scholarly journals MEIOBENTHIC COMMUNITY OF SUNGAI PULAI SEAGRASS BED, MALAYSIA

2008 ◽  
Vol 33 (1) ◽  
pp. 17-20
Author(s):  
Zaleha Kassim ◽  
Farah Diyana ◽  
Mohd Fathi ◽  
Amirudin Ahmad
Keyword(s):  
Cluster Analysis ◽  
Community Structure ◽  
Seagrass Bed ◽  
Lower Estuary ◽  
Significant Contributor ◽  
Environmental Setting ◽  
Sea Area

Meiobenthos inhabiting the seagrass bed of Sungai Pulai estuary, Johor, was studied for the differences in community structure. Sampling was carried out using a hand corer during the lowest tide in December 2006. Three stations were chosen that were located at the upper estuary, lower estuary and at the sea area. Cluster analysis dendrogram of Bray-Curtis similarity showed the similarity level at about 70-75% and from the MDS plot, it is found that communities at upper estuary were separated from those at lower estuary and at sea. The differences in environmental setting were thought as the significant contributor to the distribution of meiobenthos among the stations.

scholarly journals Characteristics of Benthos communities in Laoting area of Hebei Province

2020 ◽  
Vol 206 ◽  
pp. 02024
Author(s):  
Li Guanglou ◽  
Cao Hongmei ◽  
Ye wei
Keyword(s):  
Community Structure ◽  
Benthic Community ◽  
Dominant Species ◽  
Diversity Index ◽  
Hebei Province ◽  
Benthic Community Structure ◽  
Number Of Species ◽  
Evenness Index ◽  
Sea Area ◽  
Richness Index

According to a survey of benthos in the Laoting sea area of Hebei Province on May 24th 2019, a total of 40 benthos species were obtained, of which mollusks have the largest number, followed by annelids and arthropods. The dominant species are Sternaspis sculata and Ringicula doliaris. The number of species obtained in this survey is much lower than the historical average. The diversity index is significantly lower than that in the April 2008 survey, and the evenness index and richness index have declined slightly, indicating that the benthic community structure in this sea area tends to be simplistic, stability tends to deteriorate.

The community structure of larval fish populations in an area of the Celtic Sea in 1998

2002 ◽  
Vol 82 (4) ◽  
pp. 641-648 ◽  
Author(s):  
S. Acevedo ◽  
O. Dwane ◽  
J.M. Fives
Keyword(s):  
Community Structure ◽  
Fish Species ◽  
Larval Fish ◽  
Single Species ◽  
Coastal Fish ◽  
Larval Stages ◽  
Celtic Sea ◽  
Sea Area ◽  
Insight Into ◽  
Fish Distributions

Ichthyoplankton from an area in the Celtic Sea was studied to provide an insight into the fish larval community structure in March, May and June 1998. Three station groups were defined each month, Neritic, Transition and Oceanic. The Neritic assemblages included larval stages of coastal fish species and the Oceanic assemblages included mesopelagic and high-oceanic fish species which were not recorded from any of the Neritic stations. The Transition stations usually contained species characteristic of both the Neritic and Oceanic assemblages. It is suggested that these broad patterns of larval fish distributions are constant features of the Celtic Sea area, probably related to the spawning location of the adults. The area is, in general, species poor, with the Oceanic stations usually dominated by a single species, indicating the presence of a large spawning school of fish.

Day–night change in fish community structure in a seagrass bed in subarctic waters

2018 ◽  
Vol 84 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Hiroki Tanaka ◽  
Susumu Chiba ◽  
Takashi Yusa ◽  
Jun Shoji
Keyword(s):  
Community Structure ◽  
Fish Community ◽  
Fish Community Structure ◽  
Seagrass Bed

scholarly journals Fish assemblages in a tidal flat

2003 ◽  
Vol 46 (2) ◽  
pp. 233-242 ◽  
Author(s):  
Ana Lúcia Vendel ◽  
Sabine Granado Lopes ◽  
César Santos ◽  
Henry Louis Spach
Keyword(s):  
Cluster Analysis ◽  
Community Structure ◽  
Tidal Flat ◽  
Seasonal Changes ◽  
Dominant Species ◽  
Fish Assemblages ◽  
Seasonal Pattern ◽  
Abundant Species ◽  
Structure Index ◽  
Total Capture

