Richard M. Warwick

Plymouth Marine Laboratory | PML · Marine Life Support Systems Research Area

Perfectly circular patches bare of vegetation in otherwise continuous swards of seagrass, and perfect circles of seagrass with lush fringes of shoots on the outer margins but with virtually bare centres, have both attracted popular attention as ‘fairy circles’ or ‘fairy rings’ in view of the folklore surrounding the supernatural origins of their te...

Research Infrastructures (RIs) are facilities, resources and services used by the scientific community to conduct research and foster innovation. LifeWatch ERIC has developed various virtual research environments, which include many virtual laboratories (vLabs) offering high computational capacity and comprehensive collaborative platforms that supp...

Abstract

Attributes of the community level of biological organization reflect integrated environmental conditions over a period of time, and can be used to detect and monitor the effects of environmental pollution. Methods of data analysis include univariate indices, graphical distributional techniques and multivariate methods, the latter being particularly...

Nematodes are small multicellular, thread-like organisms, inhabiting almost all conceivable environments; among these, some 25 % are free-living marine forms with a population density of (1-12) x 10(6) inds m(-2) in seabed sediment, reaching maximum values in muddy estuaries and salt marshes. A large quantity of carbon from the salt marsh plants en...

Statutory monitoring of the fauna of the ‘mudflats and sandflats not covered by seawater at low tide’ biotope complex on St Martin’s Flats, a part of the Isles of Scilly Complex Special Area of Conservation, was undertaken in 2000, 2004 and 2009. The targets set by Natural England for “characteristic biotopes” were that “composite species, abundanc...

Species size distributions for metazoan benthic invertebrates conform to the highly conservative bimodal pattern, regardless of the sieve mesh sizes or numbers of sieves used in their extraction. This pattern is not an artefact of sampling a size continuum as suggested by computer simulations using just 2 fixed mesh sizes in Bett (2013; Mar Ecol Pr...

Analysis of benthic macroinvertebrate samples at a higher taxonomic level than species, e.g. family, potentially provides a more cost-effective protocol for environmental impact assessments and monitoring as it requires less time, funds and taxonomic expertise. Using the AMBI database, species ecological group scores are shown to be coherent within...

Mangroves are highly productive environments that play important ecological and socioeconomic roles; however, they have been impacted to different degrees in most countries worldwide. The knowledge of which organisms inhabit this environment and their ecological interactions is the first step towards its conservation. The natural variability of env...

Benthic biomass size spectra (BSS) and normalized biomass size spectra were constructed, and benthic secondary production was estimated by a size spectrum equation in the shallow waters in the East China Sea, ranging latitudinally from 40°N to 29°N. The BSS patterns were bimodal, two biomass peaks corresponding to meiofauna and macrofauna, respecti...

Meiofaunal organisms are mobile multicellular animals that are smaller than macrofauna and larger than microfauna. The size boundaries of meiofauna are generally based on the standardised mesh apertures of sieves with 500 μm (or 1000 μm) as upper and 63 μm (or 42 μm) as lower limits. Meiofauna are ubiquitous, inhabiting most marine substrata, often...

Establishment of a benchmark against which deleterious changes to an estuary can be evaluated requires validating that it has not been subjected to detrimental anthropogenic perturbations and then identifying the biological features which are indicative of a pristine condition and can thus be employed as indicators for detecting and monitoring depa...

Initially described in 2000, AZTI's Marine Biotic Index (AMBI) aims to assess alterations in communities of soft-bottom marine benthic macroinvertebrates caused by anthropogenic impacts. Although it was designed to be used in European estuaries and coasts this index, based on Pearson and Rosenberg's model of responses to organic enrichment, is bein...

The present study examines traditional paradigms regarding the differences between faunas in estuaries vs coastal waters. The ecological characteristics of the free-living nematode faunas of nearshore, subtidal sediments in downstream and upstream areas of the large, microtidal Swan River Estuary are compared with those similarly recorded seasonall...

Descriptions of 10 new species of free-living aquatic nematodes are presented. Four of the new species belong to the Axonolaimidae, i.e. Ascolaimus australis, Parascolaimus brevisetus, Odontophora serrata and Parodontophora aurata. The remaining six species belong to the Desmodoridae, i.e. Bolbonema spiralis, Onyx cephalispiculus, O. potteri, Eubos...

This study tested the hypothesis that, during recent years, the benthic macroinvertebrate fauna of the large basin of the Swan-Canning Estuary has changed in ways consistent with deteriorating environmental conditions in that estuary. Between 1986/7 and 2003/4, the compositions of that fauna altered markedly at the species and even family levels. T...

