My research concerns specifically the foraging and diving behaviour of marine predators
and more generally how this can inform conservation planning in the ocean.
Marine predator foraging ecology
Work on predator foraging often relies on inference from dive profiles. Using a miniature video camera
(developed by Wild Insight Ltd, Ely,
Cambridgeshire, UK) attached to the animal we can view the foraging space of a diving animal and test
previously used proxies for foraging behaviour. The initial results from the digital video camera
have been promising (for more details see publications). These images can help provide context for our information on the diving behaviour of these animals, and allow us to examine their behavioural decision-making in terms of when it is no longer profitable to continue foraging, and how often and how deep to dive in search of food. They also allow us to identify diving signatures which appear to indicate the presence of high prey concentrations. The identification of foraging areas and assessment of the stability of these over time and space enable us to investigate variability in foraging success
and the criteria driving this (whether anthropogenically or environmentally induced)
The mechanisms allowing marine mammals to avoid problems associated with diving to depth are still only
partially understood. Recent deaths of beaked whales associated with sonar exposure appear to be due to
decompression sickness. I am interested in how problems such as shallow-water blackout and decompression
sickness are avoided, and use modelling approaches to determine risk based on dive profiles.
Conservation planning and marine protected areas
An ecosystem-approach is widely advocated in conservation planning but ecosystem modelling approaches,
despite their sophistication, often suffer from a lack of source data or inherent uncertainties. An
alternative is to use spatially explicit management. I am interested in the application of such marine
reserve areas to higher predators. The relationship of "foraging footprints" to surrounding
oceanographic conditions, and the consistency of these in time and space will enable us to begin to
map the more productive ocean regions. The identification of particular oceanic hotspots may help in
establishing protected areas of ocean to function in the same manner as "wilderness"
areas on land.
My PhD research was on the foraging ecology of a population of northern bottlenose whales that are found in the Gully, a submarine canyon off the coast of eastern Canada. This area represents a distributional hotspot for this population. Different aspects of my PhD investigated the diet, distribution, diving behaviour, movements, and acoustics of these whales. Consideration of the Gully as a marine protected area led to a strong application of our research there in assessment of potential boundaries and
conservation priorities for the area. Link to page detailing my PhD research at Dalhousie University.
After my PhD, I spent some time working in Hawaii with Dr Robin Baird studying the foraging behaviour of pantropical spotted dolphins and conducting a population assessment of local bottlenose dolphins. We were also funded by the Hawaiian Islands National Marine Sanctuary to study the diving and subsurface behaviour of humpback whales in their breeding grounds [further details].
Working for the British Antarctic Survey, I was involved with the development of new techniques to record environmental and oceanographic data. In particular I investigated the potential for incorporating new sensors into datalogging tags. I pursued two new avenues for this - using digital cameras to record the
prey-field of diving animals (see above), and incorporating conductivity sensors into
conventional dataloggers to record salinity information (for more details see publications). We tested these on Antarctic fur seals at Bird Island, South Georgia.