COMBINING DATADRIVEN METHODS AND LAB STUDIES TO ANALYZE THE ECOLOGY OF DIKEROGAMMARUS VILLOSUS
Peter Boets, Koen Lock, Peter Goethals
Last modified: 2008-09-14
Invasive species are considered as an important component in the decline of diversity and abundance of species in freshwater ecosystems. Besides its ecological impact invasive species are considered to cause worldwide economical damage. One of these invasive species is the Ponto-Caspian invader Dikerogammarus villosus which has since the beginning of the 1990s, as result of the opening of the Main-Danube canal, invaded most parts of Europe. In this study the impact of D. villosus on macroinvertebrate communities in rivers was investigated by means of laboratory experiments. We also tried to predict the presence of D. villosus by means of decision trees and an available dataset. The results from the experiments are an indication for the predatory behaviour of D. villosus towards indigenous en non-indigenous species. Small and slow as well as large and fast species were predated or showed marks of predation. It seems that the complexity of the habitat as well as the interaction between species plays a crucial role in the predation of other macroinvertebrates. Therefore communities can experience a different impact as result of prey-selection by D. villosus. Based on a decision tree D. villosus seems to be mostly present in rivers with a non-natural bank structure and with ion-poor water containing sufficient oxygen. This species is known to be widespread both in natural and non natural watercourses. Based on the present results and earlier studies there can be expected that this species will cause a further decline in the diversity of freshwater ecosystems. Perhaps an efficient water management can be the first step to reduce spread of potential new invaders.