batch. The fluorometric technique has the ability to correctly identify dominant species with proper abundance both in vivo and in situ. 相似文献
7.
为了解西沙群岛珊瑚礁海域浮游动物的群落特征, 于2015年5月末至7月初在西沙群岛8个岛礁(七连屿、永兴岛和东岛3个岛屿以及浪花礁、盘石屿、玉琢礁、华光礁和北礁5个环礁)进行了浮游动物采样, 分析了浮游动物的多样性、丰度和群落结构特征, 并比较了5个环礁潟湖内和向海礁坡区浮游动物群落组成的差异。调查海域共鉴定浮游动物180种(包括浮游幼虫13个类群), 其中桡足类最多, 达83种, 其次是水母类(38种)、浮游软体类(14种)、毛颚类(11种)和浮游被囊类(7种); 浮游动物平均丰度为256.4±117.8个·m-3, 桡足类占总丰度的51.08%, 其次是浮游幼虫(16.30%)、浮游被囊类(13.22%)和毛颚类(7.70%)。浮游动物种数、多样性和均匀度指数、丰度在岛屿和环礁之间以及环礁的潟湖区和向海礁坡区均存在差异; 浮游动物多样性和丰度在东岛、玉琢礁和华光礁较高, 而在七连屿和北礁较低; 5个环礁向海礁坡区的浮游动物多样性和丰度皆高于潟湖区的。多元统计分析结果表明调查岛礁的浮游动物可划分两个聚群(相似水平85%); 岛屿近岸及环礁的潟湖群落(Ⅰ)和岛屿远岸及环礁的向海礁坡群落(Ⅱ); 两个聚群浮游动物组成差异较显著(r=0.832, p<0.001); 前者的种数、多样性指数、总丰度和主要浮游动物类群如桡足类、毛颚类和浮游幼虫的丰度显著低于后者。环礁潟湖区和向海礁坡区的空间异质性和生态环境差异可能是导致浮游动物群落结构呈现不同特征的主要因素。 相似文献
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9.
Responses of a Mediterranean soft bottom community to short-term (1993-1996) hydrological changes in the Rhone river 总被引：1，自引：0，他引：1
The polychaete fauna of muddy bottoms off the Rhone delta (NW Mediterranean) was seasonally sampled at two sites at 70 m depth, from 1993 to 1996. During this period, five severe flood events occurred. A clustering analysis (distance coefficient of Whittaker) and three way fixed factor ANOVAs (site x season x year) showed strong year-to-year changes in species density and community structure, changes that masked seasonal variations. Total density increased by a factor of 3 and density of most species significantly increased following the first flooding event. Changes in the community structure were due to the successive dominance of a few species. The opportunistic species, such as Cossura sp., Mediomastus sp. and Polycirrus sp., exhibited peaks in density 1-3 months after the flood. These peaks were followed by a drastic decline. For species with a long life span, such as Sternaspis scutata, a slower but continuous increase in density was observed which was maintained for several months. The density fluctuations of these species exhibited a good correlation with river flow with time lags of 1-2 years. The successional dynamics observed are explained according to the geographical origin of the floods and the biology and feeding ecology of species. 相似文献
10.
本研究通过构建16S r DNA克隆文库,对东海陆架五个站点的沉积物样品进行群落结构及地理分布研究。结果表明:东海陆架沉积物细菌分属于13个类群,包括变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)、酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)、放线菌门(Actinobacteria)、硝化螺旋菌门(Nitrospira)、WS3、拟杆菌门(Bacteroidetes)、螺旋体门(Spirochaetes)、OP8、浮霉菌门(Planctomycetacia)、疣微菌门(Verrucomicrobiae)和芽单胞菌门(Gemmatimonadetes),其中变形菌门(γ-变形菌纲、δ-变形菌纲)和绿弯菌门为优势菌群,Latescibacteria(WS3)、疣微菌门和芽单胞菌门分别是站点DH6、DH21和DH9的特有类群。五个站点细菌多样性从高到低排序依次为DH9DH21DH17DH6DH16,其群落结构和丰度与各站点不同沉积环境类型有关。 相似文献
11.
