scispace - formally typeset
Search or ask a question
Author

Michel Coste

Bio: Michel Coste is an academic researcher. The author has contributed to research in topics: Diatom & Water Framework Directive. The author has an hindex of 34, co-authored 77 publications receiving 3643 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, the seasonal succession of diatoms and chlorophyceae was analyzed in the Seine River system (France), which is characterized by a temperate oceanic hydrological regime and high nutrient enrichment.
Abstract: Seasonal succession of diatoms and Chlorophyceae have been analyzed in the Seine River system (France), which is characterized by a temperate oceanic hydrological regime and high nutrient enrichment. Phytoplankton development is invariably initiated by the decrease of discharge in spring. When this occurs in early spring, the bloom is dominated by diatoms that severely deplete silica, and a regular increase of their biomass is observed along the river continuum from headwaters to the estuary. The bloom occurs earlier downstream than upstream. Chlorophyceae succeed the diatoms by the end of May and represent a significant component of the summer phytoplankton population. Fluctuations of the phytoplankton biomass are observed within the continuum in summer, with high biomass in 6th-order rivers, low biomass in 7th-order rivers, and again high biomass in h the model calculates the development of diatoms and Chlorophyceae within the whole drainage network which is represented as a regular pattern of confluences of tributaries with increasing stream order. The model, taking into account both bottom-up and top-down regulating factors of phytoplankton, has proved to be a powerful tool in understanding the dynamics of a large drainage network.

319 citations

Journal ArticleDOI
TL;DR: In a metal-polluted stream in the Riou Mort watershed in SW France, periphytic diatom communities were affected by the metal but displayed induced tolerance, seen through structural impact (dominance of small, adnate species) as well as morphological abnormalities particularly in the genera Ulnaria and Fragilaria.

208 citations

Journal ArticleDOI
01 Sep 1991
TL;DR: A test of methods for assessing water quality based on diatoms is presented in this article, where the authors use a set of diatom-based methods to assess water quality.
Abstract: (1991). A test of methods for assessing water quality based on diatoms. SIL Proceedings, 1922-2010: Vol. 24, No. 4, pp. 2112-2116.

183 citations

Journal ArticleDOI
TL;DR: The new version of the BDI, called BDI-2006, was adopted by the French standardisation authority (AFNOR) in October 2007, and 2802 samples were used to create this new index, where 1063 diatom species were identified.

179 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe an intercalibration exercise, performed by the countries in the Central/Baltic Geographical Intercalibrration Group stretching from Ireland in the west to Estonia in the east and from the southern parts of Scandinavia to the northern regions of Spain and Italy (but excluding alpine regions, which were intercalibrated separately) in order to ensure that ecological status concepts and assessment levels are consistent across the EU.
Abstract: The European Union (EU)’s Water Framework Directive (WFD) requires that all Member States participate in intercalibration exercises in order to ensure that ecological status concepts and assessment levels are consistent across the EU. This paper describes one such exercise, performed by the countries in the Central/Baltic Geographical Intercalibration Group stretching from Ireland in the west to Estonia in the east and from the southern parts of Scandinavia to the northern regions of Spain and Italy (but excluding alpine regions, which were intercalibrated separately). In this exercise, methods used to measure ecological status of rivers using benthic diatoms were compared. Ecological status is estimated as the ratio between the observed value of a biological element and the value expected in the absence of significant human impact. Approaches to defining the ‘reference sites’, from which these ‘expected’ values were derived, varied from country to country. Minimum criteria were established as part of the exercise but there was still considerable variation between national reference values, reflecting typological differences that could not be resolved during the exercise. A simple multimetric index was developed to compare boundary values using two widely used diatom metrics. Boundary values for high/good status and good/moderate status set by each participant were converted to their equivalent values of this intercalibration metric using linear regression. Variation of ±0.05 EQR units around the median value was considered to be acceptable and the exercise provided a means for those Member States who fell significantly above or below this line to review their approaches and, if necessary, adjust their boundaries.

125 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: It is provided strong evidence that chemicals threaten the ecological integrity and consequently the biodiversity of almost half of the water bodies on a continental scale, based on the analysis of governmental monitoring data from 4,000 European sites.
Abstract: Organic chemicals can contribute to local and regional losses of freshwater biodiversity and ecosystem services. However, their overall relevance regarding larger spatial scales remains unknown. Here, we present, to our knowledge, the first risk assessment of organic chemicals on the continental scale comprising 4,000 European monitoring sites. Organic chemicals were likely to exert acute lethal and chronic long-term effects on sensitive fish, invertebrate, or algae species in 14% and 42% of the sites, respectively. Of the 223 chemicals monitored, pesticides, tributyltin, polycyclic aromatic hydrocarbons, and brominated flame retardants were the major contributors to the chemical risk. Their presence was related to agricultural and urban areas in the upstream catchment. The risk of potential acute lethal and chronic long-term effects increased with the number of ecotoxicologically relevant chemicals analyzed at each site. As most monitoring programs considered in this study only included a subset of these chemicals, our assessment likely underestimates the actual risk. Increasing chemical risk was associated with deterioration in the quality status of fish and invertebrate communities. Our results clearly indicate that chemical pollution is a large-scale environmental problem and requires far-reaching, holistic mitigation measures to preserve and restore ecosystem health.

