Use of microbenthic algal communities in ecotoxicological tests for the assessment of water quality: the Ter river case study

Univ. de Barcelona
Journal of Applied Phycology (Impact Factor: 2.49). 01/2002; 14:41-48. DOI: 10.1023/A:1015242301451

ABSTRACT The tolerance of microbenthic algal communities to two model toxicants, atrazine and copper, was studied in the Ter river during spring and summer. Artificial substrata were colonised at 9 sites and used to perform short-term (1-4 h) toxicity tests in the laboratory and to obtain photon yield as the ecotoxicological endpoint. The tolerance was lower in spring than in summer for both toxic substances and varied according to the site studied. Copper toxicity was associated with physico-chemical conditions (total suspended solids and water pH) and, especially, with several biomass-related parameters, whereas atrazine toxicity was related to algal abundance and species composition. Temporal and spatial changes in nutrient concentration may alter the biomass and species composition of the communities and thus affect their tolerance to toxic substances. It has to be therefore considered that the environmental characteristics of the river system may determine relevant direct and indirect effects on the algal communities, then affecting their specific ecotoxicological responses. Once this is assumed, the empirical expressions obtained on calculating EC50 and EC10 can be used to predict the community-level transient effects of toxic exposures.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Water resources are directly and indirectly affected by anthropogenic activities (e.g., changes in land use) and natural factors (e.g., climate change), that is, global change. The Mediterranean basin is one of the most vulnerable regions of the world to global change, and one of the “hot spots” for forthcoming problems of water availability. The present review provides an overview about the relationship between chemical quality (especially concerning organic microcontaminants) and water scarcity, particularly in the Mediterranean area. We include an overview of environmental contaminants and analytical methodologies and consider the fate and the behavior of organic contaminants, and the effects of pollutants on ecosystems.
    TrAC Trends in Analytical Chemistry 09/2011; 30(8):1269-1278. DOI:10.1016/j.trac.2011.04.012 · 6.61 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A small hydrological basin (Lerma, NE Spain), transformed from its natural state (steppe) to rain-fed agriculture and recently to irrigation agriculture, has been monitored across four seasons of an agricultural year. The goal of this study was to assess how and whether agricultural activities impacted the nearby freshwater ecosystems via runoff. Specifically, we assessed the toxicity of three triazine herbicides, terbuthylazine, atrazine and simazine on the photosynthetic efficiency and structure of algal benthic biofilms (i.e., phototropic periphyton) in the small creek draining the basin. It was expected that the seasonal runoff of the herbicides in the creek affected the sensitivity of the periphyton in accord with the rationale of the Pollution Induced Community Tolerance (PICT): the exposure of the community to pollutants result in the replacement of sensitive species by more tolerant ones. In this way, PICT can serve to establish causal linkages between pollutants and the observed biological impacts. The periphyton presented significantly different sensitivities against terbuthylazine through the year in accord with the seasonal application of this herbicide in the crops nowadays. The sensitivity of already banned herbicides, atrazine and simazine does not display a clear seasonality. The different sensitivities to herbicides were in agreement with the expected exposures scenarios, according to the agricultural calendar, but not with the concentrations measured in water, which altogether indicates that the use of PICT approach may serve for long-term monitoring purposes. That will provide not only causal links between the occurrence of chemicals and their impacts on natural communities, but also information about the occurrence of chemicals that may escape from traditional sampling methods (water analysis). In addition, the EC50 and EC10 of periphyton for terbuthylazine or simazine are the first to be published and can be used for impact assessments.
    Science of The Total Environment 07/2014; 503. DOI:10.1016/j.scitotenv.2014.06.108 · 3.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Periphyton communities are an integral component of freshwater ecosystems and the desire to include data from toxicity testing with these organisms for ecological risk assessment is growing. This study developed sampling, storage, and exposure methods for the consistent and effective characterization of acute response and recovery of field-derived periphyton to photosystem II (PSII) inhibiting herbicides, particularly atrazine. Pulse amplitude modulated fluorometry was used to assess PSII quantum yield. For the method development phase, periphyton samples were collected from lotic and lentic systems in the Guelph, Ontario, Canada area during the summer of 2011. Following method development, native periphyton communities from three agricultural streams from the midwestern U.S. were sampled and exposed to atrazine (10-320 μg/L) and assessed for inhibition of PSII quantum yield (from 2 up to 24 h) and subsequent recovery upon cessation of exposure (up to 48 h post-exposure). Sensitivity to atrazine (EC10 and EC50 values) varied slightly (typically less than twofold difference) by site, date of sampling, and exposure interval. Only the highest initial test concentrations (160 or 320 μg/L) demonstrated greater than ~5 % inhibition at 48 h post-exposure; however all other test concentrations recovered to within 5 % of control levels, typically within 24 h. The rapid physiological recovery of periphyton communities upon atrazine removal supports the conclusion that acute exposure will not likely result in significant or sustained impacts on either structure or function of periphyton in lotic ecosystems. For ecological risk assessment, this suggests the current approach of relying on direct effects data for the most sensitive single species alone may result in overly conservative estimates of potential effects, especially for complex communities of primary producers.
    Ecotoxicology 09/2013; DOI:10.1007/s10646-013-1123-4 · 2.50 Impact Factor

Full-text (2 Sources)

Available from
May 30, 2014