title: Contaminants as habitat disturbers: PAH-driven drift by Andean paramo stream insects.
abstract: Contaminants can behave as toxicants, when toxic effects are observed in organisms, as well as habitat disturbers and fragmentors, by triggering avoidance responses and generating less- or uninhabited zones. Drift by stream insects has long been considered a mechanism to avoid contamination by moving to most favorable habitats. Given that exploration and transportation of crude oil represent a threat for surrounding ecosystems, the key goal of the present study was to assess the ability of autochthonous groups of aquatic insects from the Ecuadorian paramo streams to avoid by drift different concentrations of polycyclic aromatic hydrocarbons (PAH) contained in the soluble fraction of locally transported crude oil. In the laboratory, different groups of insects were exposed to PAH for 12h. Three different assays, which varied in taxa and origin of the organisms, concentrations of PAH (0.6-38.8µgL(-1)), and environment settings (different levels of refuge and flow) were performed. For Anomalocosmoecus palugillensis (Limnephilidae), drift was a major cause of population decline in low concentration treatments but at higher concentrations mortality dominated. PAH was highly lethal, even at lower concentrations, for Chironomidae, Grypopterygidae (Claudioperla sp.) and Hydrobiosidae (Atopsyche sp.), and, therefore, no conclusion about drift can be drawn for these insects. Contamination by PAH showed to be a threat for benthic aquatic insects from Ecuadorian paramo streams as it can cause a population decline due to avoidance by drift and mortality.
authors.affiliation: IMAR-Instituto do Mar, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal; Central Department of Research (DCI), Universidad Laica Eloy Alfaro de Manabí (ULEAM), Ciudadela Universitaria, vía San Mateo, Manta, Ecuador. Electronic address: cristiano.araujo@icman.csic.es.
authors.forename: Cristiano V M
authors.initials: CV
authors.lastname: Araújo
authors.affiliation: IMAR-Instituto do Mar, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal.
authors.forename: Matilde
authors.initials: M
authors.lastname: Moreira-Santos
authors.affiliation: IMAR-Instituto do Mar, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal.
authors.forename: José P
authors.initials: JP
authors.lastname: Sousa
authors.affiliation: Universidad San Francisco de Quito, Colegio de Ciencias Biológicas y Ambientales, Diego de Robles y Vía Interoceánica, 17-1200-841 Quito, Ecuador.
authors.forename: Valeria
authors.initials: V
authors.lastname: Ochoa-Herrera
authors.affiliation: IMAR-Instituto do Mar, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal; Universidad San Francisco de Quito, Colegio de Ciencias Biológicas y Ambientales, Diego de Robles y Vía Interoceánica, 17-1200-841 Quito, Ecuador.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Encalada
authors.affiliation: IMAR-Instituto do Mar, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Ribeiro
mesh_terms: D000818:Animals; D002683:Chironomidae / Q000187:drug effects; D017753:Ecosystem; D004784:Environmental Monitoring; D007313:Insecta / Q000187:drug effects*; D010578:Petroleum / Q000633:toxicity*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity; D045483:Rivers; D013020:South America; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical
keywords: Avoidance; Ecuadorian paramo; Oil spill; Polycyclic aromatic hydrocarbons; Stream insects