A comparison of bacteria and benthic invertebrates as indicators of ecological health in streams

Lear, Gavin; Boothroyd, Ian; Turner, Susan; Roberts, Kelly; Lewis, Gillian

doi:10.1111/j.1365-2427.2009.02190.x

Cited by 56 publications

(27 citation statements)

References 38 publications

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“…Site 1 is home to diverse and abundant benthic macroinvertebrates, while site 4 has a macrobenthic invertebrate fauna of very low diversity, consisting almost entirely of chironomid larvae (38). Biofilms at site 1 may therefore be subjected to very different grazing pressures than biofilms at site 4, which is likely to further affect the nutrient resources available in these streams.…”

Section: Vol 75 2009 Diversity Of Ciliates In Stream Biofilms 5267mentioning

confidence: 99%

Relative Diversity and Community Structure of Ciliates in Stream Biofilms According to Molecular and Microscopy Methods

Dopheide

Lear

Stott

et al. 2009

Appl Environ Microbiol

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Ciliates are an important component of aquatic ecosystems, acting as predators of bacteria and protozoa and providing nutrition for organisms at higher trophic levels. Understanding of the diversity and ecological role of ciliates in stream biofilms is limited, however. Ciliate diversity in biofilm samples from four streams subject to different impacts by human activity was assessed using microscopy and terminal restriction fragment length polymorphism (T-RFLP) analysis of 18S rRNA sequences. Analysis of 3 and 5 terminal fragments yielded very similar estimates of ciliate diversity. The diversity detected using microscopy was consistently lower than that suggested by T-RFLP analysis, indicating the existence of genetic diversity not apparent by morphological examination. Microscopy and T-RFLP analyses revealed similar relative trends in diversity between different streams, with the lowest level of biofilm-associated ciliate diversity found in samples from the least-impacted stream and the highest diversity in samples from moderately to highly impacted streams. Multivariate analysis provided evidence of significantly different ciliate communities in biofilm samples from different streams and seasons, particularly between a highly degraded urban stream and less impacted streams. Microscopy and T-RFLP data both suggested the existence of widely distributed, resilient biofilm-associated ciliates as well as ciliate taxa restricted to sites with particular environmental conditions, with cosmopolitan taxa being more abundant than those with restricted distributions. Differences between ciliate assemblages were associated with water quality characteristics typical of urban stream degradation and may be related to factors such as nutrient availability and macroinvertebrate communities. Microscopic and molecular techniques were considered to be useful complementary approaches for investigation of biofilm ciliate communities.Heterotrophic microeukaryotes such as ciliates are thought to be of considerable importance in aquatic ecosystems, as they are major predators of bacteria and constitute a nutritional resource for other protozoa, invertebrates, and probably fish larvae (9,22,36,52,62,63,71). In addition, protozoan bacterivory contributes to enhanced decomposition of leaf detritus-a vital nutrient resource in streams-by increasing turnover of bacterial populations through predation (57). It is not well understood, however, how ciliate diversity and community structure in streams are affected by changing environmental conditions, or how ciliate communities affect other stream biota and processes. The effects of various physical, chemical, and biological factors on freshwater protozoan communities have been considered by a number of studies, but most of these have focused upon planktonic organisms in lentic habitats (for example, see references 2, 11, and 44). However, the complex microbial communities in biofilms have been recognized as important contributors to critical ecological processes, such as auxotrophic primary ...

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Section: Vol 75 2009 Diversity Of Ciliates In Stream Biofilms 5267mentioning

confidence: 99%

Relative Diversity and Community Structure of Ciliates in Stream Biofilms According to Molecular and Microscopy Methods

Dopheide

Lear

Stott

et al. 2009

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Nevertheless, the analysis of microbial communities may provide a useful alternative measure of ecosystem health since (1) microorganisms are ubiquitous and require little sampling effort, (2) there is minimal site disturbance associated with collecting small volumes of sediment, biofilm or water for microbial community analysis, (3) the rapid life cycle of microorganisms means they may be rapid indicators of environmental change and (4) numerous methods are now available with which to characterise the genetic diversity of aquatic microbial communities using rapid community DNA fingerprinting techniques such as denaturing gradient gel electrophoresis (DGGE; Lyautey et al 2003), terminal restriction fragment length polymorphism (T-RFLP; Dopheide et al 2009) and automated ribosomal intergenic spacer analysis (ARISA; Jones et al 2007). For example, Lear et al (2009a) recently used ARISA to characterise bacterial communities within stream biofilms and identified that these communities could provide a more sensitive indicator of ecological health than macroinvertebrates within highly impacted streams. Adopting a similar approach, Stein et al (2010) analysed the fauna and bacteria within groundwater aquifers revealing that both communities responded to the environmental impacts occurring on the surface of the land.…”

