Abundance Biomass Comparison Research Articles

Numerical analyses of soft bottom invertebrates to diagnose the pollution in tropical coastal waters.

Soft bottom benthic organisms especially polychaetes are known to adapt as r or k selected strategies to different gradients of pollution. This will result in changes of benthic community structure from that of normal structure. There are a number of techniques to assess the impact of pollution on benthic community structure. Hence, to test this hypotheses some of the univariate and multivariate techniques were applied to soft bottom macro-invertebrates data of coastal waters of Mangalore, central west coast of India, a hot-spot area. Univariate techniques such as Pearson Rosenberg Model (PRM), abundance biomass comparison curve (ABC), geometrical class distribution, dominance-diversity curve, benthic community structure indices and multivariate techniques such as cluster classification, multidimensional scaling (MDS) and principal component analysis (PCA) were used to discriminate and diagnose the disturbance among the sites. Effectiveness and applicability of some of the above techniques are highlighted and discussed with the present set of data for environmental impact assessment studies.

The application of a Marine Biotic Index to different impact sources affecting soft-bottom benthic communities along European coasts

Following the European Water Framework Directive (2000/60/EC), the authors proposed, in a previous contribution, a Marine Biotic Coefficient (BC) to establish the ecological quality of soft-bottom benthos within European estuarine and coastal environments. The present study examines the application of the BC to the Atlantic (North Sea; Bay of Biscay; South of Spain) and Mediterranean (Spain and Greece) European coasts. The investigation assesses also the usefulness of the BC, in relation to different impact sources (e.g. drilling cuts with ester-based mud, submarine outfalls, heavy metals, industrial and mining wastes, jetties and sewerage works). The results obtained are consistent with those obtained using several methods and parameters, such as richness, diversity, evenness, Abundance–Biomass comparison plots and univariate and multivariate statistical analyses. The BC values provide a simple and clearly defined way to establish the ecological quality of soft-bottom benthos, complementary to the above mentioned methods.

Seasonal changes in density, biomass, and diversity of estuarine fishes in tidal mangrove creeks of the lower Caeté Estuary (northern Brazilian coast, east Amazon)

The present study investigated the assemblage of fish species in an intertidal mangrove forest during high tide in a macrotide region. We describe the seasonal changes in the fish assemblage composition in relation to biomass, density, and species number in tidal creeks of the Furo do Meio, Caete Estuary, Brazil. A total of 29 107 individuals of 49 species in 26 families were caught using a block net. Their total weight was 526 kg (total density 0.11 ind. m -2 and total biomass 2.1 g m -2 ). Analysis of the catch data showed that the number of species varied significantly between creeks, and that total fish biomass differed significantly between seasons. The densities and biomass of the 2 most important species, Cathorops pleurops and Colomesus psittacus, were significantly different between seasons. The densities and biomass of C. pleurops, Pterengraulis atherinoides, Pseudauchnipterus nodosus, and Stellifer naso showed significant temporal differences. Significant differences between creeks were observed in the density and biomass of Anchovia clupeoides and Rhinosardinia amazonica. The abundance-biomass comparison (ABC) plots for the fish fauna in the creeks of the Furo do Meio showed that the dominant species increased in number and weight at the beginning of the rainy season. As a result of increased rainfall in March and April, salinity declined to values between 6 and 8 psu. At that time, the dominant species made up more than 60% of the total biomass and density and Hill's index of diversity (N1) declined, whereas the number of species (NO) and evenness (E2) did not change. After April, rainfall decreased, and density and biomass returned to levels similar to those before the rainy season. The number of species and the density and biomass in the mangrove tidal creeks are compared with published data for other tropical and subtropical estuaries. Migration trends were inferred from the results of the seasonal fluctuations of density and biomass of the most important species in the Furo do Meio, and are compared with data from other studies in the main channel of the Caete Estuary.

