Richard Warwick

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

K. Robert Clarke is one of the most highly regarded and highly cited scientists in the field of ecology. Over the past 45+ years, He has inspired and empowered ecological researchers all across the globe by developing novel statistical methods, creating user-friendly PRIMER software, and presenting generous, spirited, personalised workshops in mult...

Size-frequency analysis of the echinoid Echinocyamus pusillus from six offshore areas in the southern North Sea and eastern English Channel reveal five distinct cohorts, suggesting a lifespan of five years. In all six individual areas one or more year-groups are absent, due to the unsuccessful recruitment of planktonic larvae to the seabed in some...

This paper compares the diversity, distribution and trophic composition of the nematode assemblages in the intertidal sediments of the macrotidal Exe Estuary (UK) and the shallow subtidal sediments of the microtidal Swan Estuary (Australia), the latter having been subjected to long-standing anthropogenic disturbance. Data from studies partially des...

This study describes the ecology of mesozooplankton in the shallows of the large central basin area of the Swan-Canning Estuary on the microtidal lower west coast of Australia during the mid-1980s when, as in most other south-western Australian estuaries, it was mesotrophic. As the vast majority of species reproduce within the estuary and there is...

Research Infrastructures (RIs) are facilities, resources and services used by scientists to perform research and support innovation. A number of EU research infrastructures [e.g. e-Science and Technology European Infrastructure for Biodiversity and Ecosystem Research (LifeWatch) European Research Iinfrastructures Consortium (ERIC); The European lif...

Mesozooplankton was sampled seasonally in a large microtidal estuary (Peel-Harvey) suffering from massive macroalgal growths and cyanobacterial blooms. Comparisons with other estuaries indicate that eutrophication led to copepod abundance declining and macroalgal-associated species increasing. Mesozooplankton species are almost exclusively autochth...

Not all estuaries are equally susceptible to anthropogenic perturbation. Microtidal estuaries with long residence times are intrinsically less robust than well-flushed macrotidal estuaries, facilitating the accumulation of contaminants. This promotes development of blooms of non-toxic and toxic phytoplankton, and hypoxia and anoxia may occur in dee...

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...

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...

A 26 year time series of monthly samples from the water intake of a power station has been used to analyse the abundance, number of species and composition of the mysid and caridean decapod fauna in the inner Bristol Channel. During this period, annual water temperatures, salinities and the North Atlantic Oscillation Index (NAOI) in winter did not...

Although early microscopists first described meiobenthic-sized animals from fresh water, it is widely acknowledged that studies of the ecology of freshwater meiofauna have taken longer to emerge as an independent discipline than those of their marine counterpart. The early literature on this freshwater fauna used terms relating to habitat rather th...

The species composition of fish communities in 15 microtidal estuaries in south-western Australia, ranging from permanently-open to normally-closed, is shown to be related to the geomorphological and hydrological regimes and not to environmental condition. This study then explored the effectiveness of using qualitative taxonomic distinctness and AB...

Tidal range is a master factor governing the differences in physico-chemical and biological characteristics between microtidal (<2 m) and macrotidal (>2 m) estuaries, which, for convenience, thus include mesotidal estuaries (2–4 m). Microtidal estuaries differ from macrotidal estuaries in geomorphology, tidal water movements, salinity regimes, resi...

Runoff from an extreme storm on 22 March 2010 led, during the next three months, to the formation of a pronounced halocline and underlying hypoxia in the upper reaches of the microtidal Swan-Canning Estuary. Benthic macroinvertebrates were sampled between January 2010 and October 2011 at five locations along 10 km of this region. By mid-April, the...

The characteristics of the biota and fisheries of estuaries are considered in the context of a contemporary definition that recognizes the physico-chemical features of the different estuary types found worldwide, i.e. macrotidal v. microtidal and permanently-open v. seasonally-open v. normally-closed. The ways in which fishes use estuaries, feed an...

Runoff from an extreme storm on 22 March 2010 led, during the next three months, to the formation of a pronounced halocline and underlying hypoxia in the upper reaches of the microtidal Swan-Canning Estuary, Western Australia. Benthic macroinvertebrates were sampled between January 2010 and October 2011 at five locations along 10 km of this region...

Point sampling of soft-sediment macrofauna provided a regional-scale analysis of species composition, diversity, and demographic distributions in the northern Bering Sea (61°0′–65°30′N Lat) in spring 2006. Taxonomic differences distinguished subregions north and south of St. Lawrence Island (P<0.1%). High compositional variability occurred within a...

