Vanessa Kunz, PhD
Before I came to the MGU, I did my PhD on the impact of anthropogenic modifications on in-stream nutrient cycling. Overall I’m interested in investigate how humans change aquatic (especially lotic) environments.
My current research focus at MGU: Active distribution of invasive fishes (esp. ponto-caspian gobies) in river-networks and the role of man-made constructions (weirs, hydro-power plants etc)
Restoring ecologically valuable spawning grounds and habitats in rivers and allowing longitudinal migration of fish and other aquatic species is currently a priority topic in river management and the basis to prevent the extinction of many endangered fish-species. International regulations and programs like “Salmon 2020” have already achieved improved fish passes at many hydro-power-plants in the Rhine and its tributaries
However, providing unobstructed hydro-ecological passage, also facilitates the penetration of invasive species into beforehand protected habitats.
My research investigates potential adverse effects such river restoration measures can have because of the enhanced distribution of invasive fish species.
The propagation of invasive round goby neogobius melanostomus in the High-Rhine and tributaries of ecological importance serves as a case study to address the following questions:
- Are common fish-ladders (at hydropower plants, weirs etc) passable to round gobies?
- Does the removal of sills in the Wiese (a tributary of the Rhine in the Basel region, CH) promote the upstream migration of round gobies?
Ethohydraulic experiments are supplementing direct field observations and deliver results which can be transferred to other locations.
Based on the achieved scientific findings I want to develop technologies that
- Selectively prevent the passage of round gobies through fish ladders by physical and acoustical barriers
- Expel round gobies (known to feed on spawn and larvae) from spawning grounds of native fishes or other ecologically/economically important sites
My research therefore relies on close collaboration with university and non-university colleagues from multiple-disciplines. Amongst others: The hydro-power plant operator, the local and federal authorities, fishery authorities, hydrologists, …
Kunz, J.V., Hensley, R., Brase, L., Borchardt, D., Rode, M. (2017) „High frequency measurements of reach scale nitrogen uptake in a 4th order river with contrasting hydromorphology and variable water chemistry (Weiße Elster, Germany)“, Water Resources Research, 53, doi:10.1002/2016WR019355.
Kunz, J.V., Annable, M.D., Cho, J., Von Tümpling, W., Hatfield, K., Rao, S., Borchardt, D., Rode, M. (2017) „Quantifying nutrient fluxes with a new Hyporheic Passive Flux Meter (HPFM)“, Biogeoscience, 14, 631-649, doi:doi:10.5194/bg-14-631-2017.
Kunz, J.V., Rode, M., Annable, M.D., Rao, S., Borchardt, D. „Hyporheic passive flux meter reveal unexpected source-sink behavior for nitrogen in an anthropologically modified stream (Holtemme River, Germany)“, submitted to Water Resources Research.