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Assessing population recovery of aquatic arthropods after pesticide induced mortality using a metapopulation model
Partners:
- Syngenta (Pernille Thorbek, Peter Campbell)
- Bayer CropScience (Eric Bruns)
Contact:
Nika Galic
Paul van den Brink
Aim:
Populations in their natural habitats are frequently affected by various disturbances, both of natural and anthropogenic character. It is resistance to as well as recovery from disturbance that determines the relative stability of populations, communities and ecosystems.
Chemical disturbance is only one of potential disrupting events caused by human activities. Pesticides are used worldwide to increase crop yield and, although becoming very pest-specific, still do affect non-target organisms in areas adjacent to treated crops. What makes certain species recover more successfully than others are specific life-history traits, such as number of reproductive cycles per year (from one to multiple), overall fecundity, dispersal that can be active or passive (via air, land or water), feeding strategies, but also individual sensitivity to the toxicant
affecting them. The last point we consider is the role landscape features have in the recovery process of a certain species, where isolation or connectivity of an affected habitat patch will determine the speed of recolonization.
Approach:
We investigate what combination of life-history traits, landscape characteristics and pesticide application regimes
(as well as mode of action) allows for population recovery by means of an individual-based model (IBM). IBM's look
into the individual organism as the main unit of the population, while population characteristics are obtained through keeping track of intraspecific interactions as well as interactions with the environment.
Example of population recovery in an aerially dispersing species; blue line denotes a system with a single pesticide application, orange line is a 2 pesticide application system. Recovery assumed if populations reach the red line, i.e. the reference population.
More info: www.mastep.wur.nl
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Predicting the response of freshwater arthropods to stress using species traits and stressor mode-of-action, the MASSIVE project
Partners:
- Environment Canada@Canadian Rivers Institute, Canada (Donald Baird)
- Syngenta, Switzerland and UK (Steve Maund, Mick Hamer)
- eawag, Switzerland (Roman Ashauer)
Contact:
Mascha Rubach
Paul van den Brink
Background:
The response of organisms to chemical stressors varies greatly between species and depends on a variety of factors and on the level of organization. The importance of the organism level for Risk Assessment is inevitable as
populations emerge from individual organisms and the organism level facilitates mechanistic understanding of toxicity.
Differences in sensitivity across species towards stressors with specific mode-of-actions are well known, e.g. the sensitivity of freshwater arthropod species towards chlorpyrifos, an acetylcholinesterase inhibiting insecticide varies within a factor of 103. In Environmental Risk Assessment probabilistic tools, such as the Species Sensitivity Distribution (SSD) exist to deal with this variation, however we still lack a systematic and understanding of the underlying reasons for this variation.
Recently, the explanatory and therefore predictive potential of species traits in combination with the mode-of-action
of the stressor has been highlighted and proposed to be used in a framework of trait-based approaches for Environmental Risk
Assessment (TERA).
Aim:
In this project we aim to define and quantify traits, which have predictive potential for arthropod species sensitivity towards the model pesticide chlorpyrifos in relation to the mechanistic processes of toxicity, i.e. the toxicokinetics and toxicodynamics by applying both theoretical, experimental and modeling approaches.
More info: http://www.massivescience.org
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Extrapolation of effects of pesticides on aquatic communities and ecosystems across different exposure patterns
Partners:
- Nuffic ( the Netherlands organization for international cooperation in higher education )
- Water framework directive” research programmes of Dutch Ministry of Agriculture ,Nature, and Food Safety
Contact:
Mazhar Iqbal Zafar
René P.A. Wijngaarden
Ivo Roessink
Gertie Arts
Dick Belgers
Aim:
Contamination of surface water from pesticides typically occurs in single or repeated pulses due to agricultural
run-off, leaching, spray drift, or intermittent urban, and domestic use. The risks of pesticides to aquatic ecosystems are often assessed by performing cosm experiments evaluating a particular exposure regime (e.g. one application),
not necessarily corresponding with the exposure part of risk assessment (e.g. multiple applications). To allow an appropriate linkage of the fate to the effects part of the risk assessment, the results of these cosm experiments ,therefore, sometimes need extrapolation to a different exposure pattern than the one that is evaluated in the cosm experiment itself . This PhD project aims to establish empirical, experimental and modelling approaches to extrapolate from one type of exposure pattern to the other.
Approach:
Empirical and Experimental approach.
Results:
Results of comparison of Single Versus Multiple applications and Acute Versus Chronic exposures of pesticides using PERPEST “Data base “ on arthropod species.
TV-TOX Results:
Results for Time-variable exposure regimes of insecticide CPF (Chlorpyrifos) towards Freshwater invertebrate communities in outdoor microcosms.
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