Dietary analysis of harbour seals (Phoca vitulina) from faecal samples and overlap with fisheries in Erimo,Japan 
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下载免费PDF全文 Tabitha C. Y. Hui Yuka Morita Yumi Kobayashi Yoko Mitani Kazushi Miyashita 《Marine Ecology》2017,38(3)
The number of harbour seals in Japan has been rebounding since protection began in the mid‐1980s. With the increase in seal numbers, increased conflict with fisheries has occurred through depredation and the belief that seals compete with fisheries for prey. However, competition can only be determined if the prey species and quantities seals consume over time are known. We studied the diet of harbour seals in Erimo, site of the largest population of harbour seals in Japan, from 2011 to 2012 and assessed the degree of prey overlap with local fisheries. We used both hard parts and DNA techniques to identify prey items in seal scats, and compared these results to local fisheries data. A total of 46 prey occurrences was detected by both methods, of which 17 matched between techniques at least to the family level. Hard parts methods identified five incidences of prey undetected by DNA methods in five scats (one incidence per scat). DNA methods identified 24 additional prey occurrences in 13 scats, for which no hard part evidence for that prey had been found. This more than doubled the total number of prey occurrences across the 15 scats compared. Overall, the most frequently occurring harbour seal prey were walleye pollock (Theragra chalcogramma), sculpins and snailfishes. In contrast, the top three groups targeted by fisheries were codfishes, salmon and invertebrates. Many species common in the harbour seal's diet such as snailfishes and blennies were not targeted by fisheries. Fishes such as greenlings, sculpins, rockfishes and Japanese anchovy (Engraulis japonicus) were common in the diet of harbour seals, but made up a very small proportion of fisheries catches in Erimo. The importance of other prey species varied between seasons. Sculpins, greenlings and forage fishes were the top three prey groups for harbour seals in spring by percent modified frequency of occurrence, whereas the most important target groups by percentage mass caught by fisheries were codfishes, cephalopods and other invertebrates. Sculpins and rockfishes remained as important prey items for harbour seals in summer and autumn, in addition to codfishes, snailfishes and blennies. In contrast, the main groups caught by fisheries in summer were other fishes, particularly Japanese amberjack (Seriola quinqueradiata) and various species of sharks and eels, and invertebrates. By autumn, Erimo fisheries had focussed on catching salmon. Salmon were taken by harbour seals as well during this period, but at a relatively lower frequency compared to other prey groups. The results of our study show that although harbour seals consumed several of the prey species targeted by fisheries, the relative importance of these species to seals and fisheries and the seasons in which they were targeted were different. 相似文献
12.
《Deep Sea Research Part I: Oceanographic Research Papers》2007,54(5):732-746
The upwelling of nutrients and iron (Fe) sustains biological production in much of the Southern Ocean. Using a shipboard natural community continuous culture system (Ecostat), we supplied a single added Fe concentration at two dilution rates chosen to examine the effects of variations in realistic growth and loss rates on an Fe-limited algal community in the Antarctic Zone south of Australia. A parallel growout experiment provided “no-dilution” +Fe and −Fe controls. In the continuous flow experiment, phytoplankton biomass was lower and more constant throughout the incubation and major nutrients were never depleted. Nanophytoplankton abundance remained similar in both growout treatments, and therefore, growth of this group did not appear to be Fe-limited. The addition of Fe in a continuous fashion resulted in a community co-dominated by both small diatoms and nanophytoplankton. Increases in dilution rate favored diatom species that were smaller and faster-growing, as well as non-silicified algal groups. Particulate carbon (PC) to particulate nitrogen (PN) ratios increased above the Redfield ratio when Fe was added in a continuous fashion, while biogenic silica (BSi) to PC and PN ratios decreased 2–3 fold in the continuous flow experiment compared to the initial conditions and the parallel growout control experiment. Photosynthetic efficiency increased in the continuous flow treatments above the control but remained significantly lower than in the 1.4 nM Fe addition. The results of our shipboard continuous flow experiments are compared and contrasted with those of the mesoscale Southern Ocean Iron RElease Experiment (SOIREE) carried out at the same site. Our results suggest that increases in natural dilution rates (i.e. vertical turbulent diffusion) in polar Antarctic waters could shift the algal community towards smaller, faster-growing algal species, thus having a major effect on nutrient cycling and carbon export in the Southern Ocean. 相似文献
13.
