Research

I am an ecologist interested in the impact of global change on trophic interactions and ecosystem functioning. I am currently a postdoctoral fellow based at Imperial College London, working with Prof. Guy Woodward. 

Previously I was at the University of Pretoria, funded by the Centre for Invasion Biology (Stellenbosch University; http://academic.sun.ac.za/cib/)
                              
My research broadly focuses on two areas of interest; the impact of global environmental change in freshwater ecosystems and the application of stable isotope analysis to answer ecological questions. Below I have outlined some current projects:

Global warming in freshwater ecosystems

Climate change is causing temperatures around the world to increase with negative implications for many

species. At an individual level warming can cause changes in growth rates and shifts in range. However, we need more information on how whole communities of interacting

species (i.e. food webs) are altered by temperature shifts. I am a postdoc on 'The Ring of Fire Project' which aims to quantify the gene-to-ecosystem impacts of warming with field sites across the Arctic. 



Multiple stressors in freshwater ecosystems

The acceleration of global change highlights the increasing need to quantify the nature of interactions among multiple stressors affecting biodiversity and ecological processes across a broad range of ecosystems. 
Freshwater ecosystems are particularly vulnerable to global change; a recent WWF report found average population declines of 76% among freshwater species since 1970 compared to 39% in terrestrial and marine species.  

I use multiple approaches, including meta-analyses, laboratory experiments and field based projects, to explore the combined impacts of stressors in freshwaters.


Stable isotopes and food webs

Stable isotope analysis is a valuable tool to infer trophic links and characterise food web structure because the isotope signature of the body tissue of a consumer will reflect that of what it has eaten (essentially, ‘you are what you eat’). I am involve in a number of projects using isotopes including:
  • The diet of invasive fish in South Africa.
  • Food web structure in the Zambezi and Okavango Rivers, Namibia. 
  • Trophic diversity across a temperature gradient in Kamchatka, Russia

Invasive species 

Predicting the impacts of biological invasions on native communities is increasingly important in our changing world. I am involved in projects which aim to quantify the impacts of riparian and freshwater invasions on food webs. A lot of my current work is based in South Africa, with previous field sites in Kenya. 


Hiking to the field sites in Svalbard


Geothermal region in Iceland


Insect emergence traps in South Africa


Invasive red swamp crayfish in Kenya 


Fieldwork on the River Malewa, Kenya