Alterations to the relative species-abundance of ascidians and barnacles in a fouling community due to screens

1980 ◽  
Vol 31 (2) ◽  
pp. 147 ◽  
Author(s):  
JI Marshall ◽  
FWE Rowe ◽  
RP Fisher ◽  
DF Smith
Keyword(s):  
Species Composition ◽  
Species Abundance ◽  
Mesh Size ◽  
Fouling Community ◽  
Bryozoan Species ◽  
Styela Plicata ◽  
Barnacle Species ◽  
Fouling Organisms

The species composition and abundance of a community of fouling organisms can be altered by shielding the surface to be settled with fibreglass screen of 1.0 mm mesh size. Settlement and survival of two barnacle species is nearly precluded, while that of the ascidians Pyura praeputialis, Styela plicata, S. pedata and Diplosoma listerianum and of several bryozoan species is greatly enhanced. S. pedata was found to survive almost exclusively on screened plate surfaces.

scholarly journals Fouling organisms on Perna perna mussels: is it worth removing them?

2007 ◽  
Vol 55 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Fabrício S. de Sá ◽  
Rosebel C. Nalesso ◽  
Karla Paresque
Keyword(s):  
Species Abundance ◽  
Perna Perna ◽  
Fouling Community ◽  
Bugula Neritina ◽  
Monthly Basis ◽  
Fouling Control ◽  
Eastern Brazil ◽  
Long Line ◽  
Perna Perna Mussel ◽  
Fouling Organisms

Perna perna mussel spat were suspended from ropes on a long-line cultivation, at Coqueiro´s Beach, Anchieta, South-eastern Brazil, in order to quantify the fouling community structure and its effects on growth and biomass of mussels. Half of the ropes had the fouling removed monthly, half had the foulingleft until the end of the experiment. Monthly samples of thirty mussels from each group were measured and their biomass determined. The fouling organisms were identified, quantified and their biomass evaluated on a monthly basis. After ten months, mussels on the cleaned treatment were significantly larger and heavier (ANOVA; P < 0.05; Bonferroni: unfouled > fouled), showing that fouling reduced mussel development. The most abundant epibiont organisms in terms of biomass were the algae Polysiphonia subtilissima (29%) and Ulva rigida (10.3%), followed by the bryozoans Bugula neritina (13.6%) and Perna perna spat (10.6%). Over 97 taxa and 42,646 individuals were identified, crustaceans being the most abundant group, predominantly one amphipod Cheiriphotis megacheles (12,980 ind.). Species abundance was positively correlated with algal biomass, revealing the influence of algae on vagile fauna, which provide both food and shelter. The benefits of fouling removal are discussed because the majority of species are important feeding items to fishes and yet, the costs of its fouling control added to the associated mussel spat loss make this fouling removal of questionable value.

scholarly journals Effect of disturbance on plant species abundance and density distribution in tropical forest of Sunsari district, Eastern Nepal

2016 ◽  
Vol 6 (1) ◽  
pp. 1-12
Author(s):  
Tilak Prasad Gautam ◽  
Tej Narayan Mandal
Keyword(s):  
Carbon Sequestration ◽  
Species Composition ◽  
Tropical Forest ◽  
Tropical Forests ◽  
Tree Species ◽  
Forest Disturbance ◽  
Species Abundance ◽  
Forest Degradation ◽  
Tree Density ◽  
Shrub Species

The disappearance of global tropical forests due to deforestation and forest degradation has reduced the biodiversity and carbon sequestration capacity. In these contexts, present study was carried out to understand the species composition and density in the undisturbed and disturbed stands of moist tropical forest located in Sunsari district of eastern Nepal. Study revealed that the forest disturbance has reduced the number of tree species by 33% and tree density by 50%. In contrary, both number and density of herb and shrub species have increased with forest disturbance.

scholarly journals Ecological studies of mayflies (Insecta, Ephemeroptera): Can sampling effort be reduced without losing essential taxonomic and ecological information?

2018 ◽  
Vol 48 (2) ◽  
pp. 137-145 ◽  
Author(s):  
Yulie SHIMANO ◽  
Mylena CARDOSO ◽  
Leandro JUEN
Keyword(s):  
Species Composition ◽  
Species Abundance ◽  
Taxonomic Resolution ◽  
Sampling Effort ◽  
Ecological Information ◽  
Genus Level ◽  
Level Data ◽  
Group A ◽  
Species Richness And Abundance ◽  
Laboratory Time

ABSTRACT The present study evaluated the potential for the reduction of sampling effort in studies of ephemeropteran nymphs in Brazilian Amazon streams, Pará State, Brazil, without the loss of ecological information (species composition, abundance, and richness), and the congruence of different levels of taxonomic resolution (morphospecies, genus, family and functional group). Test groups of 15, 10 and five subsamples were selected from the 20 subsamples collected per stream (40 streams sampled), and were compared in terms of their species richness and abundance (ANOVA), and composition (Procrustes). Taxonomic resolution was also analyzed in Procrustes. Species abundance (F(3, 156) = 25.426; p < 0.001) and richness (F(3, 156) = 13.866, p < 0.001) varied significantly among sample groups, while the results of the 15-S group were statistically similar, in both cases, to those of the 20-S group. A similar pattern was found for species composition. The genus-level taxonomic resolution produced results 99% similar to those found for the species-level data. The results indicate that the reduction in sampling effort from 20 to 15 subsamples per site and a genus-level taxonomic resolution would not affect the reliability of analyses significantly. A reduction of five samples per site would result in a decrease of effort in the field and the amount of material to be processed, reducing laboratory time. In addition to a reduction in the time and resources needed to identify specimens, the adoption of a genus-level taxonomic resolution could help minimize errors of under- or over-estimation in the processing of the results.