The severity of the physical regime in the hypertidal Severn Estuary and Bristol Channel decreases in intensity in the seaward direction. As a result, the diversity of benthic macrofaunal species is very low in the Estuary and Inner Channel, but is still relatively low in the Outer Channel compared with more benign conditions elsewhere in the UK. N...

We assessed the development of the exploited fish community inside and around the Columbretes Islands Marine Reserve (CIMR), a marine protected area (MPA), 8 to 16 yr after fishing ceased in the reserve. Sampling was by annual lobster trammel net fishing, an experimental tech- nique used inside the CIMR, and on-board commercial operations in adjace...

Meiobenthic samples were collected by two different methods from the microtidal coralline sand beach at Gosier, Guadeloupe, West Indies: (I) vertical cores and (2) the Karaman/Chappuis (KC) technique of digging a hole and filtering the seepage water from the bottom. Nematode species diversity was unaffected by the sampling method, but nematode spec...

Reliable descriptions of the status of offshore seabed habitats usually require substantial investment in field data collection and sample analysis. While assessment of, for example, biogenic reef habitat can often include simple physical parameters (e.g. spatial extent), comparative measures for soft sediment habitats generally rely on the distrib...

The meiobenthos are regarded as the first metazoans to appear on earth This paper considers some aspects of their role in the marine ecosystem over evolutionary time. It is speculatively suggested that they have had a profound influence on many structural and functional attributes of the marine ecosystem as we see it today, both in the benthic and...

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...

Recently a new index has been proposed for the evaluation of biodiversity: taxonomic distinctness. One of the positive features of this index is that it is neither sampling-effort nor sample-size dependent. Until now, its application has been limited to the assessment of zoobenthos and fish biodiversity. The main objective of this paper was to tes...

Many recent studies have shown that very little information is lost by working at a taxonomic level higher than species. This implies a functional coherence of species within each higher taxon. Indeed, there are theoretical reasons, and some empirical evidence, for supposing that community responses to human perturbations may be more easily detecte...

It has been suggested that the scaling relationships of many features of the physical environment and biological traits are fractal-like, but for the marine benthic infauna certain aspects of the environment clearly are not. These include temporal features such as the cycles of annual climate, primary production and tides, and also some spatial fea...

Summary • Data on soft-sediment macrobenthos from the Norwegian continental shelf (56–71°N) was used to examine the use of average taxonomic distinctness (Δ+, a measure of the average degree to which species are related to each other) as a diversity measure. • Δ+ for all taxa combined decreased with both latitude and depth. In contrast Δ+ for annel...

While organic matter in sediments is an important source of food for benthic fauna, an overabundance can cause reductions in species richness, abundance, and biomass due to oxygen depletion and buildup of toxic by-products (ammonia and sulphide) associated with the breakdown of these materials. Moreover, increasing organic content of sediment is of...

Considering the long history of oil extraction and the numerous platforms that exist in the southern Gulf of Mexico, a regional approach has been used to investigate the impact of oil-related activities on the macrobenthic community. The objective was to determine the effect of oil-related activity in a region known to have a highly variable benthi...

Hitherto only three turbellarian species have been recorded from the Isles of Scilly, Oligocladus sanguinolentus (Quatrefages 1845), Prostheceraeus vittatus (Montagu 1815) and Leptoplana tremellaris (Müller 1773). A taxonomic collection survey in May 2002 revealed 67 species of Turbellaria. Among these, 46 species are known to science and could be...

The workshop brought together international scientists and coastal managers in related fields including members of the UNESCO/IOC Ad-Hoc Benthic Indicator Group, the Benthic Ecology Working Group of the International Council for the Exploration of the Sea (ICES-BEWG), the LaguNET (Italian Network on Transitional Systems), the APAT (Italian Agency f...

Marine biodiversity and its distribution in the New Zealand region were determined using historical data for an appropriate indicator taxon, the Bryozoa. Bryozoans were identified as belonging to three communities, termed Intertidal/Shelf/Slope (ISS) and Deep-Sea 1 and 2 (DS1 and DS2). Biodiversity was assessed using measures based on relatedness o...

The overall aim of this work was to explore a redefinition of the nature of environmental change in production areas, both in the vicinity of installations and in the further field, which may have implications for the requirements (such as reducing replication effort) for environmental monitoring. The specific objectives were: 1. Use the UKOOA data...

The influence of large-scale natural disturbance from winter storms (‘northers’) and river runoff on the macrobenthic community structure of the southern Gulf of Mexico was investigated in both carbonate and transitional carbonate–terrigenous sedimentary environments. Samples of the infauna were obtained in three seasons from 13 stations from two 2...

