Variations of periphytic diatom sensitivity to the herbicide diuron and relation to species distribution in a contamination gradient: implications for biomonitoring

Roubeix, Vincent; Mazzella, Nicolás; Schouler, Laurie; Fauvelle, Vincent; Morin, Soizic; Coste, Michel; Delmas, FranÃ§ois; Margoum, C.

doi:10.1039/c0em00783h

Cited by 40 publications

(32 citation statements)

References 27 publications

(55 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Species not fixed have the ability to move within the biofilm matrix. According to Roubeix et al (2011b) or Paule et al (2013), the abundance of potentially motile taxa is expected to increase with toxic contamination. Indeed, the motile species are assumed to be able to control their refuge within the biofilm (Larras et al, 2012), or regulate the balance between access to environmental resources (light, nutrients) and exposure stress (Fore and Grafe, 2002;Laviale et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Use of diatom motility features as endpoints of metolachlor toxicity

et al. 2015

Self Cite

View full text Add to dashboard Cite

Many recent ecotoxicological studies suggest a relationship between freshwater contamination and increasing abundances of motile diatoms (potentially able to move). The capacity to escape would present advantages to species in polluted environments. However, actual motility as a response to toxicants had not been described and required experimental validation. We designed a specific experiment to assess how a field-isolated diatom (Gomphonema gracile) distributes energy to in situ resistance (increased population growth or photosynthesis) and escape (behavioral changes), when exposed to increasing concentrations of the herbicide metolachlor. We report here the dose-time dependent responses of G. gracile populations. They coped with low contamination by resisting in situ, with early hormetic responses highlighted by stimulation of chlorophyll-a fluorescence. At a higher dose, harmful impacts were observed on growth after a few days, but an earlier behavioral response suggested that higher motility (percentage of motile individuals and mean distance crossed) could be involved in escape. Our findings bring new arguments to support the implementation of real measurements instead of motility traits in toxicity assessment. Specifically, motion descriptors have been used as early-warning indicators of contamination in our study. Further works should address the reliability of these endpoints in more complex conditions (interspecific variability, behavior in the field).

show abstract

Section: Introductionmentioning

confidence: 99%

Use of diatom motility features as endpoints of metolachlor toxicity

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…In lotic ecosystems, benthic microbial assemblages are now considered as useful potential indicators of ecological status because they integrate the effects of multiple anthropogenic disturbances and have strong capacities to adapt to novel environmental conditions (Burns andRyder, 2001 andSabater et al, 2007). Field studies have thus revealed that in situ diuron exposure can induce microbial adaptation leading to an increase in diuron tolerance in phototrophic biofilm communities (Dorigo et al, 2007, Pesce et al, 2010aand Roubeix et al, 2011 and an increase in diuron biodegradation potential of heterotrophic biofilm and sediment communities (Pesce et al, 2009). These studies clearly provide evidence that adaptation to biodegradation is strongly driven by exposure of microbial communities to diuron.…”

Section: Introductionmentioning

confidence: 99%

Freshwater sediment pesticide biodegradation potential as an ecological indicator of microbial recovery following a decrease in chronic pesticide exposure: A case study with the herbicide diuron