The results of manipulating the input data to AMBI are explored using various transformations of numerical species abundance (NAMBI), biomass (BAMBI) and production (PAMBI) from a variety of stations on the NE Atlantic shelf at which the pollution/disturbance status is known. There is a close agreement between the proportions of species in the five...

An artificial channel was opened in 1994 between the microtidal Peel-Harvey Estuary and the Indian Ocean to increase tidal exchange and thus ameliorate the problems of eutrophication. Although this greatly reduced macroalgal and cyanobacterial growths and the amount of particulate organic matter, our data indicate that, contrary to managerial expec...

The search for simple and effective descriptors of biological ecosystem components is a major challenge of monitoring the health of transitional waters. The recent development of rapid environmental assessment techniques provides additional tools that can assist the monitoring and evaluation of the aquatic environment: (a) the taxonomic sufficiency...

This study has determined the ways in which the density, number of species, species composition and trophic structure of free-living nematode assemblages in the subtidal waters of a large southern hemisphere microtidal estuary change spatially and seasonally, and has explored whether those four biotic characteristics are related to certain environm...

Simpson's index may be defined in different ways, but the original and simplest is that it is the probability that two individuals drawn at random from an assemblage will belong to the same species. As such it is a measure of dominance, and for a highly dominated (i.e., highly uneven) assemblage the probability of drawing two individuals from the s...

Taxonomic relatedness of the individuals or species in a sample is the key concept on which taxonomic diversity and distinctness measures of biodiversity are based. It is well known that in impacted assemblages of organisms the taxonomic spread of species is reduced, and in extreme cases they may be sibling species belonging to the same genus, or a...

If the number of animal species is to be used as a measure of ‘biodiversity’, or if distributions of species among taxa of higher rank are to be used to infer evolutionary or ecological patterns, then we need to know whether animal phyla are consistently subdivided in such a way that each species represents an equal division of life's diversity. It...

Somerfield, P. J., Clarke, K. R., Warwick, R. M., and Dulvy, N. K. 2008. Average functional distinctness as a measure of the composition of assemblages. – ICES Journal of Marine Science, 65: 1462–1468. Indices are used to quantify change in the environment by reducing aspects of environmental complexity to numbers. Biodiversity indices are typicall...

The objective of this work was to undertake a statistical analysis of benthic data from around fish farms, held by SEPA, to determine whether analyses based on a single reduced species list can adequately reflect variation and stress in the whole benthic community, what that list should be, and how practical it would be to employ it (i.e. does it r...

Ecologists have long struggled to predict features of ecological systems, such as the numbers and diversity of organisms. The wide range of body sizes in ecological communities, from tiny microbes to large animals and plants, is emerging as the key to prediction. Based on the relationship between body size and features such as biological rates, the...

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Benthic infauna live in a three-dimensional world, and patterns of horizontal distribution may vary with depth in the sediment, as may the mechanisms that determine those patterns. This study examines how horizontal spatial structure varies with depth in a semi-exposed coarse-sand flat adjacent to St Martin's, one of the Isles of Scilly, UK. Nemato...

Many biological data sets, from field observations and manipulative experiments, involve crossed factor designs, analysed in a univariate context by higher-way analyses of variance which partition out ‘main’ and ‘interaction’ effects. Indeed, tests for significance of interactions among factors, such as differing Before–After responses at Control a...

This study provides a holistic perspective on the ecological effects of dredged material disposal, both intertidally and subtidally. A number of numerical techniques (univariate, distributional, multivariate and meta-analysis) were used to assess impacts at 18 different disposal sites. The analyses revealed that ecological effects associated with d...

Phylum-level meta-analysis was applied to 192 samples from a variety of dredgings disposal and relocation sites around the coast of England and Wales. No consistent relationship was found between the disturbance status of macrobenthic communities within disposal sites and the nature or amount of dredgings disposed. Differences between samples withi...

The aim of this study was to determine if marine species diversity was influenced by geographical location and whether it was higher at lower latitudes. Artificial collectors (made of nylon pan scourers) were employed as a standard substratum for the colonisation of marine invertebrates inhabiting subtidal (12 to 15 m) hard, rocky bottom substrata....

Mankind needs to use the resources and opportunities offered by the marine environment while protecting ecological processes and systems. This is the foundation for sustainable development, which can only be achieved by adopting an appropriate management approach. Whether internationally or at a regional scale, successful management of marine ecosy...