Summary • Despite numerous studies that have investigated the effects of physical disturbance on marine benthic communities, deducing the ecological significance of such events has been hampered by the specificity of individual studies. Less stable habitats (coarse, clean sands) are thought to recover more quickly than stable (muddy sands and mud)...

The peer-review system is overloaded. This causes problems for reviewers and editors. The focus of this Theme Section (TS) is misuse of the peer-review system by repeated resubmission of unchanged manuscripts (mss). A number of editors and experienced reviewers were invited for comments. Most contributors have seen examples of authors resubmitting...

The composition of meiobenthic and macrobenthic communities between different intertidal reef-flat pools on Rocas Atoll (South Atlantic) was compared, and related to properties of the carbonate sediments and patterns of reef growth. Both univariate and multivariate statistical analyses showed that the reef height and size influenced the properties...

Physical disturbance in soft sediment habitats disrupts the sediment structure and can lead to the death or emigration of resident biota. Current methods used to quantify the response of benthic assemblages to physical disturbance are time consuming and expensive, requiring the analysis of a time series of samples to ascertain the time taken for a...

A hierarchical diversity index--taxonomic distinctness index delta+, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes. The result showed that the Bohai Bay and other coastal sampling sites might be affected by oil and gas production and other anthro...

A 17-year monitoring programme of reef flats at Ko Phuket, Thailand afforded an opportunity to evaluate both univariate and multivariate measures of environmental stress in an assessment of change on coral reef ecosystems. The sites at Ko Phuket suffered the effects of dredging in 1986-1987 and then anomalously low sea levels in 1997-1998 as a resu...

Abundances of macrobenthic species were monitored twice yearly (March and Septem-ber) at 6 locations in Tees Bay, UK, between 1973 and 1996, and once yearly at 4 stations in the outer Tees estuary and 7 stations in the inner estuary between 1980 and 1999. In the Bay, multivariate analysis revealed a serial pattern of community change over years for...

Thirteen species, or putative species, of freeliving nematodes are recorded from a variety of habitats in the hypersaline Salton Sea, the largest inland lake in California. This doubles the number of species of multicellular invertebrates known to occur in the lake. All species are referable to known marine genera, and are regarded as having a mari...

A further biodiversity index is proposed, based on taxonomic (or phylogenetic) relatedness of species, namely the 'variation in taxonomic distinctness' (VarTD, Lambda (+)) between every pair of species recorded in a study. It complements the previously defined 'average taxonomic distinctness' (AvTD, Delta (+)), which is the mean path length through...

The intertidal invertebrate macrofauna of five creeks in the Fal estuarine system, Cornwall, UK, is compared with data from 40 locations in six other estuaries in south-west Britain. Multivariate analysis shows that the community composition in the Fal is distinct from all the other estuaries. The differences are principally due to the absence of t...

In contrast to terrestrial biodiversity, marine biodiversity has a number of distinctive features that suggest that a broader strategy for its conservation might be more appropriate than a local reserve-based one. Traditional diversity measures based on species richness and evenness often have disadvantages in the assessment of biodiversity change...

Species of the marine nematode genus Pontonema have been found to dominate the macrobenthos under abnormally high conditions of particulate organic enrichment. Populations from organically enriched habitats in six localities (Kiel fjord, Germany; the Garroch Head sewage-sludge dump ground in the Firth of Clyde, Scotland; Cornelian Bay, N.E. England...

Rocas, the only atoll in the South Atlantic, is located 266 km off the northeast Brazilian coast. Spatial patterns in community structure of meiofauna, particularly nematodes, and macrofauna were examined along a transect through the sediment path from windward to leeward of the Rocas Atoll sand flat. Differences in benthic community structure betw...

The objective of this study was to test the hypotheses that (1) assemblages of the same broad group of animals respond in a differential way to different classes of disturbance (i.e. there is not simply a generalised stress response), and that (2) the nature of the response differs according to the environmental conditions that the assemblages norm...

Topographically controlled fronts are small-scale phenomena caused by the interaction between currents and complex reef topography, resulting in zones of convergence and eddies where debris and organisms are accumulated. Rocas is the only atoll in the South Atlantic (3 degrees 51'S, 33 degrees 49'W) and it is constructed predominantly by coralline...

A microcosm experiment was conducted to investigate the effects of continuous and episodic biological disturbance by Carcinus maenas on estuarine nematode assemblages from sand and mud for a period of 57 days. Univariate methods of data evaluation failed to reveal major changes in community structure. Distributional techniques (dominance curves) we...