Epibenthic community structure in Port Phillip Bay, Victoria, Australia

2000 ◽  
Vol 51 (7) ◽  
pp. 689 ◽  
Author(s):  
Brian F. Cohen ◽  
David R. Currie ◽  
Matthew A. McArthur
Keyword(s):  
Community Structure ◽  
Species Abundance ◽  
Habitat Type ◽  
Demersal Fish ◽  
Asterias Amurensis ◽  
Styela Plicata ◽  
Strong Trend ◽  
Epifaunal Community ◽  
Inshore Waters ◽  
Total Species

Epibenthic community structure in Port Phillip Bay was examined from quantitative diver samples collected at 30 depth-stratified stations during 1998. Analysis of variance showed a strong trend of decreasing epibenthic abundance, biomass and species diversity with depth. Reductions in these three parameters were most pronounced over shallow inshore waters and could be attributed largely to decreases in the abundance of the heavy, mat-forming ascidian Pyura stolonifera with depth. Four epifaunal community groupings, closely reflecting differences in sediment and habitat type within the bay, were identified from ordinations of species abundance and biomass data. The four epifaunal groupings also closely matched distributional patterns observed in other studies in both demersal fish and infaunal communities. Epifaunal communities in the bay were dominated by filter-feeding organisms which accounted for nearly 95% of the total species abundance and 98% of the total species biomass. Seven of the 63 epibenthic organisms collected during the survey are exotic introductions to the bay (Sabella spallanzanii, Ascidiella aspersa, Styela clava, Styela plicata, Ciona intestinalis, Pyromaia tuberculata and Asterias amurensis). As many of these species are widespread and abundant (35% of all individuals), their effects on the ecology of Port Phillip Bay are likely to be significant.

BIOMASS EXPORTATION FROM OFFSHORE PRODUCTION PLATFORMS IN EAST TEXAS

1981 ◽  
Vol 1981 (1) ◽  
pp. 715-720
Author(s):  
Nick Fotheringham
Keyword(s):  
Marine Ecosystem ◽  
Benthic Fauna ◽  
Control Site ◽  
Hermit Crabs ◽  
Fouling Community ◽  
Offshore Production ◽  
Significant Difference ◽  
Fish Gut ◽  
Fouling Organisms ◽  
Offshore Production Platforms

ABSTRACT Studies of the structure and development of the fouling community on active offshore production platforms in the Buccaneer Field, Texas, indicated that energy accumulated within this community was exported to components of the adjacent marine ecosystem along three major pathways. The most apparent pathway was through grazing fish. Gut content analyses of 191 fish representing 27 species indicated that the spadefish (Chaetodipterus faber), sheepshead (Archosargus probatocephalus), crested blenny (Hypleurochilus geminatus), cocoa damselfish (Pomacentrus variabilis), and cubbyu (Equetus acuminatus) feed extensively on fouling organisms. A second pathway linked the fouling community to the benthic fauna living beneath the platforms, which was apparently enriched by consumption of barnacles and other invertebrates dislodged from the platform legs by wave and current stresses, abrasion by boats, and foraging fish. Several fouling species, which did not occur on the structures themselves, were found on dislodged barnacle shells and gastropod shells occupied by hermit crabs. Thus, accumulation of biomass beneath the structures is apparently increased by the presence of these shells. The third pathway linked the fouling community to planktivorous fish and invertebrates through the release of planktonic larvae by fouling organisms. A significant difference (p &lt; 0.05) was found in the proportion of these larvae in the total plankton between stations within Buccaneer Field and those at a control site 8 kilometers east of the field.

Seasonal Occurrence of Adult Carabid Beetles (Coleoptera: Carabidae) in West-Central Illinois

2020 ◽  
Vol 55 (3) ◽  
pp. 329-343
Author(s):  
Kenneth W. McCravy ◽  
Jason E. Willand
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Tallgrass Prairie ◽  
Activity Patterns ◽  
Species Abundance ◽  
Abundant Species ◽  
Early Summer ◽  
Carabid Beetles ◽  
West Central ◽  
Central Illinois

Abstract The Carabidae is a diverse family of beetles with many species of interest in conservation and biological control. Carabid beetle adult seasonal activity patterns were studied in a west-central Illinois forest/reconstructed tallgrass prairie matrix over a 2-yr period using pitfall traps. We found a threefold or greater difference in carabid abundance between years. Despite lower abundance, a second year of sampling yielded seven previously undetected species. Abundance and species richness were greatest in May–July and lower in August–October. Relative abundance and species richness were consistent among months between years. Shannon diversity and effective number of species were lowest in June and July. Cyclotrachelus sodalis (LeConte) and Chlaenius platyderus Chaudoir were the two most abundant species, comprising 54.3% of total captures. These species were most abundant in July and June, respectively. Most species showed greatest abundance in spring or early summer, and declined thereafter. Collections of several species were suggestive of bimodal seasonal patterns. Carabid species composition differed significantly among months, but not between years. Our results document seasonal variation in carabid abundance and species composition, and show that sampling throughout the growing season, and multiple sampling years, provide substantial benefits for assessments of carabid diversity in this region.