To assess potential risks of human visitation to ecological communities, the immediate effects of human trampling were investigated experimentally on small invertebrates inhabiting mid-upper intertidal hard bottoms covered by algae. Two different experimental intensities of trampling (60 and 120 footsteps) and controls (with no trampling) were appl...

In diversity research, the use of survey data appears to have declined in favour of experimental or modeling approaches because direct relationships are difficult to demonstrate. Here we show that use of field data can yield information concerning the mechanisms governing diversity. First, we establish that tintinnids display a global latitudinal p...

A combination of enclosure nutrient enrichment experiments and historical data analysis was used to identify the factors controlling seasonal dynamics and competition of the phytoplankton community in the Curonian lagoon (Southeast Baltic Sea). Experiments using different nutrient (N, P and Si) manipulations were performed in 10-l enclosures for 48...

This volume presents selected contributions given to the 38th European Marine Biology Symposium, held in Aveiro, Portugal, in September 2003. Understanding the functioning of Marine Ecosystems is the first step to measure and predict the influence of Man, and to find solutions for the enormous array of problems we face today. This volume is organi...

This study has determined the ways in which the characteristics of the nematode assemblages in nearshore marine waters along the microtidal lower west coast of Australia are influenced by habitat type, time of year and shore-perpendicular zones. The habitat types (1, 2 and 6), which had previously been identified on the basis of a suite of enduring...

The death assemblage of molluscs (gastropods and bivalves) from the sandy beach at Harlyn Bay, north Cornwall is shown to be fully representative of the biodiversity of the regional species pool from all habitat types. The biodiversity measures used are average taxonomic distinctness (Δ+, the average degree to which species in an assemblage are rel...

ABSTRAC7: -To determine the effects of natural and anthropogenic variables on the benthic harpacticoid copepod assemblages of the Bohai Sea, China, samples were collected on two occasions from an extensive grid of 20 stations. Differences among stations between sampling periods, although significant, were a consequence of small changes in abundance...

We test the hypothesis that the biodiversity of the death assemblage of shelled molluscs (gastropods and bivalves) on a single sandflat is representative of the biodiversity of the regional living fauna from the complete spectrum of habitat types, and can therefore be used as a surrogate for the purposes of rapid biodiversity assessment. Two biodiv...

The phylum-level meta-analysis approach has been proposed as a way of comparing geographically different areas along a common scale of disturbance. However, the training data set which establishes the scale of disturbance and all subsequent studies using the approach have been exposed to some sort of organic or inorganic pollution. Using macrobenth...

Freeliving marine nematodes were sampled on two occasions from an extensive grid of 20 stations in the Bohai Sea and its approaches. Differences within stations between sampling periods were small, resulting from small changes in abundance of dominant species. Differences between stations were significant, and were used to cluster stations into gro...

Over 2 years, experiments were conducted to compare the effects of sediment disturbance by different bioturbating, macrofaunal organisms on the diversity and structure of the associated infaunal community. The four species investigated were the bivalves Nuculoma tenuis (Montagu, 1808) and Abra alba (Wood, 1802), the heart urchin Brissopsis lyrifera...

Taxonomic distinctness is a univariate (bio)diversity index which, in its simplest form, calculates the average 'distance' between all pairs of species in a community sample, where this distance is defined as the path length through a standard Linnean or phylogenetic tree connecting these species. It has some appealing properties: it attempts to ca...

Summary •The objectives of this paper are to test the performance of the taxonomic distinctness index, +, in a number of environmental impact scenarios, to examine its relationship with functional diversity and to examine the influence of habitat type and diversity on the index. •The index was applied to data on free-living marine nematodes from t...

Summary •For biological community data (species-by-sample abundance matrices), Warwick & Clarke (1995) defined two biodiversity indices, capturing the structure not only of the distribution of abundances amongst species but also the taxonomic relatedness of the species in each sample. The first index, taxonomic diversity (), can be thought of as t...

In multivariate analyses of the effects of both natural and anthropogenic environmental variability on community composition, many species are interchangeable in the way that they characterise the samples, giving rise to the concept of structural redundancy in community composition. Here, we develop a method of quantifying the extent of this redund...

This report focuses on the Environment Agency’s primary requirement “to assess the present biological status of the Carnon Catchment and the Fal Estuary and the significance of the minewater discharges on the floral and faunal communities in the Carnon River and Fal Estuary”. The flora and fauna of the Carnon River itself are greatly impoverished a...

The influence of the large suspension feeding horse mussel Atrina zelandica Gray on meiobenthic diversity and community structure has been studied at two sites in New Zealand where Atrina beds form discrete patches. Community attributes inside (IN samples) and outside the beds (OUT samples) in the bare sediment have been compared. At both a shelter...

