Are semi-aquatic bugs (Heteroptera: Nepomorpha) indicators of hydrological stability of permanent ponds?

The composition of semi-aquatic bug communities from eight permanent ponds from southern Transylvania was investigated between 2001 and 2004. Three of the ponds were sampled repeatedly throughout the active period of the year, while the other five were sampled only once. Microvelia reticulata (Burmeister, 1835) and Gerris argentatus Schummel, 1832 were the dominant species from the thoroughly investigated habitats. Statistical analysis proved that each of the sampled species has specific habitat preferences in relation to the modifications of the hydrological regime of the ponds (reflected by the modifications of open water areas, station sizes, and percentages of vegetation coverage). The results, obtained from the three habitats investigated throughout the active period, were confirmed by the samples taken from the other five habitats opening the discussion about the use of semi-aquatic bug communities as bioindicators of the hydrological regime for permanent ponds.     

The effects of an abandoned roast yard on the fish and macroinvertebrate communities of surrounding beaver ponds

Recently formed beaver-ponds surrounding an abandoned copper-nickel ore roast yard near Sudbury, Ontario, Canada, were influenced by highly acidic and heavy-metal contaminated effluent. Fish, including Culaea inconstans, Phoxinus neogaeus, Phoxinus eos, and Pimephales promelas, were found in the ponds upstream of the roast yard only. Macroinvertebrate taxon richness and diversity were greater in the upstream ponds than in the downstream ponds. Acid intolerant taxa, including Mollusca and Hyalella azteca, were found upstream only; acid tolerant taxa, including Enallagma and Ischnura (Odonata: Coenagrionidae) were found in the downstream ponds. One taxon, a species of Chironomus, was especially tolerant of both acid and metal stresses, and was the only invertebrate taxon found in the pond located directly on the roast yard itself. We conclude that long-abandoned mining and refining sites can continue to have a marked effect on aquatic communities.     

Hydroperiod,predators and the distribution of physid snails across the freshwater habitat gradient

1. Studies of species distributions across environmental gradients further our understanding of mechanisms regulating species diversity at the landscape scale. For some freshwater taxa the habitat gradient from small, shallow and temporary ponds to large, deep and permanent lakes has been shown to be an important environmental axis. Freshwater snails are key players in freshwater ecosystems, but there are no comprehensive studies of their distributions across the entire freshwater habitat gradient. Here we test the hypothesis that snail species in the family Physidae are distributed in a non‐random manner across the habitat gradient. We sampled the snails, their predators and the abiotic environment of 61 ponds and lakes, spanning a wide range in depth and hydroperiod. 2. Temporary habitats had the lowest biomass of predators. Shallow permanent ponds had the highest biomass of invertebrate predators but an intermediate fish biomass. Deep ponds and lakes had the highest fish biomass and intermediate invertebrate biomass. Five species of physids occurred in the regional species pool and 60 of the 61 ponds and lakes surveyed contained physid snails. Each pond and lake contained an average of just 1.2 physid species, illustrating limited membership in local communities and substantial among‐site heterogeneity in species composition. 3. Physids showed strong sorting along the habitat gradient, with Physa vernalis found in the shortest hydroperiod ponds and Aplexa elongata, P. gyrina, P. acuta and P. ancillaria found in habitats of successively greater permanence. When organised into a site‐by‐species incidence matrix with sites ordered according to their hydroperiods, we found the pattern of incidence to be highly coherent, showing that much of the heterogeneity in species composition from one pond to another is explained by hydroperiod. We also found that the number of species replacements along this gradient was higher than random, showing that replacement is more important than nesting in describing species composition in ponds of different hydroperiod. 4. Discriminant analysis showed that pond depth, invertebrate biomass and fish biomass were the best predictors of species composition. Analysis of these niche dimensions showed that P. vernalis and A. elongata were most successful in shallow, temporary ponds with few predators. P. gyrina and P. acuta were typically found in ponds of intermediate depth and high predator abundance. P. ancillaria was found in the deepest lakes, which had abundant fish predators but few invertebrate predators. Of the five species considered, P. ancillaria, P. vernalis and A. elongata were relatively specialised with regard to key habitat characteristics, P. gyrina was moderately generalised and P. acuta was remarkably generalised, since it alone occurred across the entire freshwater habitat gradient. The exceptional habitat breadth of P. acuta stands in contrast to distributional studies of other freshwater taxa and deserves further attention.     