Biodiversity maps are an important component of ecosystem-based management and conservation. In the past, biodiversity maps were largely generated using patchy occurrence data from a range of data sources. Currently, substantial species occurrence data are readily available for large parts of the world and are accessible programmatically. Considering both the observed and expected changes in species distributions, and hence biodiversity, in response to present and future climate change, it is important to utilise readily available species occurrence databases to generate temporal and spatial biodiversity maps. In this study biodiversity maps were generated for three generic functional groups within the exclusive economic zone of South Africa: zooplankton, fishes and benthos. This was achieved by stacking individual species-distribution maps. Freely available occurrence data from the Ocean Biogeographic Information System (OBIS) were accessed for this purpose. Ensemble species-distribution modelling, employing five widely used statistical methods, was used to generate species-distribution maps for each functional group. The resulting spatial patterns of biodiversity for the three functional groups were largely in agreement with known patterns. The results of this study highlight the value of open-source occurrence and environmental data to generate biodiversity maps that can potentially be used in future spatial prioritisation or planning for management of marine areas and in environmental-change studies. 相似文献
14.
于2012年春季(5月)调查了渤海湾天津近岸海域的网采浮游植物群落,经初步分析发现网采浮游植物共2门17属28种,其中硅藻26种,占种类组成的92.9%;甲藻2种,占种类组成的7.1%。调查海域浮游植物以广温型近岸种为主,主要优势种为柔弱几内亚藻Guinardia delicatula、中华齿状藻Odontella sinensis、布氏双尾藻Ditylum brightwellii和格氏圆筛藻Coscinodiscus granii;调查海域网采浮游植物细胞丰度的分布主要由浮游硅藻的分布所决定,高值区主要分布在塘沽、大港和歧口周围海域;20个站位根据浮游植物的物种及丰度相似性可以划分为5组;浮游植物物种多样性指数在0.43～3.59之间,平均为2.15,多样性指数出现由南、北向中央逐渐缩小的趋势;水温、DO、pH值和无机氮与浮游植物种类组成和细胞丰度分布呈最大等级相关,这4个环境因子是对观察到的群落结构的最好解释。 相似文献
15.
Aiko Tachibana Yuichiro Nishibe Hideki Fukuda Kyoko Kawanobe Atsushi Tsuda 《Journal of Oceanography》2017,73(1):55-65
The tsunami caused by the 2011 off the Pacific coast of Tohoku Earthquake seriously damaged the Pacific coast of northeastern Japan. In addition to its direct disturbance, a tsunami can indirectly affect coastal pelagic ecosystems via topographical and environmental changes. We investigated seasonal changes in the phytoplankton community structure in Otsuchi Bay, northeastern Japan, from May 2011, which was 2 months after the tsunami, to May 2013. The phytoplankton species composition in May 2011 was similar to that observed in May 2012 and 2013. The present results are consistent with the dominant species and water-mass indicator species of phytoplankton in past records. These results suggest that there was no serious effect of the tsunami on the phytoplankton community in Otsuchi Bay. Community analysis revealed that two distinct seasonal communities appeared in each year of the study period. The spring–summer community was characterized by warm-water Chaetoceros species, and dinoflagellates appeared from May to September. The fall–winter community was characterized by cold neritic diatoms, which appeared from November to March. The succession from the spring–summer community to the fall–winter community took place within a particular water mass, and the fall–winter community appeared in both the surface water and the Oyashio water mass, suggesting that water-mass exchange is not the only factor that determines the phytoplankton community structure in Otsuchi Bay. 相似文献
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Yesenia Gallegos-Navarro Scott Monks Sergio García-Ibáñez Agustín A. Rojas-Herrera José Luis Rosas-Acevedo 《新西兰海洋与淡水研究杂志》2019,53(3):377-396
Metazoan parasites communities of marine fishes can include both adults and larval stages of several endoparasite groups that use fishes as intermediate or paratenic hosts. The richness and abundance of parasite species larvae that harbour a fish species can therefore be a good indicator of that species’ role as an intermediate host to endoparasite species.
The parasite communities of two small carangid fishes (Selar crumenophthalmus and Decapterus muroadsi) from Mexican Pacific coasts were quantified and analysed. Five hundred sixty-three carangids (S. crumenophthalmus, n?=?402; and D. muroadsi, n?=?161) were collected between April 2014 and April 2018 from three locations. Twenty-four metazoan parasite species were identified in both hosts: five species of Monogenea (adults), eight of Digenea (7 adults and 1 metacercaria), two of Cestoda (larvae), two of Nematoda (one adult and one larva), two of Acanthocephala (adults), and five of Copepoda. Larval helminths numerically dominated the endoparasite communities of both hosts, suggesting that these carangids are important intermediate hosts for several parasite species. Component parasite community richness and species composition differed between hosts, locations, and sampling years. Variations in host feeding behaviour, and body size were considered as important factors influencing these differences. 相似文献
18.