Analysis of macrobenthic community structure in relation to different environmental sources of contamination in two littoral ecosystems from the Gulf of Cádiz (SW Spain)

Selected chemicals in sediments and the abundances and biomasses of macrobenthic species were determined at seven stations from two littoral ecosystems in the Gulf of Cadiz. The marine macrobenthic communities were described in both ecosystems that are subjected to different sources and levels of contamination. A qualitative relationship between source of contamination and biological effects for each station is proposed and the results of the univariate and multivariate analysis used are discussed. Univariate analyses using conventional community descriptive parameters (number of species, abundance and richness, Shanon–Weaver and evenness indices) and the numerial contribution of major taxonomic groups (i.e., Polychaeta, Oligochaeta, Mollusca and Crustacea) could not be used as a means of classifying the sites as clean or polluted with respect to the contamination measured. The results showed that multivariate methods are much more sensitive than univariate techniques. Abundance/biomass comparison (ABC) plots classified the macrobenthic communities into different classes mainly related to organic contamination. However, this analysis did not reflect the alteration due to inorganic sources of contamination. This kind of analysis is valuable for the evaluation of alteration of effects but it cannot discriminate between two different phenomena: pollution (adverse effect associated with chemical concentrations) and alteration (adverse effect associated with chemical concentrations or with natural variations).

Effects of physical trawling disturbance in a previously unfished sheltered Scottish sea loch

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 162:227-242 (1998) - doi:10.3354/meps162227 Effects of physical trawling disturbance in a previously unfished sheltered Scottish sea loch Ian D. Tuck*, Stephen J. Hall**, Mike R. Robertson, Eric Armstrong, David J. Basford Fisheries Research Services, Marine Laboratory Aberdeen (FRS MLA), PO Box 101, Victoria Rd, Aberdeen AB11 9DB, Scotland, UK *E-mail: tucki@marlab.ac.uk **Present address: School of Biological Sciences, Flinders University of South Australia, GPO Box 2100, Adelaide, South Australia 5001, Australia The effects of trawling disturbance on a benthic community were investigated with a manipulative field experiment in a fine muddy habitat that has been closed to fishing for over 25 yr. We examined the effects of extensive and repeated experimental trawl disturbance over an 18 mo period on benthic community structure and also followed the subsequent patterns of recovery over a further 18 mo. During the period of trawl disturbance the number of species and individuals increased and measures of diversity (Shannon's exponential H' and Simpson's reciprocal D) and evenness decreased in the trawled area relative to the reference site. The cirratulid polychaetes Chaetozone setosa and Caulleriella zetlandica were found to be most resistant to disturbance, whilst the bivalve Nuculanitidosa and polychaetes Scolopolos armiger and Nephtys cirrosa were identified as sensitive species. Multivariate analysis and abundance biomass comparison plots confirmed that community changes occurred following disturbance, with some differences between treatment and reference sites still apparent after 18 mo of recovery. Physical effects, examined with Side-scan and RoxAnn, were identifiable immediately after disturbance, but were almost indistinguishable after 18 mo of recovery. Such long recovery times suggest that even fishing during a restricted period of the year may be sufficient to maintain communities occupying fine muddy sediment habitats in an altered state. Fishing disturbance · Physical disturbance · Trawling · Community dynamics Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 162. Publication date: February 12, 1998 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1998 Inter-Research.

The Effect of Aquaculture Practices on the Benthic Macroinvertebrate Community of a Lagoon System in the Bay of Cádiz (Southwestern Spain)

Monthly quantitative Ekman-Birge grab sampling was used to characterize and compare the composition and structure of the benthic macroinvertebrate community inhabiting semi-enclosed polyculture lagoons (SPL) (three sampling sites) and enclosed monoculture ponds (EMP) (two sampling sites) of a lagoonal system of the Bay of Cadiz. The two areas differed considerably in habitat characteristics and aquaculture management. The SPL area was characterized by low rates of water exchange, low fish densities, and the presence of a macroalgal cover. In the EMP area, there was a complete exchange of water daily (by pumping) and a supply of food pellets, density of fish was high, and no vegetative cover was present. There were considerable differences in species composition between habitats with different culture methods: 11 of the 21 most abundant species were exclusive to one or the other. Several epibenthic species were abundant in the polyculture lagoon but were low in density or were absent in monoculture ponds. Some infaunal species, on the other hand, were more abundant in the monoculture ponds. Univeriate measures of community structure (abundance and biomass, Margalef’s species richness, Shannon-Wiener diversity, and Pielou’s evenness indices) did not indicate significant differences between the SPL and EMP areas. Conversely, the abundance-biomass comparison (ABC) method indicated that, on average, the macrobenthic community was moderately disturbed in the SPL and undisturbed in the EMP areas. Multidimensional scaling (MDS) ordination and hierarchical cluster analysis (Bray-Curtis similarity measure) revealed the occurrence of two main benthic assemblages that corresponded to the aquaculture methods. The different rates of water exchange for the two aquaculture practices seem to have contributed to differences in the composition and structure of the benthic communities.

