Trait modality distribution of aquatic macrofauna communities as explained by pesticides and water chemistry
Ecotoxicology
Trait modality distribution of aquatic macrofauna communities as explained by pesticides and water chemistry
O. Ieromina 0 1
C. J. M. Musters 0 1
P. M. Bodegom 0 1
W. J. G. M. Peijnenburg 0 1
M. G. Vijver 0 1
0 National Institute for Public Health and Environment , P.O. Box 1, 3720 Bilthoven, BA , The Netherlands
1 & O. Ieromina
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
Aquatic community; Traits; Pesticides stress; Environmental factors; Nutrients
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Institute of Environmental Sciences, Leiden University,
P.O. Box 9518, 2300 Leiden, RA, The Netherlands
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.
Introduction
Traditionally, the responses of biotic communities to
human-induced disturbances have been evaluated based on
taxonomic approaches, e.g. by estimating the species
composition or the performance of selected indicator
species
(Mouillot et al. 2006)
. During the recent decades, the
use of traits-based approaches, i.e. characterizing
communities according to functional characteristics, has gained an
increasing interest. The reason is that functional traits were
shown to reflect the mechanisms underlying community
responses to environmental drivers
(Poff 1997; Statzner
and Beche 2010)
. Information obtained using traits-based
approaches may thus be extrapolated to a broader range of
species and geographical zones
(Baird et al. 2008; Dole´dec
et al. 2006; Charvet et al. 2000)
. These approaches have
been successfully developed for a wide array of plant
(for
instance, Engelhardt 2006; Que´tier et al. 2007; Suding
et al. 2008; Van Bodegom et al. 2014)
and animal
communities, including invertebrates
(for instance, Culp et al.
2011; Poff et al. 2006; Charvet et al. 2000; Dole´dec et al.
2006; Vieira et al. 2006; Magbauna et al. 2010; Menezes
et al. 2010; Statzner and Beche 2010; Ippolito et al. 2012)
.
Increasingly, traits-based approach is also applied to
understand the impacts of pesticides on community
responses of aquatic invertebrate communities
(Liess and
Von Der Ohe 2005; Ippolito et al. 2012; Rubach et al.
2010)
.
So far, traits-based approaches characterizing
invertebrate community responses to pesticides have mostly
treated pesticides impacts in isolation. However, in
multistressor field conditions, pesticides are not the only drivers
of invertebrate community composition. A number of key
environmental factors varying over time and space may
influence the performance of aquatic biota in water systems
around agricultural areas. First, the use of pesticides in the
agricultural fields results in the presence of pesticide
mixtures in surface waters. Therefore, aquatic biota may be
affected by mixtures of pesticides. Second, nutrients
(phosphorus and nitrogen) are commonly applied to the
fields to enhance yields and are often transported to surface
waters in relatively large amounts along with pesticides
(EPA 2012; Tilman et al. 2002)
. Nutrients were shown to
affect the responses of aquatic invertebrates to pesticides in
the laboratory and semi-field conditions
(Alexander et al.
2013; Ieromina et al. 2014a, b)
. Third, other
physicochemical paramete (...truncated)