Plots of the number of species against body size for a wide range of undisturbed macrobenthic assemblages on the European continental shelf have an approximately lognormal distribution, i.e. there are more species of intermediate size than of either larger or smaller sizes. The total abundance of all macrobenthic species combined also peaks at an i...

Studies of the interplay of immigration, emigration and extinction in shaping the fauna of islands (McArthur & Wilson, 1967) have influenced the terrestrial ecologists view of the creation and maintenance of diversity. Although in the deep ocean, hydrothermal vents have been the subject of a number of biogeographic studies (Tunnicliffe, 1991), ther...

A global study of latitudinal gradients in biodiversity of marine shallow-water, motile epifauna of hard substrata has been initiated by Plymouth Marine Laboratory and the International Association of Meiobenthologists. It is based on the use of artificial substratum units (ASUs) consisting of four pan-scourers and emphasizes the standardization of...

Patterns in community structure of macrofauna (Day grab samples), nematodes (Craib core samples and subsamples from Day grabs) and copepods (Craib core samples) along a transect through a dredgings disposal site in Liverpool Bay, UK, are compared, and related to a range of environmental measurements. Disposal of dredged material at the site has dif...

A comparative mesocosm experiment was carried out to determine the effects of natural foods of different quality and quantity on the structure of natural meiobenthic communities collected in undisturbed sediment from the polluted Westerschelde and the comparatively undisturbed Gironde estuaries. Nematode communities are more diverse and species ric...

In preliminary microcosm experiments we have been able to demonstrate a clear differential response of meiobenthic assemblages to zinc, copper and cadmium contamination. Sediment and natural meiobenthic communities were collected from two estuaries, the Lynher (mud with a high organic content) and Exe (sand with a low organic content). The sediment...

Habitat architecture has two major components, size and structural variety. Both these attributes are incorporated in measurements of fractal dimensions which are essentially an expression of habitat size in relation to the scale of measurement. Therefore, the fractal dimensions of a habitat, coupled with energy requirements, may be one explanation...

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 shif...

The large, sparse arrays of species counts arising in both field and experimental community studies do not lend themselves to standard statistical tests based on multivariate normality. Instead, a valid and more revealing approach uses informal display methods, such as clustering or multi-dimensional scaling ordination (MDS), based on a biologicall...

The Fal estuary system, southwest England, is an ideal site for a natural experiment on the effects of long-term contamination by heavy metals on intertidal mudflat meiofauna communities. Five creeks were chosen in which sediment concentrations of heavy metals differed by orders of magnitude, namely Restronguet (mean Cu concentration 2532 mug g-1),...

A measure of the complexity of a habitat independent of habitat type has long been required by benthic ecologists, particularly when comparisons between habitats or substrates need to be made and related to parameters of community structure. Using marine algae from the Isles of Scilly, UK, and their associated epifaunal communities as a testbed we...

Intertidal and shallow water reef-corals usually exhibit a regular pattern of change in community structure with increasing water depth. A statistic is developed, the Index of Multivariate Seriation (IMS), which measures the degree to which this community change conforms to a linear sequence. Seriation broke down, and the IMS was reduced, when a co...

An increase in variability between samples collected from impacted vs. control areas is described for four different types of marine communities: meiobcnthos subjected to organic enrichment, macrobenthos in the vicinity of the Ekofisk oil-field, reef-corals following the 1982–3 El Niño and fish on coral reefs which are subjected to mining. In each...

A new species of mouthless and gutless free-living marine nematode, Astomonema southwardorum sp. nov., the dominant species from a methane seep pockmark in the North Sea, is described and illustrated. The new species is distinguished by its combination of short cephalic and cervical setae, with the latter being sparsely and irregularly distributed,...

A multivariate method of comparing the severity of disturbance to subtidal macrobenthic communities on a common scale is described. Data on species abundances and biomasses from a variety of stations on the NE Atlantic shelf at which the pollution/disturbance status is known have been aggregated to phylum level and the abundance and biomass data me...

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 w...

During the Bremerhaven Workshop, the meiofaunal communities along 2 supposed North Sea pollution gradients, one at a drilling site off the Dutch coast and the other across the German Bight, were analysed by a variety of univariate and multivariate techniques and the changes on community structure related to a suite of measured environmental variabl...

A comparison of the community structure of the macrobenthos and meiobenthos at six stations in Hamilton Harbour, Bermuda showed that the two components were affected differently by environmental disturbance. Univariate statistical analysis of the macrofauna species data gave clear indications of disturbance at two stations, which did not relate to...