Our research interests fall into several interconnected categories that revolve around the basic

question of what influences biodiversity and ecosystem function at different spatial scales:

1) Invasive Species

The effects of invasive species on aquatic communities is predicted to be particularly severe, altering native species biodiversity, with largely unknown consequences for the functioning of the ecosystem.  Previous lab research has assessed the effect of Bythotrephes longimanus (right), a predatory planktonic invertebrate on native plankton communities using experiments and landscape surveys.   Other lab research has examined the role of the aquarium trade in introducing non-native species, as well as potential consequences of invasion for conservation of endangered native fishes.

2) Climate Change

The effects of climate change are expected to be most pronounced in high altitude, high latitude, and boreal regions.  Using a combination of field survey and experimental techniques, our research has examined the effects of climate on freshwater lake and pond plankton communities in these regions.  As a result of their small size and rapid reproduction, organisms like phytoplankton and zooplankton can be the 'canary in the coalmine' and provide invaluable information about the effects of a warmer climate, especially in regions which have already warmed considerably in the past few decades.

3) Spatial Ecology

In recent years, there has been increasing recognition of the role that spatial dynamics play in the interpretation of ecological patterns and the need to incorporate space into ecological studies. Observations of patterns at one scale may be the result of processes occurring at different spatial and temporal scales. Our research uses tools from landscape ecology to assess the importance of spatial scale in structuring biotic communities in lakes and rivers.  The figure on the right is data collected by the Ontario Ministry of Natural Resources to test some general hypotheses regarding how differing spatial scales can structure both the abundance and productivity of freshwater fish communities.

4) Freshwater Conservation

Many freshwater ecosystems are threatened by human activities.  This is particularly true in the Lower Colorado River basin, where flow modifications, river regulation, non-native species, and land use change have had significant effects on a highly threatened yet highly endemic native fish community.  Preserving species diversity in these regions is challenged by the lack of species distribution information and a rigorous quantitative conservation framework.  Lab research has used species distribution modeling and optimization algorithms to identify areas that are priorities for conservation for native fishes in the Lower Colorado River basin.