Succession of Chironomus Meigen Species (Diptera,Chironomidae) in Newly Filled Ponds

The colonization by Chironomus spp. of two ponds filled after a dry period was investigated. Field data were collected by means of quantitative benthic samples and emergence traps. C. melanescens. C. annularius, C. riparius, C. piger, C. luridus, C. obtusidens, C. plumosus, C. dorsalis and Camptochironomus tentans were determined cytotaxonomically in ponds investigated. C. melanescens and C. annularius appear to be the most characteristic species colonizing in high numbers in newly filled ponds. Larvae of C. annularius grew more slowly in ponds compared with the former one which resulted in a characteristic succession of both larval types. Most species mentioned disappeared completely from the ponds investigated after the metamorphosis of a single cohort. They were replaced by C. plumosus which was often attended by C. annularius in smaller ponds.     

Plant community patterns in Moroccan temporary ponds along latitudinal and anthropogenic disturbance gradients

Background: Temporary ponds, an abundant habitat in the Maghreb region and notably in Morocco, have a high conservation value. However, they are mainly known from the north of the country.

Aims: The aim of this work was to characterise the vegetation of Moroccan temporary ponds along a combined gradient of latitude and anthropogenic pressure.

Methods: Eighty-five ponds distributed along a north–south gradient of 750 km were sampled. For each pond, all vegetation was surveyed (flooded and dry parts) and the local abiotic characteristics were measured during two successive hydrological cycles. The prevailing anthropogenic pressures were also identified and were attributed an impact score.

Results: Eighty-one characteristic pond species (including 17 rare species) were recorded, with several new distribution data in the southern part of the latitudinal gradient. Plant communities were related to climatic and anthropogenic factors, but mostly to local factors, such as maximum water depth and soil pH. The northern ponds (wettest macroclimate) were rich in characteristic species and rare species, while the southern (driest macroclimate) ponds were more species poor.

Conclusions: In addition to the direct impact of increasing human activity, a further reduction of the floristic richness of temporary ponds is expected due to climatic changes. This is particularly the case for characteristic species which have a high conservation value.     

Plant communities as a tool in temporary ponds conservation in SW Portugal

Temporary ponds are seasonal wetlands annually subjected to extreme and unstable ecological conditions, neither truly aquatic nor truly terrestrial. This habitat and its flora have been poorly studied and documented because of the ephemeral character of the flora, the changeable annual weather that has a great effect on the small, herbaceous taxa and the declining abundance of temporary ponds. The objectives of this study are: (a) to define plant community diversity in terms of floristic composition of ephemeral wetlands in SW Portugal, (b) to identify temporary pond types according to their vegetation composition and (c) to identify those ponds that configure the European community priority habitat (3170* – Mediterranean temporary ponds). Vegetation sampling was conducted in 29 ponds, identifying 168 species grouped among 15 plant communities. Soil texture, pH, organic C and N content were measured, but only N and percent of clay appear to be related with the distribution of each community type. The results showed that ephemeral wetlands could be classified into four type: vernal pools, marshlands, deep ponds and disturbed wetlands. Vernal pools correspond to the Mediterranean temporary ponds (3170*), protected as priority habitat under the EU Habitats Directive. Submersed Isoetes species (Isoetes setaceum and Isoetes velatum) represents, together with Eryngium corniculatum, the indicator species for vernal pools. We identify also indicator plant communities of this priority habitat, namely I. setaceum and E. corniculatum–Baldellia ranunculoides plant communities. In this region, the conservation of temporary ponds has so far been compatible with traditional agricultural activities, but today these ponds are endangered by the intensification of agriculture and the loss of traditional land use practices and by the development of tourism. Guest editors: B. Oertli, R. Cereghino, A. Hull & R. Miracle Pond Conservation: From Science to Practice. 3rd Conference of the European Pond Conservation Network, Valencia, Spain, 14–16 May 2008     

