Krijn Trimbos is an environmental biologist and molecular ecologist driven by improving biodiversity assessments through the application of novel molecular tools, to ultimately create a better understanding of how humans impact the environment. He is currently head of the department of Environmental Biology within the Institute of Environmental Sciences of Leiden University.

More information about Krijn Trimbos

Professional experience

Krijn graduated in 2007 from Leiden University with a doctorate in Biology. His studies pushed him towards two specialization trajectories, one focused on Medical Biology and one on Environmental Science. He conducted two internships within the field of Medical Biology revolving around immunological B and T-cell responses against Human Papilloma Virus both in The Netherlands and in Indonesia (Bali). During his last internship he worked on breeding success differences of Skylarks between organic and conventional arable farms. 

He started a PhD in 2007 at The Institute of Environmental Science (CML) Leiden University. His PhD topic combined the best of both study directions, lab and ecological field work within an Environmental Science scope, and focused on genetic patterns of Black-tailed Godwit populations and their implications for conservation. The aim was to investigate long term population dynamic processes in Black-tailed Godwit populations resulting from habitat fragmentation on three different spatial scales by using genetic tools. He demonstrated that egg shell membranes provide a good alternative DNA source compared to blood for these kind of studies. Additionally, he showed that habitat fragmentation, although geographically visible, has not yet lead to genetic differences between Dutch breeding populations yet. On a global scale three genetically distinct groups were recognized as subspecies, but again within these subspecies populations clear fragmentation affects could not be detected. Finally, he identified fitness correlates within Dutch Godwit breeding populations demonstrating that certain mutations in chicks lead to a higher body mass and return rate. Research entailed close collaboration with the Animal Ecology group of Theunis Piersma, University of Groningen and running three field seasons in South-West Friesland as a part of the long term demographic research that was conducted there by that group. 

After 2011 he continued his career at one of the Dutch provincial NGO’s (Landschap Noord-Holland) where he was project leader meadow bird protection for three years, which involved coordination, training and education of volunteer meadow bird protectors and writing and executing research projects involving meadow bird conservation. 

In 2014 Krijn returned to the academic world as University Lecturer at the Institute of Environmental Science (CML) where he got involved as a teacher and course coordinator in different teaching programs (Institute of Biology, Leiden University College and at CML) at Leiden University spanning multiple different courses and disciplines; field, sustainability, environmental science courses both on a BSc and MSc level. Since 2017 he has been appointed as Assistant Professor at Institute of Environmental Sciences during which he setup a successful and expanding research line in Environmental DNA (eDNA). Since 2022 he became head of the department of Environmental Biology within the Institute of Environmental Sciences of Leiden University.         

Research topic

In his current research Krijn aims to improve biodiversity assessments through the application of novel molecular tools. Where his work originally focused more on increasing our understanding on population dynamic processes of single species through the usage of genetic techniques, his research has moved towards two slightly different focal points:   

1. Expanding the eDNA toolbox so that it can have a broader use in ecological and environmental science related questions. 
2. Applying these eDNA tools to ultimately get a better understanding into ecological changes underlying human impacts on the environment.

In recent years his research in regards to focal point 1 has focused on abundance/eDNA concentration correlations for exoskeleton shedding invertebrates and bivalves, seed abundances in mouse feces through eDNA analysis to improve risk assessment methods, eDNA methylation and deriving age classes thereof, understanding detection probability of difficult to detect aquatic species and decreasing false positive estimates of species presence. His recent eDNA application studies have concentrated on the impacts of agricultural stressors & invasive species on aquatic communities. Additionally, he has studied the diet of African lions and how that might relate to National Park management. By collaborating closely with societal partners such as Waterboards, Chemical companies, Universities (of applied science), Naturalis Biodiversity Center, NGO’s, KWS, governments and many others Krijn intents to ensure high societal impact with his research. His future research will focus on studying plant pollinator networks using eDNA and the impact of additional agricultural and other stressors on soil and aquatic communities.          
 

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