Project Objectives
- Develop sensitive and reliable methods to detect Proliferative Kidney Disease (PKD) in river water using environmental DNA (eDNA).
- Evaluate ecological factors that influence detection, such as seasonal parasite shedding and bryozoan distribution.
- Create spatio‑temporal detection probability maps to guide monitoring strategies.
- Produce practical recommendations and protocols for water‑based PKD surveillance.
- Train cantonal and federal partners to support nationwide adoption of non‑lethal monitoring.
3Rs Impact
- Replaces lethal fish sampling with a fully non‑invasive, water‑based monitoring method.
- Eliminates the need to euthanise thousands of pre‑reproductive brown trout for PKD surveillance.
- Avoids electrofishing‑related stress, injury, and habitat disturbance for both target and non‑target species.
- Enables broader, more efficient monitoring across Swiss rivers without additional animal use.
Background
Proliferative Kidney Disease (PKD) is a serious parasitic disease affecting brown trout populations in Switzerland and across Europe. Monitoring PKD currently requires electrofishing and euthanising large numbers of potentially healthy fish to test their organs for infection. Since 2000, more than 15,500 pre‑reproductive brown trout have been culled at the Institute for Fish and Wildlife Health alone for PKD surveillance. This approach is labour‑intensive, stressful for fish, and contributes to habitat disturbance during sampling.
Environmental DNA (eDNA) offers a promising non‑lethal alternative. Organisms release genetic material into their surroundings, and this DNA can be captured from water samples and analysed to detect pathogens. eDNA methods have already shown success in monitoring waterborne diseases in other aquatic species, but they have not yet been fully validated for PKD.
This project aims to establish a sensitive, reliable, and field‑ready eDNA‑based method for detecting the PKD parasite in Swiss rivers. By optimising sampling and DNA detection techniques, studying ecological factors that influence detection, and validating the method across multiple river systems, the team will generate practical tools and guidance for authorities. The ultimate goal is to replace lethal monitoring with a humane, efficient, and scalable approach.
