Epigenetic response to chemicals?
Transgenerational epigenetic & phenotypic response of aquatic invertebrates
Fungicide pyrimethanil
Effects on species & communities at different temperature / seasons
Effects on communities in different ecoregions
Herbicide metazachlor
Effects on aquatic macrophytes in differently complex systems
Epigenetic response to chemicals?
Numerous chemical pollutants such as the fungicide vinclozolin and the phytohormone genisteine are reported to trigger epigenetic modifications in vertebrates. With focus on invertebrates, only few epigenetic studies exist. We detected for the first time the existence and age-dependence of DNA methylation in the snail Physella acuta. The postulated relationship between vinclozolin phenotype and epitype was however not shown in the transgeneration study with the freshwater snail. In contrast in the transgeneration study with the Asian tiger mosquito Aedes albopictus (larval stage is aquatic), the altered DNA methylation level after vinclozolin and genistein exposure was associated with an decreased insecticide susceptibility. Certainly, further research is needed to evaluate the importance of potential epigenetic modes of action of pesticides and other chemicals for the adaptation of species and ecosystem health.
Fungicide pyrimethanil: Effects on species & communities at different temperature / seasons
The fungicide pyrimethanil is frequently used as plant protection product in vineyards, apple orchards and for other crops such as strawberries and citrus fruits. The fungicide regularly enters surface waters via run-off, spray drift and wastewater discharges due to inefficient retention capacities of wastewater treatment plants. How will the combination of fungicide pollution and climate-induced changes impact terrestrial and aquatic key species and biodiversity, and thus the ecosystem functions in future?
The projects AdaMus and Multiple stressors aimed to understand the prospective ecosystem stress responses and adaptive potential of species and communities to multiple stressors to provide reliable predictions of future developments in our environment. The fungicide pyrimethanil was used as model substance for investigating the combined effects of pesticides & climate. Our AdaMus consortium consisted of academics (Goethe University and Senckenberg German Centre for Marine Biodiversity Research) and small-to-medium enterprises (Mesocosm GmbH and ECT Oekotoxikologie GmbH).
In the project Multiple stressors and the subproject AdaMus AQUA, we investigated the effects of pyrimethanil on aquatic non-target organisms and communities under different microclimatic conditions in the laboratory and in artificial ecosystems (mesocosms). Daphnids (Daphnia pulex), aquatic insects (Chironomus riparius, Chaoborus flavicans) and snails (Physella acuta, Physa fontinalis) were chronically exposed to low doses of pyrimethanil at different temperature scenarios to analyse their population dynamics over multiple generations in presence of multiple stressors under controlled laboratory conditions. This information was helpful to understand the biological processes observed in the mesocosm settings. Next to pyrimethanil exposure and thermal stress, alien species or kairomones of predator species were introduced into bioassays to test for biotic interactions under multiple stress conditions.
Impressions of the mesocosm work in the botanical garden Frankfurt am Main, Germany:
Fungicide pyrimethanil: Effects in different ecoregions
The project Pesticlimat compared the impact of the model fungicide pyrimethanil on artificial water systems (mesocosms) in three distinct climate regions (subtropical, warm and cold temperate; Brazil, Portugal and Germany). Pesticlimat was coordinated by Dr. Ruth Müller, Dr. Cândida Shinn and Prof. Dr. Rui Ribiero from the University of Coimbra, and Prof. Dr. Evaldo Luiz Gaeta Espindola from the University São Paulo.
Herbicide metazachlor: Effects on aquatic macrophytes
The effects of the herbicide metazachlor on the macrophytes Myriophyllum spicatum, Ceratophyllum demersum and two duckweed species were tested in lotic and lentic mesocosms for aquatic envrionmental risk assessment of the herbicide at tier III. The artificial stream and pond system of the German Federal Environment Agency’s field station in Berlin-Marienfelde is one of the largest and most modern mesocosm systems in the world. The gained results were used to set the environmental quality standard for metazachlor in Switzerland.
