The effects of invasive organisms on an aquatic ecosystem will depend, in part, on the distribution and biomass of the invasive organisms in the system. Here we present the results of a lake-wide survey of the distribution of invasive dreissenid mussels (Dreissena spp.) in Lake Simcoe, Ontario and discuss some of the factors that shape their distribution pattern in the lake. Dreissenid biomass averaged 27.2g shell-free dry mass (SFDM)/m2 in the main basin of Lake Simcoe and 12.4g SFDM/m2 in macrophyte-dominated Cook's Bay. We argue that water movement is an important determinant of dreissenid distribution, both through catastrophic disturbance in shallow water and through non-catastrophic effects on substrate distribution and possibly food supply rates. In areas of dense macrophyte growth, mussel abundance was shown to be associated with that of preferred macrophyte taxa, in particular with that of Ceratophyllum demersum. We used the results of our survey and the relationships between environmental variables and dreissenid biomass to estimate the total biomass of dreissenids in Lake Simcoe: 11,897 tonnes SFDM. This study contributes to the understanding of dreissenid ecology and provides a baseline for future studies of dreissenid distribution and impacts in Lake Simcoe.
Bibliographical noteFunding Information:
The authors would like to thank Adam Houben, Zing Ying Ho, Jessica Pang and Andrew Bolyachevets for their invaluable assistance in the field and in the lab. We would also like to thank Dr. Joelle Young and two anonymous reviewers whose comments helped considerably in improving this manuscript. Funding for this project was provided by the Ontario Ministry of the Environment through a Best in Science grant to SJ Guildford.
Copyright 2011 Elsevier B.V., All rights reserved.
- Benthic ecology
- Distribution patterns
- Dreissenid mussels
- Lake Simcoe