Studies were carried out on fish assemblages in a tidal flat. Samples were obtained monthly at low tide of the half moon in the tidal flat of Paranaguá Bay, Brazil, with two seine nets, one with a 1 mm mesh, 30 m in length and 3 m in height and another with a 10 mm mesh, 65 m in length and 2 m in height. A total of 8,890 fish were captured, comprising 24 families and 53 species. The most abundant species were Harengula clupeola and Atherinella brasiliensis, which represented 63.4% of the total, capture. A seasonal tendency was observed in the abundance of fishes, with less fishes being captured during winter and part of spring. The number of species showed a seasonal pattern, with the gradual decrease through winter and a marked increase in summer. The community structure index indicated seasonal changes in the assemblage. The faunistic similarities between months separated the 12 months into four major groups. The seasonal pattern was apparent in the numerically dominant species and the Cluster Analysis revealed five main groups.

scholarly journals Modelling community structure and species co-occurrence using fishery observer data

2016 ◽  
Vol 73 (7) ◽  
pp. 1750-1763 ◽  
Author(s):  
Jeffrey Robert Pulver ◽  
Hui Liu ◽  
Elizabeth Scott-Denton
Keyword(s):  
Cluster Analysis ◽  
Community Structure ◽  
Gulf Of Mexico ◽  
Reef Fish ◽  
Efficient Method ◽  
Probabilistic Models ◽  
Distinct Species ◽  
Common Species ◽  
Species Relationships ◽  
Correlation Measure

Abstract In this study, we modelled fishery observer data to compare methods of identifying community structure using cluster analyses to determine stratifications and probabilistic models for examining species co-occurrence in the Gulf of Mexico deepwater reef fish fishery. Comparing cluster analysis methods, the correlation measure of dissimilarity in combination with average agglomerative linkage was the most efficient method for determining species relationships using simulated random species as a comparison tool. Cluster analysis revealed distinct species stratifications and in combination with multiscale bootstrapping generated probabilities indicating the strength of stratifications in the fishery. A more parsimonious approach with probabilistic models was also developed to quantify pairwise species co-occurrence as random, positive, or negative based on the observed vs. expected fishing sets with co-occurrence. For the most common species captured, the probabilistic models predicted positive or negative co-occurrence between 84.2% of the pairwise combinations examined. These methods provide fishery managers tools for determining multispecies quota allocations and offer insights into other bycatch species of interest.

Weed community structure in spring-seeded crops in Manitoba

1991 ◽  
Vol 71 (4) ◽  
pp. 1069-1080 ◽  
Author(s):  
A. G. Thomas ◽  
M. R. T. Dale
Keyword(s):  
Cluster Analysis ◽  
Community Structure ◽  
Weed Ecology ◽  
Analysis Techniques ◽  
Temperature And Precipitation ◽  
Weed Communities ◽  
Geographic Regions ◽  
Production Practices ◽  
Using Data ◽  
And Cluster Analysis

The phytosociological structure of weed communities in spring wheat, barley, oats, flax, and canola was investigated using data collected during a 3-yr survey of 1384 fields in Manitoba. Fields were surveyed during July and August, after the application of all herbicides. Association and cluster analysis techniques, using the presence or absence of species in a field, were employed to distinguish co-occurring groups of species. Only a small number of significant positive and negative associations were found between species and only minor clusters with a few species were formed at low similarity levels. These results indicated that the weed community was composed of species responding to conditions more or less independently of each other. A comparison of weed associations among the five crops and four geographic regions in the province indicated that the weed community structure was determined largely by climatic variables. The pattern of weed association in the four geographic regions was correlated with differences in temperature and precipitation during the spring and summer. The lack of floristic differentiation was attributed to the fact that production practices were similar for the five spring-seeded crops. Key words: Weed communities, weed ecology, cluster analysis, association analysis

