Macquarie University

Faculty Member, Biological Sciences

Lecturer

About

My research investigates natural and human-mediated processes that control coastal biodiversity and its important ecosystem functions. I use manipulative field experiments to investigate effects of global and local change, often producing results that could not have been predicted using theoretical or modelling approaches.

Brown food webs

My recent research has considered how detrital heterogeneity influences the important ‘brown’ food webs supported by this resource. Most food web models treat the diverse sources of detritus that fuel coastal systems as a homogeneous resource. Recently, I showed that not only do detrital sources vary markedly in their value to consumers, but when mixed they produce non-additive effects that are not easily predicted from their individual components (Bishop & Kelaher 2008, Oikos). These results will revolutionise the way detritus is treated in food-web models.

Green food webs

I am also interested in primary producers and the ecosystem services they support. I recently documented changes in seagrass species composition and function at a present day zone of biogeographic overlap (Micheli, Bishop et al. 2008, Ecol Monogr). My empirical test of resource- and ratio-dependent consumer models, the first in an estuarine system, has improved understanding of effects of moderate nutrient enrichment that result from stimulation of primary productivity (Bishop et al. 2006, Oceologia). I showed that whereas large nutrient inputs frequently induce mortality of invertebrates and fish, smaller inputs may in fact enhance biomass of all trophic levels. These results are being used in catchment management.

Oysters

A collaborative project with NSW Department of Primary Industries and Hornsby Shire Council is investigating the ecological impacts of QX oyster disease. Australian oysters support a valuable food industry and promote healthy estuaries by providing vital ecosystem services. QX disease is economically and environmentally important because it causes mass mortality of Sydney Rock oysters. To restore oyster production, managers are currently trialling triploid Pacific Oysters and QX-resistant Sydney Rocky oysters in QX-affected estuaries. We are investigating how these strategies influence wild oyster populations and what this might mean for provision of ecosystem services.