A microcosm experiment was used to compare the influence of diesel contamination on two benthic salt-marsh communities, one chronically exposed to petroleum hydrocarbons for decades (Louisiana [LA]) and the other relatively uncontaminated (Mississippi [MS]). Initial meiofaunal community composition of the two sites was similar. Higher organic content of MS sediments should have reduced bioavailability, and thus the toxicity of hydrocarbons relative to the LA site. Nevertheless, although responses to diesel contamination at the two sites were generally qualitatively similar, a species-specific and several community-response variables were influenced to a much greater degree in the MS community. In particular, the abundance of total nauplii, ostracods, and copepods were negatively impacted to a greater extent in MS than in LA, as was grazing by ostracods on benthic microalgae. Nematode:copepod ratios in contaminated sediments were much higher in MS than in LA sediments. Pseudostenhelia wellsi (a benthic copepod) nauplii suffered greater adverse effects of diesel in MS than in LA. We conclude that the MS community was more sensitive to diesel contamination than was the LA community. The differential sensitivity is presumably a manifestation of different tolerances to hydrocarbon contaminants, mediated by a higher proportion of more tolerant species and/or increased tolerance among individual species in LA. Although the MS site was more sensitive to diesel contamination, qualitative response of the LA and MS communities were similar, and comparable to previous studies of diesel contamination. The spatial and temporal consistency of diesel impacts on salt-marsh communities suggests that hydrocarbon contamination results in predictable community responses. Specifically, crustacean (e.g. copepods, ostracods, and nauplii) benthos are most sensitive to hydrocarbons. Reductions in abundance and grazing activity of crustaceans leads to enhanced algal biomass, reduced copepod diversity, and alters competitive interactions among meiofauna. 相似文献
19.
2013年5月对辽东湾中部的大型底栖生物进行了调查,分析了该海域底栖生物的种类组成、丰度、生物量、群落结构及其与环境因子的关系。调查海域共发现大型底栖生物70种,包括多毛类24种,甲壳类18种,软体动物20种,棘皮动物7种,纽虫1种。相对重要性指数大于100的种类有14种,排名前3位的分别是日本游泳水虱、毛蚶、日本长尾虫。底栖动物丰度平均值为244.2个/m~2,生物量为52.52 g/m~2,棘皮动物是生物量的重要贡献者。多样性指数平均值为3.24,丰度生物量比较曲线分析结果认为调查海域大型底栖动物群落未受到干扰,底栖生物群落的结构相似性较低,在20%的相似程度上可分为5个组。底层水中溶解氧含量是影响底栖生物的主要因素,不同底质条件是影响底栖生物生物量和群落结构的重要因素。 相似文献
20.
2010-2011年长江河口及邻近水域春夏季仔稚鱼群落结构及其多样性的研究 总被引：2，自引：2，他引：0
根据2010—2011年春夏季对长江河口及邻近水域进行了仔稚鱼生态调查,应用单元和多元统计方法分析了春夏季长江河口及邻近水域仔稚鱼群落结构。4个航次调查共获得27个种类的仔稚鱼,隶属5目14科。优势种类主要包括鳀Engraulis japonicus、凤鲚Coilia mystus、康氏小公鱼Stolephorus commersonii、鮻Liza haematocheila、黄姑鱼Nibea albiflora、黄鳍刺虎鱼Acanthogobius flavimanus和寡鳞飘鱼Pseudolaubuca engraulis等。Shannon-Weaver指数(H′)在调查周期内的波动幅度较大,且2011年明显低于2010年。仔稚鱼群落结构和多样性指数春季年间较夏季年间差异性显著。调查区夏季群落结构年间相似性不高,春季群落结构格局年际变化则较明显。聚类分析表明,春夏季长江河口近岸水域仔稚鱼群落可划分为2个站位组,分别对应于长江河口淡水水域和长江口咸水水域。淡水水域组群落和咸水水域组群落总丰度与盐度相关性较高。表明盐度可能是造成长江河口仔稚鱼群落结构时空差异性的主要原因。 相似文献