Early patterns of revegetation of artificial earthen mounds in a northern mixed prairie

1992 ◽  
Vol 70 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Charles E. Umbanhowar Jr.
Keyword(s):  
Species Composition ◽  
Key Words ◽  
Species Abundance ◽  
Bare Soil ◽  
Compositional Variation ◽  
Stem Density ◽  
Mixed Prairie ◽  
Outer Perimeter ◽  
Species Abundance Data ◽  
Key Words Colonization

Patches of bare soil are thought to be important to the diversity and structure of North American grasslands. In 1987, 45 7.5-dm diameter artificial earthen mounds were built in low-, mid-, and high-prairie types to experimentally study the effects of mound location on patterns of mound revegetation. Stem densities and species abundance data were recorded every other week during the summers of 1987 and 1988. Few stems were recorded in 1987, and stem density more than quadrupled in 1988, but less than 1 % of all stems were seedlings. Grass stem densities were significantly higher on low-prairie mounds than mid- or high-prairie mounds and were concentrated in the outer perimeter of mounds. Forb stem densities did not vary significantly between prairie types or on-mound position. Mound species composition closely resembled surrounding vegetation, reflecting between and within prairie-type compositional variation. Key words: colonization, disturbance, earthen mounds, northern mixed prairie, patch, revegetation.

Does the Mesh Size of the Plankton Net Affect the Result of Statistical Analyses of the Relationship Between the Copepod Community and Water Masses?

Crustaceana ◽  
2011 ◽  
Vol 84 (9) ◽  
pp. 1069-1083 ◽  
Author(s):  
Chun-Ming Shin ◽  
Kuo-Ping Chiang ◽  
Chih-Jung Wu
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Mesh Size ◽  
Water Masses ◽  
Statistical Analyses ◽  
The East China Sea ◽  
Copepod Community ◽  
The Difference ◽  
The Relationship ◽  
Net Affect

AbstractWe examined if the results of statistical analyses of the relationship between copepod communities and water masses would be affected by the mesh size of the plankton net, by comparing abundance and species composition of copepods in plankton samples collected by plankton nets of different mesh sizes. Our samples were collected during the summer of 2006 in the East China Sea (ECS) by plankton nets with mesh sizes of 100 and 330 μm. The abundance of copepods collected by the 100 μm-mesh plankton net was about two orders of magnitude higher than that collected by the 330 μm-mesh plankton net. The difference in abundance was mainly due to the loss of small-sized copepods in the samples collected by the plankton net with the larger mesh. Species richness was higher in samples collected by the 100 μm-mesh net and Piélou's evenness was generally higher in samples collected by the 330 μm-mesh net. Although species composition of copepods varied in samples collected by plankton nets with different mesh sizes, the statistical analysis of the relationship between the copepod community and the water masses in these samples appeared not to be affected.

scholarly journals Variations in Total Species Richness and the Unevenness of Species Abundance Distribution between Two Distant Conus Communities (Neogastropoda): A Case Study in Mannar Gulf (India)

2019 ◽  
pp. 1-18
Author(s):  
Jean Béguinot
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Species Abundance ◽  
Species Abundance Distribution ◽  
Abundance Distribution ◽  
Marine Gastropods ◽  
Total Species Richness ◽  
Species Recruitment ◽  
Total Species

The genus Conus forms a conspicuous and rather homogeneous group within marine Gastropods. This makes it all the more interesting to focus on the sub-communities formed by Conus species and to analyze the potential specificities in the internal organization of species in these communities, in particular species richness, species abundance distribution and the effect of geographical distance between communities on differences in their respective species composition. Accordingly, two Conus communities along the coast in Mannar Gulf (India), separated by 80 km, are considered. Reliable analysis requires, first, to treat exhaustive data from complete samplings or, else – as here – to implement an appropriate extrapolation procedure to complete numerically the partial samplings. After numerical completion, substantial differences were highlighted between the two communities, not only in terms of true (total) species richness but, even more, as regards the profile and the average unevenness of the distributions of species abundance. Also, significant dissimilarity in species composition was found between the two communities, that may be tentatively attributed to either deterministic distance decay in similarity of species composition or, alternatively, to the persistence in the stochastic process of species recruitment from the regional stock of Conus planktonic larvae. This preliminary study yet requests to be complemented by other similar case studies, before drawing any safer interpretative conclusions.

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