Mersey Tobeatic Research Institute (MTRI) : Institut de recherche du Mersey Tobeatic


MTRI is a non-profit co-operative with a mandate to promote sustainable use of natural resources and biodiversity conservation in the Southwest Nova Biosphere Reserve and beyond through research, education, and the operation of a field station.

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Backyard Biodiversity

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Terrestrial Liming Project

Trout and salmon are threatened by numerous regional and local factors including acid precipitation, overfishing, climate change, habitat alteration and fragmentation, and the introduction of invasive alien organisms. These fish are an important part of the local biodiversity and cultural history because they were a historical food source for predators and aboriginal people, early settlers, and a coveted catch for sportfishers. Although generally pristine and free of point source pollution, surface waters in the acidic Medway, LaHave and Gold River watersheds have a low buffering capacity and have collected inputs of acid precipitation from the long-range transport of air pollution. Acid emission reductions have not, on their own, resulted in sufficient improvements to water quality and Atlantic Salmon populations continue to decline. Although not tested in Nova Scotia to date, catchment or terrestrial liming merits consideration to mitigate the effects of acid precipitation and to improve salmonid habitat.


Lime, as shown above, is pulverized limestone which is primarily made up of calcium carbonate. It is used as a treatment in water or on soils to create alkaline conditions, or less acidic conditions, which are favoured by trout and salmon species.


Project objectives

  • To gather information relating to salmonid habitat in the Medway, LaHave and Gold River watersheds.

  • To map salmonid habitat information using ArcGIS software.

  • To identify potential terrestrial liming sites by overlaying soil, forest, property ownership data, and current salmon populations. 



  • Published and mapped data were gathered from the Geological Survey of Canada, the Nova Scotia Department of Natural Resources and the Nova Scotia Geomatics.

  • Published and unpublished electrofishing data were collected from the Department of Fisheries and Oceans, Bluenose Coastal Action Foundation and Nova Scotia Power Incorporated

  • Representatives from the following associations were interviewed to determine where salmon populations persist: LaHave Salmon Association, Medway Salmon Association, Queens County Fish and Game Association, Nova Scotia Salmon Association and the Atlantic Salmon Federation.

  • All of the data were mapped using ArcGIS software.

  • The information was interpreted with mapping technology and used to select potential liming areas in each watershed which deserve future study. 



  • Data relating to salmonid habitat in the Medway, LaHave and Gold watersheds were mapped, organized and stored in a database.

  • Eleven sites were selected as the best known areas for potential liming areas.

  • A report with all results and recommendations was presented to Environment Canada in preparation for the next phase of the research project. 


Years of data

  • 2008 - 2009



  • Environment Canada

  • Nova Forest Alliance

  • Atlantic Salmon Federation

  • Bluenose Coastal Action Foundation

  • Department of Fisheries and Oceans

  • Nova Scotia Power Inc.

  • Queen County Fish and Game Association

  • LaHave River Salmon Association

  • Nova Scotia Department of Fisheries and Aquaculture

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