Diatom responses to zinc contamination along a Mediterranean river

Abstract

Background and aims -Diatom-based water quality management is increasing, and specific indicators are required for the assessment of priority substances such as metals. We tested a variety of features of diatom communities, in a river exhibiting a gradient of zinc contamination (the Riera d'Osor, Spain), to determine the most relevant ones. Key results -Community composition changed over time of exposure, and with the intensity of metal contamination. Species richness was significantly lower at the most contaminated sites. Species composition was more even under background and low exposure levels, but low metal inputs selected for varieties of Cocconeis placentula (var. placentula, euglypta and lineata). Small taxa (Eolimna minina, or Achnanthidium minutissimum and A. pyrenaicum) dominated in the most contaminated sites, and deformed diatom cells were found abundant. Conclusions -Although species composition clearly responded to varied levels of zinc pollution, combining cell size classes or total biovolume of the community and percentages of deformities allowed reliable assessment of the presence, and intensity, of contamination. These descriptors present the major advantage of being independent of regional taxonomic peculiarities, thus providing robust assessment irrespective of the area studied.

Morphology, typification and critical analysis of some ecologically important small naviculoid species (Bacillariophyta)

“…nonnull.) is more related to human-impacted conditions of eutrophication, pesticides, heavy metal pollution and organically polluted environments (lanGe-bertalot & boniK 1976;Weber & mcFarland 1981;dayner & johansen 1991;delGado & pardo 2014;morin et al 2014;moisset et al 2015). Indeed the population from Luxembourg illustrated here (Figs 319-349) was accompanied by species characteristic of organically polluted waters such as Navicula subminuscula manGuin, Fistulifera saprophila (lanGe-bert.…”

Potential effects of sediment contaminants on diatom assemblages in coastal lagoons of New Jersey and New York States

“…Several researchers used mesocosms and artificial streams to study freshwater diatom community composition changes in response to contaminant exposure (Pérès et al,1997;Gold et al, 2003;Kim Tiam et al, 2015). Ivorra et al (1999) and Morin et al (2014) documented the effect of zinc exposure on lotic diatom communities using in situ translocation experiments. While experimental work is indispensable for establishing causal relationships between pollutants and organisms, field surveys are important for detecting potential effects of contaminants on whole communities in situ and for observing the ecosystem-level effects.…”

Freshwater Diatoms as Indicators of Combined Long-Term Mining and Urban Stressors in Junction Creek (Ontario, Canada)

“…Diatoms have also been used to specifically reflect metal contamination, and metal-tolerant species are promising indicators of contamination (see Morin et al [15] and references therein). Moreover, deformities in diatom frustules (silica shells) are used as a biomarker in response to environmental perturbations such as contamination by metals and organic compounds (e.g., [16][17][18]). …”