Department Aquatic Ecology

Ecology and diversity of stickleback in Lake Constance

This project is part of the international research project SeeWandel (additional information can be found at SeeWandel and
Over the past century, Lake Constance has experienced multiple environmental changes that could affect endemic fish communities, including changes in nutrient loading, climate warming, introductions of new fish and invertebrate species, changes in the seasonality of plankton dynamics and composition, and changes in habitat structure. A recent survey of fish communities in Lake Constance (Projet Lac) revealed a very high abundance and wide distribution of stickleback within the lake. This hyper-abundance of stickleback in Lake Constance is both concerning, because of the potential for competitive interactions with Whitefish populations, and perplexing, because stickleback rarely reach such high abundances in large lakes.

To explain the dominance of stickleback in Lake Constance we require a better understanding of (i) the foraging adaptations of stickleback that might influence the outcome of competitive interactions with Whitefish, (ii) the influence of other non-fish species (e.g. mussels, macrophytes) on stickleback performance (e.g. growth), (iii) the spatial structure of the stickleback breeding habitats, and (iv) the association of system-wide population structure with major habitats (e.g. littoral macrophytes, stream inlets, sand and gravel beaches).

To address these main points of uncertainty, we are using a combination of field surveys, laboratory and pond experiments, and genetic analyses. These are designed to improve our understanding about why stickleback in Lake Constance are able to invade in such unusually high abundance into habitats that stickleback elsewhere in Switzerland fail to invade.


Publications can be found at: SeeWandel publications