Fish are of great significance in view of the central role they play in aquatic ecosystems and also as providers of high-quality food. Especially in the current period of climate change and strongly increasing world population, fish is gaining more and more importance as protein resource. Additionally fish play a decisive role in life cycles of a multitude of parasites, as they function as intermediate as well as final hosts. Thus they often harbor a wide range of parasite species including high intensities of infection and are therefore excellent study organisms in all aspects of basic and applied parasitology and comprise biological interests like parasite-host interactions but also social and economic concerns in agriculture or medicine.
In the last century, due to globalization and especially the rise of shipping traffic, around 200 aquatic species, e.g. fish, crustacean and molluscs, get spread to new habitats in Germany and Europe. Native species communities have to struggle with these invaders, which show higher reproduction rates, different environmental tolerance and aggression as well as mutual predation and therefore compete for prey and habitat. Thus entire eco-systems are often threatened including huge changes in parasite fauna. Parasitized non-indigenous species can have different effects for the host and the local parasite fauna: 1) loss of the invaders original parasite load, 2) introduction of new parasite species with the invader, 3) invasive species can successfully act as intermediate hosts or vectors for existing parasites or diseases, 4) shift and/or loss of local parasite species, if the invader replaces local host species, but cannot act as intermediate or definitive host in the parasite life cycles. This working group mainly studies the risk of establishment of aquatic invasive species with a focus on parasite diversity and new parasite-host interactions.
Over 32.700 different fish species have been described throughout the world, of which about half live either in sea (marine) or freshwater habitats. Parasitic infestation of fish intended for human consumption has long been recognized as a problem. Especially in the marine aquatic domain, the state of knowledge concerning the global diversity of medically relevant species is very inhomogeneous. As a response to this, researchers of the working group “Aquatic Parasitology" are investigating the wide range of medically significant parasites, their distribution and population dynamics, their ecology, genetics and life-cycle strategies, as well as the effects they may have on human health. In order to be able to obtain information about the zoogeography of zoonotic parasites and the likelihood of human parasitic infections in certain regions, we combine various aspects of existing methods for calculating distribution areas within new and comprehensive approache.