574 citations

Journal ArticleDOI
TL;DR: General recommendations on European bioassessment of streams were derived from the results, including those on land use changes, hydromorphological degradation on the microhabitat scale and general degradation gradients.
Abstract: Summary 1. Periphytic diatoms, macrophytes, benthic macroinvertebrates and fish were sampled with standard methods in 185 streams in nine European countries to compare their response to degradation. Streams were classified into two main stream type groups (i.e. lowland, mountain streams); in addition, the lowland streams were grouped into four more specific stream types. 2. Principal components analysis with altogether 43 environmental parameters was used to construct complex stressor gradients for physical–chemical, hydromorphological and land use data. About 30 metrics were calculated for each sample and organism group. Metric responses to different stress types were analysed by Spearman Rank Correlation. 3. All four organism groups showed significant response to eutrophication/organic pollution gradients. Generally, diatom metrics were most strongly correlated to eutrophication gradients (85% and 89% of the diatom metrics tested correlated significantly in mountain and lowland streams, respectively), followed by invertebrate metrics (91% and 59%). 4. Responses of the four organism groups to other gradients were less strong; all organism groups responded to varying degrees to land use changes, hydromorphological degradation on the microhabitat scale and general degradation gradients, while the response to hydromorphological gradients on the reach scale was mainly limited to benthic macroinvertebrates (50% and 44% of the metrics tested correlated significantly in mountain and lowland streams, respectively) and fish (29% and 47%). 5. Fish and macrophyte metrics generally showed a poor response to degradation gradients in mountain streams and a strong response in lowland streams. 6. General recommendations on European bioassessment of streams were derived from the results.

525 citations

Journal ArticleDOI
TL;DR: Patients with cadmium toxicity need gastrointestinal tract irrigation, supportive care, and chemical decontamination traditional-based chelation therapy with appropriate new chelating agents and nanoparticle-based antidotes.
Abstract: Cadmium poisoning has been reported from many parts of the world. It is one of the global health problems that affect many organs and in some cases it can cause deaths annually. Long-term exposure to cadmium through air, water, soil, and food leads to cancer and organ system toxicity such as skeletal, urinary, reproductive, cardiovascular, central and peripheral nervous, and respiratory systems. Cadmium levels can be measured in the blood, urine, hair, nail and saliva samples. Patients with cadmium toxicity need gastrointestinal tract irrigation, supportive care, and chemical decontamination traditional-based chelation therapy with appropriate new chelating agents and nanoparticle-based antidotes. Furthermore it has been likewise recommended to determine the level of food contamination and suspicious areas, consider public education and awareness programs for the exposed people to prevent cadmium poisoning.

484 citations

Book ChapterDOI
01 Jan 2010
TL;DR: This chapter reviews the many characteristics of diatom assemblages that could be used in assessments and the methods and indices of assessment and emphasizes the importance of designing environmental assessments so that many approaches are used and results are based on rigorous statistical testing of hypotheses.
Abstract: Introduction Assessments of environmental conditions in rivers and streams with diatoms have a long history, which has resulted in the development of the two basic conceptual and analytical approaches used today. First, based on the work of Kolkwitz and Marsson (1908), autecological indices were developed to infer levels of pollution based on the species composition of assemblages and the ecological preferences and tolerances of taxa (e.g., Butcher, 1947; Fjerdingstad, 1950; Zelinka & Marvan, 1961; Lowe, 1974; Lange-Bertalot, 1979). Second, Patrick's early monitoring studies (Patrick, 1949; Patrick et al ., 1954; Patrick & Strawbridge, 1963) relied primarily on diatom diversity as a general indicator of river health (i.e., ecological integrity), because species composition of assemblages varied seasonally and species richness varied less. Thus, the concepts and tools for assessing ecosystem health and diagnosing causes of impairment in aquatic habitats, particularly rivers and streams, were established and developed between 50 and 100 years ago. The many advances in the use of diatoms and other algae for monitoring stream and river quality have been reviewed by Patrick (1973) and, more recently, by Stevenson and Lowe (1986), Round (1991), Whitton et al . (1991), Coste et al . (1991), Whitton and Kelly (1995), Rosen (1995), and Lowe and Pan (1996). There are three major objectives for this chapter. First, we emphasize the importance of designing environmental assessments so that many approaches are used and results are based on rigorous statistical testing of hypotheses. Second, we review the many characteristics of diatom assemblages that could be used in assessments and the methods and indices of assessment.

434 citations

Book ChapterDOI
TL;DR: The biochemiCal processes involved in the over production of ROS as an aftermath to heavy metal exposure are summarized and the ROS scavenging process that is associated with the antioxidant defense machinery is described.
Abstract: Environmental contamination by hazardous environmental pollutants is a widespread and increasingly serious problem confronting society, scientists, and regulators worldwide (Debenest et al 2010; Hajeb et al 2011; Nanthi and Bolan 2012; Shahid et al 2013a) Among these pollutants, the heavy metals, are a loosely-defined group of elements that are similar in that they all exhibit metallic properties, and have atomic masses >20 (excluding the alkali metals) and specific gravities >5 (Rascio and Navari-Izzo 2011) This group mainly includes transition metals, some metalloids, and the lanthanides and actinides Heavy metals can be toxic to plants, animals and humans, even at very low concentrations Heavy metals are natural components of the earth’s crust and are present in different concentrations at different sites (Shahid et al 2012a)

376 citations