Studies on the Community Structure of Phytoplankton in the Sea near Sanmen Bay

2012 ◽  
Vol 518-523 ◽  
pp. 502-508 ◽  
Author(s):  
Gen Hai Zhu ◽  
Jian Qian ◽  
Li Hong Chen
Keyword(s):  
Community Structure ◽  
Dominant Species ◽  
Red Tide ◽  
Skeletonema Costatum ◽  
Continuous Observation ◽  
Dominant Group ◽  
Average Cell ◽  
Cell Abundance ◽  
Sanmen Bay ◽  
Sea Area

This paper reports the phytoplankton investigation results which were collected in 15 observation stations and a day-night continuous observation station in the sea area near Sanmen Bay (29° 00'00 "~ 29° 10'26 "N, 121° 34'43" ~ 121° 47'06 "E) in spring(April), summer (July), autumn (October) of 2007 and winter (January) of 2008. After microscopic observation and identification, a total of 6 phyla, 56 genera, 146 species were identified in the sea near Sanmen Bay. The seasonal species change was spring (101)> autumn (96)> summer (96)> winter (85). The cell abundance of phytoplankton in the sea near Sanmen Bay was 0.72103～1.3106 cells /dm3, and the average cell abundance was 5.13104 cells /dm3. The mean cell abundance in winter was 1.27105cells/dm3 >4.72104cells/dm3 in autumn > 1.63104 cells/dm3 in spring > 2.51103cells/dm3 in summer. During the 24-hour continuous observation, in the day time, particularly in the afternoon, the photosynthesis was strong, and the cell abundance of phytoplankton was high; at night, especially in the latter half of the night or wee hours, the photosynthesis was weak, and the cell abundance of phytoplankton was low. The dominant species of phytoplankton in the Sanmen Bay was Skeletonema costatum. Ecological types of phytoplankton can be divided into three groups: (1) inner bay and coastal temperate group; (2) eurythermal and euryhaline group; (3) warm water off-shore group. Inner bay and coastal eurythermal and euryhaline group was the dominant group. The amounts of other groups were less. Totally 64 red-tide species were observed in the sea area near Sanmen Bay, of which, diatoms was predominant, 40 species; dinoflagellates was 19 species; Cyanophyta was 2 species; Euglena、Chrysophyceae and Protozoa was 1 specie respectively. The average cell abundance of the main red-tide organisms in the sea area near Sanmen Bay was 5.6102 cells/dm3～1.2105 cells/dm3. The dominant species composition and community structure of phytoplankton were mainly composed of diatoms, such as Skeletonema costatum, Ditylum brightwelli, Coscinodiscus jonesianus, Thalassiosira eccentrica, Leptocylindrus danicus, Chaetoceros lorenzianus; pyrrophyta, such as Ceratium fusus, Ceratium tripos, Ceratium furca etc.

scholarly journals STUDI KEANEKARAGAMAN DAN STRUKTUR KOMUNITAS PERIFITON DI PERAIRAN SUNGAI COBAN RONDO MALANG

2020 ◽  
Vol 1 (2) ◽  
pp. 93-97
Author(s):  
Zainal Abidin
Keyword(s):  
Water Quality ◽  
Cluster Analysis ◽  
Community Structure ◽  
Environmental Changes ◽  
Aquatic Organisms ◽  
Dominance Index ◽  
Periphyton Community ◽  
Similarity Indices ◽  
And Cluster Analysis ◽  
Index Value

Periphyton is a community of microorganisms that live attached to or adjacent to a substrate sink. For aquatic organisms, periphyton habitats have a relatively fixed. With it is so, the changes of water quality and substrate greatly affects the composition of his life and abundance. Periphyton composition and abundance depends on the tolerance or sensitivity to environmental changes. This study aims to determine each periphyton community in responding to changes in habitat quality by way of adjustment in community structure. The methodology used in this prektikum involves taking data from four stations along the river Coban Rondo, in each station there are 3 replicates. And take measurements of factors such environments as supportive data turbidity, flow rate, pH, and depth. Analyzed using Simpson's Dominance Index to determine the type of periphyton dominance, as well as morisita similarity indices and cluster analysis. The results showed that the diversity in each station belonging to the category of high (H more than 3.32) because the obtained value of the index H' between 3.2 to 3.48. Species that dominate from the four stations is Pinularia with an average Index Value Important (IVI) 31,5.

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