Cumulative Stressors Trigger Increased Vulnerability of Diatom Communities to Additional Disturbances
- 21 April 2015
- journal article
- research article
- Published by Springer Science and Business Media LLC in Microbial Ecology
- Vol. 70 (3), 585-595
- https://doi.org/10.1007/s00248-015-0602-y
Abstract
Chronic, non-lethal stressors occurring gradually (in space or time) can result in cumulative impacts that are more dramatic than higher intensities or occasional critical levels of any single one of these stressors. The negative effects of the chronic stressors trigger lasting impacts that may grow in intensity and become problematic over time and/or to higher trophic levels. In rivers, aquatic organisms experience this type of cumulative stress along the up- to downstream gradient in natural and anthropogenic contaminants generally observed in inhabited watersheds. Diatoms are a major component of the periphyton in rivers; their richness and diversity in natural communities are directly related to their varied ecological preferences and sensitivity to disturbance. In this study, we monitored from 2003 to 2008 the changes in the diversity of taxonomic and non-taxonomic features along a small river (Riou-Mort, South West France), at three sites: one site upstream considered as a reference for this watershed, one intermediate site with high nutrient load, and one downstream site exposed to both nutrient and metal pollution. The cumulative impacts of nutrients plus metals led to a gradual decrease in species richness and diversity, and in a potential capacity to cope with additional stresses, e.g., climate change-related ones. This is reflected by a decrease in species richness downstream, more dramatic in the hot summer of 2003 than in cooler summers. With the increasingly protective environmental regulations (e.g., Water Framework Directive in Europe), accumulation of stresses on aquatic resources are recommended to receive increasing attention, in particular considering the expected changes in climate.Keywords
This publication has 42 references indexed in Scilit:
- Enhanced co-tolerance and co-sensitivity from long-term metal exposures of heterotrophic and autotrophic components of fluvial biofilmsScience of The Total Environment, 2011
- Tolerance to ContaminantsPublished by Taylor & Francis Ltd ,2011
- Functional diversity is positively associated with biomass for lake diatomsFreshwater Biology, 2010
- Light modulated toxicity of isoproturon toward natural stream periphyton photosynthesis: A comparison between constant and dynamic light conditionsAquatic Toxicology, 2010
- Recovery potential of periphytic communities in a river impacted by a vineyard watershedEcological Indicators, 2010
- Influence of phosphorus on copper sensitivity of fluvial periphyton: the role of chemical, physiological and community-related factorsEcotoxicology, 2009
- Groundwater contributions to metal transport in a small river affected by mining and smelting wasteWater Research, 2007
- Typology of diatom communities and the influence of hydro-ecoregions: A study on the French hydrosystem scaleWater Research, 2005
- EFFECTS OF BIODIVERSITY ON ECOSYSTEM FUNCTIONING: A CONSENSUS OF CURRENT KNOWLEDGEEcological Monographs, 2005
- Abundance and Vertical Distribution of the Phytobenthic Community within a Pool and Riffle Sequence of an Alpine Gravel StreamInternational Review of Hydrobiology, 2003