research
population biology | spatial ecology | wildlife disease | conservation | mathematical modeling
CURRENT PROJECTS
Migration and parasitism in the changing Canadian Arctic
I am beginning some new work developing models to understand how migration and parasitism interact to affect wildlife populations. This research will be applied to caribou populations in the Canadian Arctic, whose migration patterns and parasite dynamics are being affected by climate and land-use changes.
Collaborators: Susan Kutz, Péter Molnár, Mark Lewis, Juliette Bouhours
Key publications: Peacock et al. 2018 Theor Pop Biol
Impacts of sea lice on wild salmon
and associations with salmon aquaculture
How do sea louse parasites affect wild salmon in Pacific Canada? The extent to which salmon farms spread lice to wild juvenile salmon has been a subject of some debate, making this an important conservation question. Despite a decade of successful management of sea lice on salmon farms, in 2015 we observed an outbreak on juvenile wild salmon, highlighting that the problem of sea lice is far from solved.
Collaborators: Martin Krkosek, Mark Lewis, Andrew W Bateman, Brendan Connors and others ...
Key publications: Peacock et al. 2013 Ecol Appl, Bateman, Peacock, et al. 2016 CJFAS
Population ecology of host-parasite systems
and effects of predation and migration
There is a rich history of population models for host-parasite systems, spurred by the seminal work of Anderson and May in the 1970s. I am interested in understanding how ecological processes - such as predation and migration - affect host-parasite dynamics. The results are sometimes unexpected! For example, we found that if parasites affect species-selective predation, then some hosts may benefit from low levels of infection. Similarly, migration - although a costly undertaking - may improve population health via migratory escape from infected hotspots or migratory culling of infected individuals.
Collaborators: Peter Molnar, Mark Lewis, Martin Krkosek, Brendan Connors
Related publications: Peacock et al. 2014 Proc Roy Soc B, Krkosek et al. 2011 Ecol Appl, Peacock et al. 2015 Ecosphere
PAST PROJECTS
The dynamics of coupled populations
Unexpected outcomes of population control
Understanding the properties of interacting human and natural systems is important for successful conservation outcomes. For example, the success of aquaculture depends on our ability to manage pathogens and maintain a healthy environment for farmed and wild fish. We used a simple model to understand how threshold control treatments of nusiance populations (e.g., parasites) can change when populations are connected by dispersal. A relatively simple model resulted in surprisingly complex dyanmics! For aquaculture, the interaction between farm management and natural pathogen dynamics, such as dispersal among farms, may lead to unpredictable dynamics that undermine our ability to maintain a healthy environment for both farmed and wild salmon.
Collaborators: Andrew Bateman, Martin Krkosek, Mark Lewis
Key publication: Peacock et al. 2016 Theoretical Ecology
Spatial spread of invasive species
and the buoyant dispersal of Codium fragile
The invasive seaweed Codium fragile may be blown along the surface as buoyant propagules, speeding its spread along the east coast of North America. Codium fragments can photosynthesize, producing oxygen that keeps them afloat for long distances before they sink and can establish new plants. This mode of transportation has largely been ignored, but may be key to understanding how far and how fast Codium can spread. To understand how sunlight and wind affect the secondary spread of this invader, we built a mechanistic model of this process.
Collaborators: Karine Gagnon, Yu Jin, Mark Lewis.
Key publication: Gagnon et al. 2015 Ecological Modelling