Ph.D. candidate Mark Poos' work on endangered fish garners attention from the media and provincial government

Friday, December 4, 2009 11:00:00 AM

Mark Poos, a Ph.D. candidate in the Department of Ecology and Evolutionary Biology and the Centre for Environment's collaborative environmental studies program, has recently garnered attention from the media and the Ontario Ministry of Natural Resources for his research work on endangered species.

One of his two research projects looks at modelling approaches for endangered species, including a small-body minnow called redside dace that is found only in Ontario and is being threatened by urban development near a small stream of the Rouge River.  This past summer, the importance of his research, done in collaboration with the Toronto and Region Conservation Authority, was highlighted by a visit from Donna Cansfield, Ontario's Minister of Natural Resources, and other dignitaries.  Minister Cansfield was on site to announce a Species At Risk Stewardship Fund for the project.  According to Mr. Poos, increased development leads to an increase of sediment in nearby waterways and an increase in temperature and deforestation, which is problematic for the fish, who like clear, running water.  He says the Rouge River has the province's largest population and the decline of redside dace is a direct reflection of what is going on in the environment.  According to recent reports, 13 out of 18 redside dace populations in Ontario are thought to be in drastic decline.

His other research project, published recently in the international journal Biological Invasions1 has attracted some media attention from several Ontario newspapers as well as US papers such as the San Francisco Post Chronicle.  The project identifies a drastic invasion of round goby into many Great Lakes tributaries, including several areas of the Thames, Sydenham, Ausable and Grand Rivers, which poses many potential threats for native species of fish and mussels.  Up to 89 per cent of fish species and 17 per cent of mussel species are either known or suspected to be affected by the goby invasion.  Of particular concern is the impact on species that have a conservation designation and some globally rare species.

The Great Lakes and its tributaries are Canada's most diverse aquatic ecosystems, but are also the most fragile, notes Poos.  Several of these rivers hold species found nowhere else in Canada, including 11 endangered species and two threatened species.  Round gobies entered the St. Clair River in 1990, likely through ballast water from ocean-going ships.  Despite more than 15 years of potential invasion through natural dispersal from the Great Lakes into tributaries, the round goby threat did not manifest itself until now.

(This is an edited excerpt of two articles found at

1M. Poos, A.J. Dextrase, A.N. Schwalb and J.D. Ackerman. 2009. Secondary invasion of the round goby into high diversity Great Lakes tributaries and species at risk hotspots: potential new concerns for endangered freshwater species Biological Invasions
Available online at