title: A review of current knowledge on toxic benthic freshwater cyanobacteria--ecology, toxin production and risk management.
abstract: Benthic cyanobacteria are found globally in plethora of environments. Although they have received less attention than their planktonic freshwater counterparts, it is now well established that they produce toxins and reports of their involvement in animal poisonings have increased markedly during the last decade. Most of the known cyanotoxins have been identified from benthic cyanobacteria including: the hepatotoxic microcystins, nodularins and cylindrospermopsins, the neurotoxic saxitoxins, anatoxin-a and homoanatoxin-a and dermatotoxins, such as lyngbyatoxin. In most countries, observations of toxic benthic cyanobacteria are fragmented, descriptive and in response to animal toxicosis events. Only a limited number of long-term studies have aimed to understand why benthic proliferations occur, and/or how toxin production is regulated. These studies have shown that benthic cyanobacterial blooms are commonly a mixture of toxic and non-toxic genotypes and that toxin concentrations can be highly variable spatially and temporally. Physiochemical parameters responsible for benthic proliferation vary among habitat type with physical disturbance (e.g., flow regimes, wave action) and nutrients commonly identified as important. As climatic conditions change and anthropogenic pressures on waterways increase, it seems likely that the prevalence of blooms of benthic cyanobacteria will increase. In this article we review current knowledge on benthic cyanobacteria: ecology, toxin-producing species, variables that regulate toxin production and bloom formation, their impact on aquatic and terrestrial organisms and current monitoring and management strategies. We suggest research needs that will assist in filling knowledge gaps and ultimately allow more robust monitoring and management protocols to be developed.
authors.affiliation: MNHN, UMR 7245, 57 rue Cuvier, CP39, 75231 Paris Cedex 05, France; Université Paris Diderot, 5 rue T. Mann, 75013 Paris, France. Electronic address: quiblier@mnhn.fr.
authors.forename: Quiblier
authors.initials: Q
authors.lastname: Catherine
authors.forename: Wood
authors.initials: W
authors.lastname: Susanna
authors.forename: Echenique-Subiabre
authors.initials: ES
authors.lastname: Isidora
authors.forename: Heath
authors.initials: H
authors.lastname: Mark
authors.forename: Villeneuve
authors.initials: V
authors.lastname: Aurélie
authors.forename: Humbert
authors.initials: H
authors.lastname: Jean-François
mesh_terms: D001427:Bacterial Toxins / Q000378:metabolism*; D000458:Cyanobacteria / Q000378:metabolism*; D004463:Ecology; D005618:Fresh Water / Q000382:microbiology*; D012308:Risk Management
chemical_list: D001427:Bacterial Toxins
keywords: Ecology; Monitoring; Risk assessment; Toxic benthic cyanobacteria; Toxin production