title: Trait modality distribution of aquatic macrofauna communities as explained by pesticides and water chemistry.
abstract: Analyzing functional species' characteristics (species traits) that represent physiological, life history and morphological characteristics of species help understanding the impacts of various stressors on aquatic communities at field conditions. This research aimed to study the combined effects of pesticides and other environmental factors (temperature, dissolved oxygen, dissolved organic carbon, floating macrophytes cover, phosphate, nitrite, and nitrate) on the trait modality distribution of aquatic macrofauna communities. To this purpose, a field inventory was performed in a flower bulb growing area of the Netherlands with significant variation in pesticides pressures. Macrofauna community composition, water chemistry parameters and pesticide concentrations in ditches next to flower bulb fields were determined. Trait modalities of nine traits (feeding mode, respiration mode, locomotion type, resistance form, reproduction mode, life stage, voltinism, saprobity, maximum body size) likely to indicate pesticides impacts were analyzed. According to a redundancy analysis, phosphate -and not pesticides- constituted the main factor structuring the trait modality distribution of aquatic macrofauna. The functional composition could be ascribed for 2-4 % to pesticides, and for 3-11 % to phosphate. The lack of trait responses to pesticides may indicate that species may have used alternative strategies to adapt to ambient pesticides stress. Biomass of animals exhibiting trait modalities related to feeding by predation and grazing, presence of diapause form or dormancy, reproduction by free clutches and ovoviviparity, life stage of larvae and pupa, was negatively correlated to the concentration of phosphate. Hence, despite the high pesticide pollution in the area, variation in nutrient-related stressors seems to be the dominant driver of the functional composition of aquatic macrofauna assembly in agricultural ditches.
authors.affiliation: Institute of Environmental Sciences, Leiden University, P.O. Box 9518, 2300, Leiden, RA, The Netherlands. ieromina@cml.leidenuniv.nl.
authors.forename: O
authors.initials: O
authors.lastname: Ieromina
authors.affiliation: Institute of Environmental Sciences, Leiden University, P.O. Box 9518, 2300, Leiden, RA, The Netherlands.
authors.forename: C J M
authors.initials: CJ
authors.lastname: Musters
authors.affiliation: Institute of Environmental Sciences, Leiden University, P.O. Box 9518, 2300, Leiden, RA, The Netherlands.
authors.forename: P M
authors.initials: PM
authors.lastname: Bodegom
authors.affiliation: Institute of Environmental Sciences, Leiden University, P.O. Box 9518, 2300, Leiden, RA, The Netherlands.|National Institute for Public Health and Environment, P.O. Box 1, 3720, Bilthoven, BA, The Netherlands.
authors.forename: W J G M
authors.initials: WJ
authors.lastname: Peijnenburg
authors.affiliation: Institute of Environmental Sciences, Leiden University, P.O. Box 9518, 2300, Leiden, RA, The Netherlands.
authors.forename: M G
authors.initials: MG
authors.lastname: Vijver
mesh_terms: D000383:Agriculture; D000818:Animals; D059001:Aquatic Organisms / Q000187:drug effects / Q000502:physiology*; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry; D007448:Invertebrates / Q000187:drug effects / Q000502:physiology; D009426:Netherlands; D010575:Pesticides / Q000032:analysis* / Q000633:toxicity; D013045:Species Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical
keywords: Aquatic community; Environmental factors; Nutrients; Pesticides stress; Traits