Katrine Turgeon

“Barbados.” Katrine Turgeon cannot say the word without a sigh that draws out that final surf-like sibilant. Having left her tropical reef-diving days behind – for now – she’s begun a post-doc position this year in U of G’s Department of Integrative Biology.

Not that she’s a stranger to Canadian winters. Turgeon grew up in Quebec and studied ecology at the University of Sherbrooke before doing grad degrees in biology at the Université du Québec à Trois-Rivières and at McGill University in Montreal.

Last summer, she arrived in Guelph to study aquatic ecology and fisheries with Profs. John Fryxell and Tom Nudds. Those projects have her looking at two kinds of ecosystems – one artificial, one natural – that appear rather different from those Caribbean coral reefs.

One study takes place in the new limnotron facility housed at U of G’s Biodiversity Institute of Ontario. There, six upright stainless steel tanks allow ecologists such as Fryxell to model aquatic population and community dynamics and study how organisms interact and move.

Last summer Turgeon took part in the first tests of the facility. She used invertebrates called rotifers as well as algae to see how population densities change with differing water volumes and other variables such as nutrient levels.

They’re now beginning a new round of experiments to see how predation affects population stability of these organisms. She says it’s a worthwhile study topic that came up accidentally after one of the tanks was contaminated by freshwater creatures called ostracods.

When these seed shrimps began feasting on the tank occupants, the researchers saw an opportunity to look at predation in their artificial environment. Allowing these kinds of studies is the purpose of the limnotron, whose modified beer vats allow scientists to test anything from the effects of global warming on ecosystems to the introduction of invasive species in complex food webs.

“There are a lot of cool things out there, but it’s hard to test things in the real world, there are so many contributing factors,” says Turgeon. She says controlling those factors in the limnotron will help to improve ecological theory.

Fryxell recently has attracted headlines not for aquatic research but for his studies of migrating wildebeest in Africa. The same ecological ideas apply in water or on land, he says: “There are strong similarities in many spatial processes affecting animal populations, whether one is talking about wildebeest in the Serengeti or zooplankton in an Ontario lake.”

Turgeon is also studying fisheries data intended to help sustain marine and freshwater fisheries and fish populations and – she hopes – to prevent population crashes.

She’s looking at the effects of economics and the environment on fisheries, including depleted fisheries such as those on Canada’s East Coast. That kind of model might help industry and regulatory agencies find patterns to help explain changes in fish populations, she explains.

Turgeon is working with Nudds on ideas for introducing protected areas in places like the Great Lakes. That research stems from her PhD at McGill on marine protected areas, found on Canada’s Atlantic and Pacific coasts. She says these havens protect habitats and organisms but can also benefit commercial fisheries, depending on population sizes, habitat quality and types of corridors connecting protected and harvesting areas.

“We need to model the potential effects of freshwater protected areas to see if they could help fisheries,” says Turgeon.

Looking at similar questions took her to the so-called Gold Coast of Barbados and the Bellairs Research Institute, run by McGill. Working with now-retired McGill biologist Donald Kramer, Turgeon spent three field seasons – from 2005 to 2007 – studying fish on reefs only metres below the surface of the Caribbean.

Among numerous species cruising those shallow sunlit waters are damselfish. Only as big as a finger joint, these fish protect small, well-defined territories that Turgeon was able to map precisely on the reef. “They live their whole life in one square metre.”

The pint-sized creatures patrolling their small domains provided a natural experimental grid – perfect for an ecologist interested in learning more about threatened coral reef environments. No one catches damselfish – “they’re super small and taste like mud,” she says – but they make a good model system for commercial reef fishery species with home ranges like parrotfish, grouper and snapper.

“With damselfish, I can model large-scale population dynamics on a small scale, which is almost impossible with commercial reef species,” says Turgeon.

She and other institute researchers dived twice a day for hours at a time. “We developed gills almost.”

On weekends the crew often left behind the leeward ocean and drove across the island to surf and fish for lobster on the east and south coasts.

Having earned her scuba diving certificate before her doctorate, she has done about 1,000 dives, including a visit to Australia’s west coast.

During recent summers, she returned to Barbados to help teach a McGill field course. She’s also helping McGill computer scientists test underwater robots intended for deeper or more dangerous dives.

Turgeon has ventured down about 130 metres, where there’s no light, no coral and few fish. Compared to swimming in the natural aquarium on the reef, she says, “It’s a scary environment, almost a ghostly environment.”

She got interested in aquatic science during an internship spent studying fish in the St. Lawrence River. Between her grad degrees, she worked for two years for Environment Canada.

Her studies are funded by a research scholarship from the Fonds de recherche du Québec – Nature et technologies and by the NSERC Canadian Capture Fisheries Research Network.

She divides her time between Guelph and Montreal, where her partner, Sebastien Rouleau, studies frogs and reptiles at the Ecomuseum zoo on the western end of the island.