Decline of Dreissena polymorpha in the River Moselle: biotic and abiotic key factors involved in dynamics of invasive species
Bachmann, V.; Beisel, J. N.; Usseglio-Polatera, P.; Moreteau, J. C.
published: Apr 27, 2001
ArtNo. ESP141015102011, Price: 29.00 €
Macroinvertebrate communities sampled in 1994, 1995 and 1996 showed that three invasive exotic species (Dreissena polymorpha, Corophium curvispinum and Corbicula fluminalis) were well established and coexisted in the River Moselle. Results highlighted a decline of the zebra mussel population, the oldest invader considered, between 1994 and 1996. Benthic densities decreased. The recruitment of juveniles was unsuccessful and population was clearly ageing over the considered period. These results were confirmed by a decline of the veliger density (reproduction capacity) between 1994 and 1998. Biotic and abiotic factors which have probably influenced the zebra mussel population dynamics are discussed. The recent establishment of C. curvispinum in the same mesohabitat type and the massive development of Corbiculidae suggested a possible competition for habitat and/or food between these invasive species. A first abiotic factor was the hydrological regime of 1994 and 1995, which was particularly high for the 1992-1998 period. It may have removed the substratum and then favoured the settlement of an opportunistic species like C. curvispinum with a high reproductive output and a reproduction period early in the year. A second abiotic factor was the physicochemical water quality of the River Moselle. In 1993 and 1994 the high chlorophyll-a concentration probably favoured the incubation of C. curvispinum, and in 1994 the pH did not reach an optimal value for the survival of D. polymorpha veligers. Our results describe key factors for understanding the population dynamics of invasive species in regard to environmental changes and processes involved in future ecosystem invasions.