Pesce¹,

Margoum²,

Rouard³

et al. 2013

Ecological Indicators

Self Cite

View full text Add to dashboard Cite

The aim of this study was to evaluate the use of freshwater sediment biodegradation potential as an ecological indicator for monitoring microbial recovery following a decrease in chronic pesticide exposure. For this purpose, a four-year case study (2008)(2009)(2010)(2011) was conducted in a small stream (Morcille river) long exposed to high diuron concentrations, increasing from upstream to downstream. Our results show that the ban on diuron in December 2008 resulted in a progressive decrease in its concentrations in the Morcille river over the survey period. However, diuron remained present in the water three years after the ban. The spatio-temporal variations in the sediment biodegradation potential were assessed by radiorespirometry using [ring-U-14C] diuron to estimate diuron mineralization potentials. Between autumn 2008 and autumn 2011, mean diuron mineralization percentage after 15 weeks of incubation decreased by 65% downstream and by 82% in the intermediate sector, and mean 10% diuron dissipation time values increased between 143% (downstream) and 210% (intermediate). Thus the decrease in the level of chronic diuron exposure in the river also caused a fall in sediment diuron-mineralizing capacities, revealing a corresponding recovery of microbial communities. Our results show that the use of freshwater sediment biodegradation potential may be useful for assessing microbial recovery after a decrease in chronic exposure to pollutants, opening prospects for developing a new class of ecological indicator to monitor the recovery of biological quality of water resources. In this way, the use of molecular approaches based on direct extraction of nucleic acids from environmental matrices and their subsequent analysis by PCR-based approaches to quantify the abundance of pesticide-degrading communities could represent a promising alternative. Highlights► We performed a 4-year survey in a river long exposed to diuron. ► The ban on diuron resulted in a gradual fall in its concentrations in the river. ► Sediment diuron biodegradation potential decreased throughout the survey. ► Degradation capacities can be an ecological indicator to gauge microbial recovery.

show abstract

“…These herbicides are regularly found in the middle of Lake Geneva (Ortelli et al 2013) as well as at the littoral zone (diuron, 0.004-0.0257 nM; isoproturon, 0.009 nM; atrazine, 0.005-0.0278 nM; terbutryn, 0.004-0.008 nM) (INRA, unpublished data). Photosystem II (PSII) inhibitors are phytotoxic, and their environmental residues have a deleterious effect on diatoms, even at low concentrations (Tang et al 1997;Lockert et al 2006;Roubeix et al 2011;Larras et al 2012). In shallow water zones, benthic diatoms are crucial primary producers which account for a considerable proportion of the fixed biomass and carry out some of the main biochemical processes.…”

Section: Introductionmentioning

confidence: 99%

Comparison of specific versus literature species sensitivity distributions for herbicides risk assessment

Larras

Gregorio

Bouchez

et al. 2015

Environ Sci Pollut Res

View full text Add to dashboard Cite

Species sensitivity distributions (SSDs) are an important predictive tool in risk assessment. Usually, literature data are used to build SSDs that are mostly based on planktonic species. But, to get adequate protective thresholds for environmental communities, one could argue that SSD should be built on ecotoxicological data obtained from species found in the ecosystem that should be protected. This is particularly true when benthic algae are of concern. Due to the lack of literature data, building SSD on benthic microalgae is difficult. This paper aims in comparing SSDs, and thus protective thresholds (hazardous concentration that affects 5% of the species of a community, HC5), built on ecotoxicological data obtained (1) from literature and (2) with specific bioassays on benthic diatoms from a lake. Thresholds were derived for protection against four herbicides separately and for a mixture of them. Sensitivity data obtained from literature were statistically lower than the specific data for all herbicides: Species tested in the literature were usually more sensitive (mainly chlorophytes), leading to more protective lower HC5. The HC5 thresholds (literature or specific) derived for protection against the mixture were also compared to the observed sensitivity of an assemblage of benthic diatom species exposed to an increasing range of herbicide mixture concentrations. We observed that one species within the assemblage (Fragilaria rumpens) was affected at a concentration below both the literature and the specific HC5 thresholds.

show abstract

Variations of periphytic diatom sensitivity to the herbicide diuron and relation to species distribution in a contamination gradient: implications for biomonitoring

Cited by 40 publications

References 27 publications

Use of diatom motility features as endpoints of metolachlor toxicity

Use of diatom motility features as endpoints of metolachlor toxicity

Freshwater sediment pesticide biodegradation potential as an ecological indicator of microbial recovery following a decrease in chronic pesticide exposure: A case study with the herbicide diuron

Comparison of specific versus literature species sensitivity distributions for herbicides risk assessment

Contact Info

Product

Resources

About