Relearning the ABC: taxonomic changes and abundance/biomass relationships in disturbed benthic communities

For marine macrobenthic communities, a shift from higher biomass dominance with increasing levels of disturbance can be determined by the abundance/biomass comparison (ABC) method. This response results from (i) a shift in the proportions of different phyla present in communities, some phyla having larger-bodied species than others, and (ii) a shift in the relative distributions of abundance and biomass among species within the Annelida (specifically Polychaeta) but not within any of the other major phyla (Mollusca, Crustacea, Echinodermata). The shift within polychaetes reflects the substitution of largerbodied by smaller-bodied species, and not a change in the average size of individuals within a species. In most instances the phyletic changes reinforce the trend in species substitutions within the polychaetes, to produce the overall ABC response, but in some cases they may work against each other. Indications of pollution or disturbance detected by this method should be viewed with caution if the species responsible for the polluted configurations are not polychaetes. These observations provide an aid to interpretation of the ABC plots, especially in some situations where they have been deemed to give a false impression of the disturbance status of a community.

Abundance biomass comparison (ABC method): effects of an estuarine gradient, anoxic/hypoxic events and contaminated sediments

The ABC method for evaluating pollution-induced stress was tested using data from the Chesapeake Bay, Virginia, collected between 1985 and 1989. Three predictions were tested: (1) benthic communities from estuarine transitional regions with salinities near the range of 5 to 8 parts per thousand (horohalinicium) should be classified highly stressed due to major shifts in ionic composition producing physiological stress; (2) benthic communities from regions subjected to summer low dissolved oxygen conditions (anoxia or hypoxia) should be classified as highly stressed after such events; and (3) benthic communities from sediments contaminated with heavy metals and polynuclear aromatic hydrocarbons should be classified as highly stressed. Only partial support for each of these predictions was found and several problems with the ABC method were obvious. A small number of large-sized species, particularly in mesohaline and polyhaline regions of the estuary, greatly affected the analysis. Similar designations of stress could be produced by simply sampling only for these rare, large species. Regions of the estuary considered a priori as highly stressed were sometimes designated as unstressed due to (1) minor shifts in dominance patterns in benthic communities with low absolute numbers of individuals and biomass, e.g. in regions affected by anoxia/hypoxia, and (2) collection of rare, but large species, such as the tubiculous polychaete, Diopatra cuprea, in contaminated sediments. Regions of the estuary considered a priori as unstressed were sometimes designated as highly stressed due to dense recruitment events. Contrary to assumptions of the ABC method, increased sample size (replication) may result in the collection of rare, large-sized individuals in highly stressed communities. Partial dominance curves were applied to the data and (1) removed the effect of biomass dominants in contaminated sediments changing the classification of communities from unstressed to stressed, (2) did not change the stressed classification due to dense recruitment events, and (3) changed the classification of mesohaline and polyhaline communities from unstressed to stressed, even in the absence of low dissolved oxygen events or contaminated sediments. No single method or analysis is likely to produce stress classifications without unacceptable misclassifications. We propose that ecological stress, from any source, is best measured using multiple methods or analyses with different assumptions. The consistency of classification between different approaches would provide the robustness necessary to judge the reliability of a stress classification.

Use of the abundance/biomass method for comparison of fish communities in regulated and unregulated lowland rivers in Belgium

AbstractThe abundance/biomass comparison (ABC) method, proposed by Warwick (1986) for detecting pollution effects on marine macrobenthic communities, was tested on distribution patterns of numbers and biomass among fish species in regulated and non‐regulated lowland rivers in Belgium. The biomass and abundance of the fish populations were determined by electrofishing. The sample sites represent a range of physically disturbed watercourses, from natural meandering to heavily channelized reaches. Sites upstream and downstream from a polluting discharge were also evaluated. The physical habitat and water quality were measured on each site. Our data show a significant correlation between the qualitatively measured physical habitat and an ABC index, calculated from the ABC graph data. A significant correlation was also found between the pollution level and the ABC index. It is concluded that the ABC method is applicable to the assessment of disturbance in fish communities in rivers, and that the method gives information about both pollution and physical disturbance. The ABC method is a useful instrument to assess the status of a fish community before and after river channel works or natural and human induced river restorations.