Section: Introductionmentioning

confidence: 99%

A comparison of bacterial, ciliate and macroinvertebrate indicators of stream ecological health

et al. 2011

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We evaluate the reliability of communities of bacteria and ciliated protozoa as indicators of freshwater ecological health. Samples of epilithic biofilm were taken from 18 freshwater streams, impacted by varying types and degrees of catchment modification. Communities of bacteria and ciliates were characterised using DNA fingerprinting techniques (automated ribosomal intergenic spacer analysis and terminal restriction fragment length polymorphism, respectively) and macroinvertebrate data also obtained, for comparison. Similar to the macroinvertebrates, the taxa richness of ciliate communities was reduced in more developed stream catchments; significant differences in the evenness of ciliate communities were also detected. We could identify no significant relationship between the richness of bacterial taxa and the percentage catchment development. However, a significant trend was detected between bacterial community structure and the predominant catchment land use (rural vs. urban) using a Bray-Curtis measure of similarity, a relationship not detected for the ciliate and macroinvertebrate communities. These findings indicate that stream bacterial, ciliate and macroinvertebrate communities each respond differently to various catchment conditions and highlight the potential of microbial communities to provide novel, alternative indicators of stream ecosystem health.

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“…The bacterial community composition within every sample was analysed using automated ribosomal intergenic spacer analysis (or ARISA) following the method of (Lear et al, 2009) with the primers LDBact (5 0 -CCGGGTTTCCCCATTCGG-3 0 ) and SDBact (5 0 -TG CGGCTGGATCCCCTCCTTC-3 0 ) (Ranjard et al, 2001). The protocol of Ramette (2009) was used to identify 'true peaks' from ARISA electropherograms (that is, removing background noise generated during automated analysis) and bin fragments of similar size (using a selection window of 2 bp with a shift size of 0.1 bp).…”

Section: Bacterial Biogeography In Alpine Ponds G Lear Et Almentioning

confidence: 99%

Fine-scale spatial patterns in bacterial community composition and function within freshwater ponds

et al. 2014

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The extent to which non-host-associated bacterial communities exhibit small-scale biogeographic patterns in their distribution remains unclear. Our investigation of biogeography in bacterial community composition and function compared samples collected across a smaller spatial scale than most previous studies conducted in freshwater. Using a grid-based sampling design, we abstracted 100 þ samples located between 3.5 and 60 m apart within each of three alpine ponds. For every sample, variability in bacterial community composition was monitored using a DNAfingerprinting methodology (automated ribosomal intergenic spacer analysis) whereas differences in bacterial community function (that is, carbon substrate utilisation patterns) were recorded from Biolog Ecoplates. The exact spatial position and dominant physicochemical conditions (for example, pH and temperature) were simultaneously recorded for each sample location. We assessed spatial differences in bacterial community composition and function within each pond and found that, on average, community composition or function differed significantly when comparing samples located 420 m apart within any pond. Variance partitioning revealed that purely spatial variation accounted for more of the observed variability in both bacterial community composition and function (range: 24-38% and 17-39%) than the combination of purely environmental variation and spatially structured environmental variation (range: 17-32% and 15-20%). Clear spatial patterns in bacterial community composition, but not function were observed within ponds. We therefore suggest that some of the observed variation in bacterial community composition is functionally 'redundant'. We confirm that distinct bacterial communities are present across unexpectedly small spatial scales suggesting that populations separated by distances of 420 m may be dispersal limited, even within the highly continuous environment of lentic water.

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A comparison of bacteria and benthic invertebrates as indicators of ecological health in streams

Cited by 56 publications

References 38 publications

Relative Diversity and Community Structure of Ciliates in Stream Biofilms According to Molecular and Microscopy Methods

Relative Diversity and Community Structure of Ciliates in Stream Biofilms According to Molecular and Microscopy Methods

A comparison of bacterial, ciliate and macroinvertebrate indicators of stream ecological health

Fine-scale spatial patterns in bacterial community composition and function within freshwater ponds

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