Environment
From understanding human impacts on biodiversity to conducting environmental assessments, this page features eDNA research with a core environmental focus.
Water Quality
The state of water quality around the world is a matter of growing concern. Despite significant advancements in environmental awareness and regulations, many regions continue to face challenges related to deteriorating water quality. Biomonitoring is a valuable and widely used tool for assessing the health and quality of aquatic ecosystems. However, traditional ways of monitoring are often time consuming, invasive in nature and prone to observer or identification bias thereby severely limiting the number of samples that can be taken in space and time. This in turn hampers our understanding of how freshwater communities are affected by human activities and what this means for water quality. Through the usage of eDNA, which is less invasive and far less time consuming we have been able to increase our spatial and temporal sampling efforts significantly.
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Currently, we are using eDNA as a means of biomonitoring in several projects where the aim is to study the effects of human activities, such as agricultural stressors (pesticides), introduction of non-native species (Dreissena burgensis) and plastic pollution on aquatic communities and what this entails for water quality.
Want more information? Check out this publication from Dr. K. Beentjes: Beentjes K.K, Barmentlo S.H., Cieraad E., Schilthuizen M., Hoorn B.B. van der, Speksnijder A.G.C.L & Trimbos K.B. (2022), Environmental DNA metabarcoding reveals comparable responses to agricultural stressors on different trophic levels of a freshwater community, Molecular Ecology 31(5): 1430-1443. https://doi.org/10.1111/mec.16326.
Affiliated members: Dr K. Trimbos, Dr. K. Beentjes, K. Kagzi, M. van der Plas
Impact of Urbanization on Beach Meiofauna
Sandy beaches are globally important ecosystems for coastal protection and recreation, but also harbor a unique biodiversity. Despite their ecological importance and popularity for human activities, beach ecosystems are widely understudied. We use environmental DNA metabarcoding of sediment samples taken from beaches along the Dutch coast to assess the impact of urbanization – tourism, beach driving, buildings on the beach, loss of dunes – on beach meiofauna communities. Meiofauna, which consists of animals smaller than 1mm, is the most diverse group of animals inhabiting sandy beaches. Meiofauna are known for their sensitivity to environmental changes, which makes them good bioindicators. In this project, we combine field work, taxonomic work to identify species, reference DNA barcoding, and high throughput metabarcoding of hundreds of sediment samples to improve understanding of beach ecosystems and their biodiversity, and facilitate the use of environmental DNA for beach monitoring.
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Affiliated Members: Dr. J. Macher
Micro and Nano Plastics
Plastic pollution has been studied widely over the last few decades, mostly focusing on macro plastics and to a lesser extend micro plastics. However, as plastic degrades, macro plastics end up as micro, and eventually nano plastics. While there has been research on the ecological effects of micro plastics, studying the effects of nano plastics has proven to be difficult, among others due to the chemical composition of the particles which make it hard to distinguish them from other (carbon) components. However, due to recent developments, it has become more convenient to track these particles, making it possible to thoroughly study the fate and effects of micro and nano plastic particles in a system.
By using our mesocosm facility in Leiden, we combine traditional sampling techniques with eDNA sampling to create a complete picture of the effects of micro and nano plastic particles under controlled, realistic conditions. Using eDNA metabarcoding, we characterize how invertebrate as well as microbial community composition changes when exposed to different sizes of ecologically realistic concentrations of micro and nano plastic particles. Among others, we look at the changes in community composition over time after exposure to the particles based on the eDNA data as well as traditionally obtained data, the fate of the particles, insect emergence, decomposition rate and microbial activity.
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Affiliated Members: M. van der Plas