Analysis of marine macrobenthic community structure in relation to pollution, natural oil seepage and seasonal disturbance in a tropical environment (Trinidad, West Indies)

Macrobenthic species abundances and biomasses were determined at 31 stations from Pointe-a-Pierre to La Brea, Trinidad. This area is subject to chronic natural oil seepage and spillage from oil production activities. Multivariate analysis was used to define those environmental variables which best explained community composition. The deeper sites were impoverished due to the development of anoxia below a pycnocline which formed during the wet season. Abundance/biomass comparison (ABC) plots indicated that macrobenthic communities near an oil refinery were grossly to moderately stressed while those close to the Trinidad Pitch Lake, one of the largest natural oil seeps In the world, were not. Taxonomic aggregation of the species data to family level resulted in little loss of information in the multivariate analyses and apparently Improved the ability of ABC curves to discriminate pollution. Comparisons of the severity of community degradation at these sites using a phylum-level meta-analysis of 'production' were compatible with NE Atlantic data, which augurs well for the more global applicability of this approach. A feature of the Trinidad samples is that they all separate along the upper edge of the meta-analysis 'wedge', due mainly to their higher average proportion of Crustacea relative to Echinodermata and Mollusca. This is explained in terms of the estuarine character of the region, and suggests that the unexplained vertical axis in Warwick & Clarke's (companion article) ordination may be related to natural environmental characteristics

The effect of sewage and natural seasonal disturbances on benthic macrofaunal communities in Fitzroy Bay, Wellington, New Zealand

Benthic macrofauna were sampled on 6 occasions over a 14 month period from Fitzroy Bay, Wellington, New Zealand to assess the effects of an existing sewage effluent discharge on these organisms and to determine natural seasonal fluctuations in community structure within the vicinity of a proposed new ocean outfall. Results of Abundance/Biomass Comparison (ABC), Cluster, and Multi-Dimensional Scaling analyses indicated that only benthic communities within a 500 m radius of the present sewage outfall were affected by the discharge. However, seasonal data indicated that most sites within Fitzroy Bay were disturbed on at least one occasion during the sampling period. The data suggest that ABC analyses should be conducted over several seasons to provide a more accurate assessment of pollution-induced and/or natural physical and biological disturbance.

Comparisons of dominance curves

In studies of community structure, a widely used technique for representing patterns of species abundance (or biomass) in a sample is the dominance curve, in which species are ranked by abundance and the percentage of the total number of individuals belonging to each species is plotted against (log) species rank. Alternatively, these percentages are cumulated, as in “ k-dominance” curves, or separate k-dominance curves for abundance and biomass are superimposed, giving “abundance-biomass comparison” (ABC) curves. When such curves are replicated for samples from a number of sites, times or treatments, questions of statistical significance of apparent differences arise. A framework for such tests is described, and illustrated with data from the IOC/GEEP Bermuda Workshop and other studies of the effects of pollutants on benthic communities. Also discussed is an approximately linearising transformation for the y axis of a k-dominance plot, designed to improve clarity of presentation. In addition, a new descriptive tool is proposed for displaying “partial dominance” patterns in community data and it is suggested that this may mitigate a recent criticism of Warwick's ABC method, viz., its overdependence on the single most dominant species.

Detection of pollution effects on marine macrobenthos: further evaluation of the species abundance/biomass method

Further empirical data are presented to evaluate the method of detecting pollution-induced disturbance in marine benthic communities by a comparison of the distribution of numbers of individuals among species with the distribution of biomass among species. A suggested abbreviated name for the technique is the ABC method (abundance biomass comparison). Application of the technique to new data shows that it is a sensitive indicator of natural physical and biological disturbance as well as pollution-induced disturbance over both spatial and temporal scales. Changes in the configuration of ABC plots during ecological succession are the reverse of those resulting from increased pollution levels. The technique should also be applicable to intertidal sediments, where physical disturbance of the sediment by waves does not appear to preclude its utility.