Filtering it all away – influence of alien species on filter capacity of freshwater systems

Level: Bachelor or Master
Start: Anytime
Project duration: 12 weeks to 6 months
Project form: Field surveys, literature review
Supervision: Frank Collas 
Mail addresses:,

Description of the project:

Globally, freshwater ecosystems are impacted by mainly alien bivalve species (e.g. Quagga mussel, Zebra mussel). Filtration rates of several alien freshwater bivalves are higher compared to the filtration rates of native species. In addition, densities of alien species tend to be higher compared to native species further increasing the discrepancy between filtration capacity of the two species groups.

In order to quantify and predict the influence of introduced alien species on filtration capacity of freshwater bivalves in the river Rhine and Meuse data is needed on filtration rates of freshwater bivalves occurring in the Dutch rivers. Moreover, existing information on known densities in the two river systems is required to fully determine the effect of alien species.

The internship consists of 1) performing a literature review of known filtration rates of freshwater bivalve species, 2) acquisition of freshwater bivalve densities in the rivers Rhine and Meuse and 3) combining the previous databases into a species sensitivity distribution (SSD) that allows to predict filtration capacities of freshwater bivalves.