Environmental Predictors of Rotifer Community Structure in Two Types of Small Water Bodies

The species diversity and distribution of rotifers between different habitats (elodeids, helophytes and open water) of 34 field and 31 forest ponds, differing in regard to origin, size, depth, macrophyte cover, overshading and the presence of fish were examined (N = 381). 197 taxa were found in both types of ponds with 32 species being rare, endangered or new to Polish fauna. The species composition and Shannon‐Wiener index distribution reflected heterogeinity of the habitats, while rotifer mean densities revealed a reverse pattern in both types of water bodies. The great variability of limnological features contributed to a lack of significant differences in rotifer abundance between both types of water bodies. Although some rotifers preferred one specific type of water body (forest vs. field), the type of habitat was a much stronger predictor of their distribution, which reflects a necessity to examine ponds in relation to their microhabitats created by various macrophytes. Rotifers revealed a strict division into two groups – of pelagic origin (e.g., Polyarthra vulgaris), which were attributed to the open water and helophytes, and of littoral origin (e.g., Lepadella patella), which were associated with elodeids, biomass of a plant habitat and a lack of fish. The selective choice of the most complex habitat (elodeids) by only littoral species suggests the weak impact of fish in the studied ponds and the most advantageous conditions for littoral rotifers among such a habitat. The first group comprised species characteristic of field ponds, while the second was characteristic of forest ponds. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Habitat structure determines spider diversity in highland ponds

Wetlands (e.g. ponds, meadows) can be found in many landscapes, playing an important role in maintaining regional biodiversity and supporting heterogeneous communities. Spiders are diversified predators that are highly influenced by changes in plant community structure, heterogeneous habitats sustain high spider diversity and abundance. We investigated the characteristics of spider biodiversity in ponds with different habitat structures, by examining patterns across habitats of ponds with different vegetation levels. Sampling took place in four occasions over a year. We compared spider abundance, species richness and composition among ponds including distinct vegetation variables, related to life form, type of leaves, coverage and height. Overall 1174 individuals (194 adults) of 11 families and 37 morphospecies were sampled. We found mostly expected differences in the manner that communities were structured between different habitats. Thus, higher variability of abundance was explained for higher habitat structure of ponds. We also found differences in species composition between ponds with low emergent vegetation and higher habitat structures. Additionaly, spiders were consistently structured more by turnover than nestedness components, with a greater beta diversity of web-builders. Our results suggest varying levels of habitat structures and species substitution shape pond spider communities, depending on habitat heterogeneity and spider guild. Those findings demonstrate the clear role of spatial habitat structure, with more spider species preferring to build webs or actively hunt at vegetated environments on ponds.     

The influence of white seabream (Diplodus sargus) production on macrobenthic colonization patterns