Rocas is the only atoll of the South Atlantic and it is built almost exclusively by coralline red algae, vermetid gastropods and encrusting foraminiferans. Patterns in the community structure of meiofauna and macrofauna, particularly nematodes and polychaetes, at Rocas Atoll, north-east Brazil, are determined and compared for different habitats: su...

The objectives of this paper are to test the performance of the taxonomic distinctness index, δ+, 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 the coasts...

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 (δ), can be thought of as the averag...

The environmental management of anthropogenic inputs of organic materials to the sea requires a knowledge of the effects of different intensities and frequencies of input in relation to the nature of the receiving assemblages of organisms, A microcosm experiment was carried out to study whether the response of nematode communities to 3 different qu...

A microcosm experiment was carried out to evaluate the effects of continuous and spasmodic physical disturbance of differing frequency on the structure of nematode communities of intertidal sand and mud. There was a marked, characteristic change in abundance and diversity for both sediment types. In the sand microcosms, the majority of univariate m...

Short term fluctuations in physical parameters are particularly important in determining faunal diversity of intertidal beaches, and the main objective of this paper is to describe the situation on the Caribbean island of Guadeloupe with respect to the meiobenthos of this habitat. A meiofaunal inventory was established for 23 beaches in 1979 and si...

In most subtidal soft-sediment faunal assemblages there is a trough in the species size distribution separating the macrofauna and meiofauna. To examine the hypothesis that this may be maintained by the avoidance of competition between macrofaunal adults and settling larvae, samples were taken from around Svalbard, an area where most macrofaunal sp...

We demonstrate a continuous decrease in the taxonomic distinctness of a marine assemblage along a gradient of increasing environmental contamination, in a situation where species diversity remains constant. Two indices have been employed, Delta and Delta*, the first being a taxonomic diversity index empirically related to Shannon species diversity...

Meiofaunal samples have been collected from 15 sites in intertidal beaches in Moorea, and analysed for higher taxa and nematode species. The composition of higher taxa is related to overall meiofaunal abundance and to the sediment grain-size; at most stations harpacticoid copepods are more abundant than nematodes. There is a significant negative co...

Eutrophication in the Palude della Rosa, in the Lagoon of Venice, results from agricultural runoff giving rise to a seasonal cycle of proliferation and subsequent decomposition of the green algaUlva rigidaduring the summer months, with a dramatic fall in oxygen levels. A survey of the meiofauna at 42 stations in the Palude in December 1991 showed t...

Southwest Cornwall, UK, has a long history of metal mining which has resulted in the establishment, over historical time, of a marked gradient in heavy metal concentrations in the sediments of creeks in the Fal Estuary system. In 1991 Wheal Jane, the last tin mine in the Carnon Valley, closed and the mine workings and Tailings Dam filled with acidi...

Coral mining takes place on shallow reef flats at a number of localities in the Maldives, but not on the adjacent deeper reef slopes. A semi-quantitative census method for fish species abundance and biomass is described. Fish community structure is compared on mined and non-mined reef flats and their adjacent slopes using a variety of univariate, g...

(1) A winter survey of seven species of wading birds (Charadrii) at forty intertidal sites in six estuaries in south-west England was made to identify the variables that determined the variation in bird densities between the sites and to develop a method for predicting bird densities should a tidal power barrage be built on the Severn estuary. (2)...

(1) A survey of intertidal macrobenthic invertebrates at forty sites in SIX estuaries in SW Britain was undertaken to identify the key environmental variables which determine the composition of these communities and to provide a prediction of conditions in the Severn estuary should a barrage for the generation of tidal power be built. (2) Multi-dim...

Statistical methods for analysing changes in community structure fall under the three general headings of univariate, graphical/distributional and multivariate. These methods are applied to a variety of benthic community data (macrobenthos, meiobenthos, corals, demersal fish), from a variety of localities (intertidal/subtidal, temperate/tropical) a...

Thirty one species of marine gastrotrich are listed from 13 sand-beach and tidal flat sites on the Isles of Scilly, UK, and their distribution is described. Several species occurred at higher levels on the shore than they do on the mainland. Considered in relation to coastal exposure, the species richness for the chaetonotids and total gastrotrichs...

In a survey of ten sites in the Tamar estuary in January 1984, spatial variability in the species composition and structure of nematode and copepod species assemblages was greater between sites over a range of 1–3 km than between replicates at the same site. Two aspects of meiofauna community structure were studied: (1) the multivariate information...