The present work evaluates the influence of fish production on macrobenthic colonization over large areas (approximately 700 m²), where the colonizing populations are not nearby the disturbed area. Sampling was undertaken within newly created aquaculture earthen ponds under two contrasting conditions: white seabream (Diplodus sargus) production and no production (control). Macrobenthic and geochemical samples were collected 7, 23, 54, 93 and 180 days after filling the earthen ponds with seawater pumped from a water reservoir for the first time. The water reservoir was also sampled, and is used as a reference for the colonizing populations. Macrobenthic colonization rate in the ponds was low, probably due to the isolation of the disturbed habitat, to the large size of the defaunated area, and possibly to geochemical constraints. Initial colonization was by insect larvae (mainly chironomids), the bivalves Cerastoderma spp., the polychaetes Pseudopolydora paucibranchiata and Hydrodoides elegans, and nemerteneans. The number of species was similar in control and production ponds, even though under production higher total abundance values were observed. Although well represented in the water reservoir, the amphipod Microdeutopus gryllotalpa was only observed within the new ponds after 6 months. Preliminary results suggest that macrobenthic colonization patterns were influenced by fish production, as assemblages were significantly different among ponds. Higher food availability due to fish production may explain the results obtained, but ecological reasons, such as predation, may also contribute for shaping the macrobenthic communities.     

Emergence of Chironomidae from Findley Lake and two ponds in the Cascade Mountains,U.S.A.

From Findley Lake and two ponds in the Cascade Mountains (U.S.A.) Chironomidae started to emerge as soon as the ice thawed in 1972 and 1973. The 1051 Chironomidae that emerged per m² from Findley Lake included 307 individuals ofTanytarsus and 358 ofProcladius. Tanytarsus outnumberedChironomus at all depths from 0 to 19.3 m. The 1506 Chironomidae that emerged per m² from the 4.5 m deep pond included 997 individuals ofTanytarsus. The 1490 Chironomidae that emerged per m² from the 2 m deep pond included 1363 Tanytarsus. The emerging biomass was 216 and 186 mg dry weight per m² in Findley Lake and the 4.5 m deep pond, respectively, and only 78 mg in the 2 m deep pond. Most species had their maximum emergence where there was organic detritus from the surrounding forest.Orthocladius emerged from sand bottom at 2.7 to 5.2 m depth.Stictochironomus emerged from mud and sand at 8.4 m depth.Chironomus emerged from soft mud at 15 to 27.5 m depth.     

Current status of macroinvertebrate methods used for assessing the quality of European marine waters: implementing the Water Framework Directive

Ephemeral ponds are doubly insular habitats in that they are discrete in time as well as in space. Predicting species richness based on pond size has been attempted using measures of both spatial extent and habitat duration, but habitat qualities alone only drive community composition under the species-sorting metacommunity paradigm. We tested the hypothesis that community composition in temporary ponds is driven by species sorting due to pond duration. In order to eliminate bias due to under-sampling, we sampled 34 pools distributed among 3 complexes in every ponding event over a period of six years, and identified every individual for the microcrustacean taxa. Our data were consistent with most of the predictions of the species-sorting hypothesis. There was a clear pattern of difference between ponds in species richness as well as higher species richness in years with higher rainfall. The set of crustacean species that we found in the pools was highly significantly nested across the region, but not necessarily within localized groups of ponds (complexes). We also found differences in community composition among complexes. Pond depth was the best predictor of species richness when data were summarized over the whole study, but in one year with unusually high rainfall, pond area and hydroperiod were significant but depth was not. We did find some species in all ponds. It is likely that given their short development time, ponds do not differ in habitat quality for these few species. These results taken together emphasize the variability inherent in ephemeral pond ecology, with detectable differences in crustacean communities and the factors influencing them between years as well as between ponds, and at scales of meters as well as kilometers. Although our data provide further evidence that species sorting on pond permanence is an important factor structuring temporary pond crustacean communities, our assumption that dispersal is not limiting still needs to be tested.

Some noteworthy Desmids from Shimoga district,Karnataka State (India)

Freshwater algal collections in ponds and lakes of Shimoga district of Karnataka State (India) during 1977–1978 contained 9 Desmid taxa with interesting variations. Two new taxa belonging to Staurastrum Meyen ex Ralfs are described.     

Assembly of zooplankton communities in newly created ponds

1. The creation or severe disturbance of habitat patches is generally followed by a phase of community (re)assembly. After such an event, the trajectory of community assembly in habitat patches may be highly variable because of stochasticity during the dispersal and colonization process. Conversely, assembly patterns may also be deterministic if communities are shaped by prevalent environmental conditions in the habitat patches (species sorting), or by systematic differences in the dispersal capacities of species. 2. In this study, we investigated the pattern of community assembly of zooplankton species in 25 newly created ponds at 13 different sites in Flanders (Belgium). Over a period of three consecutive years, we assessed at what rate and with what frequency species of the regional species pool colonized the newly created ponds. We also studied the development of community structure over time and tested whether the dynamics were consistent across different ponds at the different locations. In addition, we characterized the dynamics of metacommunity features, such as alpha, beta and gamma diversity in clusters of ponds. 3. Even within the first year after their creation, the new ponds were rapidly colonized by a small subset of species from the regional species pool (Daphnia obtusa, Chydorus sphaericus and Simocephalus vetulus). These species dominated the cladoceran assemblages during the subsequent years. Other species in the regional species pools were only sporadically able to colonize ponds. 4. During the entire study period, we observed no significant shifts in species lists or in the occurrences of species among years. The low incidence of the majority of species may be the result of dispersal limitation or the failure of immigrants to establish due to priority effects exerted by the first colonizers. There was, nevertheless, a consistent change in the relative abundance of species, which was most probably mediated by differences in the hatching time among species influencing species composition in the first year. 5. In contrast to expectations, we observed no increase in average alpha diversity (local species richness) and gamma diversity (total richness of entire pond clusters) during the course of the study period. Beta diversity was relatively low from the beginning and remained constant throughout the study period. These deterministic patterns can mainly be attributed to the dominance of the three first colonizing species and the low success rate of other species in colonizing the ponds.     

Local and landscape effects on temporary pond zooplankton egg banks: conservation implications

Understanding landscape correlates of local habitat integrity and community structure and the identification of spatial scales at which these associations operate are relevant for management and conservation of unique but globally threatened temporary ponds. We use a multivariate variance decomposition approach to determine taxon-specific associations of zooplankton communities banked in dry pond soils (rotifers, cladocerans, copepods) with local habitat features and landscape characteristics across four spatial scales (100 buffer strip, 1, 5, and 10 km scales). Results show similar degrees of correlation between rotifer and cladoceran communities with local habitat conditions (chiefly water quality). This is interpreted according to life-history traits of component species of wetland propagule banks. Associations with landscape features varied between communities with rotifers correlating with landscape structural features only at the buffer scale while cladocerans showed no significant correlations with landscape characteristics across all scales. Copepods were neither significantly associated with local nor landscape characteristics. The results of this study contrast strikingly with our previous population-based study, where populations of Triops cancriformis and Branchinecta orientales were significantly correlated with landuse features at the broadest scale. The combined results suggest that a three-way management scheme could be useful for conservation of zooplankton resting egg banks in this remnant wetland complex. These schemes could focus on the restoration of wetland water quality, the establishment of vegetated buffer strips around the ponds to counteract degradation resulting from runoff, and reforestation and/or the creation of hedgerows in agricultural catchments to avoid impacts resulting from broad-scale diffuse pollution fluxes. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Effects of forest canopy on habitat selection in treefrogs and aquatic insects: implications for communities and metacommunities

The specific dispersal/colonization strategies used by species to locate and colonize habitat patches can strongly influence both community and metacommunity structure. Habitat selection theory predicts nonrandom dispersal to and colonization of habitat patches based on their quality. We tested whether habitat selection was capable of generating patterns of diversity and abundance across a transition of canopy coverage (open and closed canopy) and nutrient addition by investigating oviposition site choice in two treefrog species (Hyla) and an aquatic beetle (Tropisternus lateralis), and the colonization dynamics of a diverse assemblage of aquatic insects (primarily beetles). Canopy cover produced dramatic patterns of presence/absence, abundance, and species richness, as open canopy ponds received 99.5% of propagules and 94.6% of adult insect colonists. Nutrient addition affected only Tropisternus oviposition, as females oviposited more egg cases at higher nutrient levels, but only in open canopy ponds. The behavioral partitioning of aquatic landscapes into suitable and unsuitable habitats via habitat selection behavior fundamentally alters how communities within larger ecological landscapes (metacommunities) are linked by dispersal and colonization.     

Relationship between freshwater gastropods and plant communities reflecting various trophic levels

Plant communities were examined in ponds in Brittany (north-west France) and then classified into six types reflecting different trophic levels: oligotrophic, oligodystrophic, mesotrophic, meso-dystrophic, meso-eutrophic an eutrophic. In 45 of these ponds, aquatic snails were sampled in order to determine the relationship between the gastropod species richness and the water trophic levels as indicated by plant community types. The second aim of this study was to determine whether some gastropod species were characteristic of a particular trophic level. The number of plant communities in the ponds was also taken into consideration.A trophic gradient was found along the F1 axis on the principal plane of the correspondence analyses. The species richnesses low or zero and especially the lymneid, Lymnaea glabra were close to the oligo-dystrophic and oligotrophic communities. In contrast, the highest numbers of snail species (5 and above) were found in the most eutrophic ponds where Hippeutis complanatus, Planorbis planorbis, Lymnaea stagnalis and Planorbarius corneus were particularly common. The latter species inhabited the ponds including on average the greatest number of macrophyte communities but no significant differences were found between snail species. The ponds which contained the greatest numbers of plant communities included the richest gastropod communities (7 and more) but also the poorest ones (0 or 1 species). Relationships between freshwater snails, macrophytes and trophic levels are discussed.Laboratoire de Zoologie et d'Ecophysiologie     

Life syndrome of the bryophyte communities as an adaptative pattern in the Mediterranean temporary ponds of Italy

An ecological and biological investigation on the bryophyte communities of the Mediterranean temporary ponds was carried out in Italy. Here, the occurrence of a rich set of liverworts is very significant, as several species of Riccia characterize the communities from a physiognomical, ecological and syntaxonomical point of view. The moss component is represented only by acrocarpous mosses, e.g. Archidium alternifolium and Pleuridium acuminatum which play an important phytosociological role. In this study, the bryophyte communities are used to identify a pattern, corresponding to a “functional type” which reflects the correlated response of the bryophyte communities toward the prevalent ecological parameters of the habitat. The individuated functional type assembles life strategy, life form, lifespan, spore size, dispersal strategy, reproduction effort, independently from the taxonomical relationship of the species characterizing the communities. It represents an adaptative pattern of coevolved characters, adopted by the bryophyte communities for the habitat establishment and re-establishment following the seasonal water fluctuations typical of the investigated habitat.     

Climate‐associated tundra thaw pond formation and range expansion of boreal zooplankton predators

Most of the freshwater component of the Earth's surface is composed of shallow tundra ponds. These high latitude ecosystems have been exposed to a variety of abiotic disturbances associated with recent environmental change. However, the biological significance of these changes remains poorly understood. Here, we characterize the abiotic disturbance to the shallow tundra ponds of northwest Alaska. We used historical aerial imagery to determine that up to 53% of the sampled ponds have formed during the recent warmer decades (since the 1970s). We discovered that two top predator species (phantom midges of the genus Chaoborus) of the freshwater zooplankton have recently undergone range expansion, forming widespread (a scale of hundreds of km) stable tundra populations. We assessed the population persistence of these boreal predators by longitudinal sampling over 14 yr. Recent thaw ponds had significantly dissimilar zooplankton communities to communities of ponds that formed before 1950. Both predator and herbivore species differed by age of pond. Younger pond ages and warmer surface temperatures were the significant predictors of the presence of temperate Chaoborus americanus in tundra ponds. Ponds containing tundra populations of C. americanus and C. cf. flavicans were associated with recent formation (83–90%). Recent ponds in river valleys appeared more important than recent ponds near roads as colonization corridors for C. americanus. Only 24% of the tundra keystone predator, Heterocope septentrionalis, populations were from recent ponds. Our results suggest that climate‐associated disturbance can lead to a widespread stable range expansion of boreal species despite the propinquity of older ponds with top‐down control exerted by an endemic keystone predator.     

The influence of flatworm predation on zooplankton inhabiting small ponds

Experiments were performed in 1977 to determine which large zooplankton in a series of high altitude ponds can be consumed by the predatory flatworm Mesostoma ehrenbergii. This predator consumes Daphnia at a high rate and the fairy shrimp Branchinecta at a low rate, but does not consume Diaptomus. Experiments were performed in 1978 and 1979 to determined the rate of predation on Daphnia in 30 liter tubs and to determine if predation rate is correlated with surface to volume ratio of experimental containers. There is a clear correlation between surface to volume ratio and predation rate. Determinations of Mesostoma and Daphnia densities were made in a series of eight high altitude ponds, and pond surface to volume ratios were determined. Examination of these parameters lends credence to the argument that Mesostoma predation affects Daphnia dynamics in some circumstances. The results suggest that benthic invertebrate predators may affect zooplankton dynamics, especially in shallow ponds.     

Freshwater diatom and macroinvertebrate diversity of coastal permanent ponds along a gradient of human impact in a Mediterranean eco-region

Mediterranean coastal areas are characterised by heavily transformed landscapes and an ever-increasing number of ponds are subjected to strong alterations. Although benthic diatoms and macroinvertebrates are widely used as indicators in freshwater ecosystems, little is still known about the diatom communities of lowland freshwater ponds in the Mediterranean region, and, furthermore, there are few macroinvertebrate-based methods to assess their ecological quality, especially in Italy. This article undertakes an analysis of benthic diatom and macroinvertebrate communities of permanent freshwater ponds, selected along a gradient of anthropogenic pressures, to identify community indicators (taxa and/or metrics) useful to evaluate the effect of human impacts. A series of 21 ponds were sampled along Tyrrhenian coast in central Italy. Five of these ponds, in a good conservations status and surrounded by woodland were selected as ‘reference sites’ for macroinvertebrates and epipelic diatoms. The remaining sixteen ponds were located in an agricultural landscape subject to different levels of human impact. The total number of macroinvertebrate taxa found in each pond was significantly higher in reference sites than in both the intermediate and heavily degraded ones, whereas the diatom species richness did not result in a good community variable to evaluate the pond ecological quality. The analysis revealed a substantial difference among the compositions of diatom communities between reference ponds and degraded ponds. The former were characterised by the presence of several species belonging to genera, such as Pinnularia sp., Eunotia sp., Stauroneis sp., Neidium sp., all of which were mostly absent from degraded ponds. Furthermore, the taxonomic richnesses of some macroinvetebrate groups (Odonata, Ephemeroptera, Trichoptera, Coleoptera), and taxa composition attributes of macroinvertebrate communities (total abundance, percentages of top three dominant taxa, percentages of Pleidae, Ancylidae, Hirudinea, Hydracarina) significantly correlated with variables linked with anthropogenic pressures. The results of the investigation suggested that diatoms tended more to reflect water chemistry through changes in community structure, whereas invertebrates responded to physical habitat changes primarily through changes in taxonomic richness. The methodologies developed for the analysis of freshwater benthic diatom and macroinvertebrate communities may have a considerable potential as a tool for assessing the ecological status of this type of water body, complying with the European Union Water Framework Directive 2000/60/EC. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Guest editors: B. Oertli, R. Cereghino, A. Hull & R. Miracle Pond Conservation: From Science to Practice. 3rd Conference of the European Pond Conservation Network, Valencia, Spain, 14–16 May 2008