Mercury levels have increased in fish in Kejimkujik National Park, Nova Scotia. So mercury contamination poses a greater threat to loon reproduction than 10 years ago in the National Park.

Environment Canada and Parks Canada first measured mercury (Hg) levels in perch from 16 lakes in the park in 1996-1997. In 2006-2007, Neil Burgess and collaborators at the University of New Brunswick collected yellow perch from these 16 lakes and analyzed fish muscle for total mercury. Over the ten-year period between sampling events, mercury levels increased an average of 29% in fish from 10 of the 16 lakes.

Mercury levels were unchanged in three lakes and decreased in three lakes. The increase was most noticeable in smaller perch and in less acidic lakes. In 2006-2007, mean Hg levels in yellow perch in 75% of the study lakes exceeded the level known to cause a 50% reduction in the maximum productivity of common loons. This was up from 56% of the lakes in 1996-1997.

Burgess and collaborators published a paper in Environmental Science and Technology:

Wyn, B., K.A. Kidd, N.M. Burgess, R.A. Curry and K.R. Munkittrick. 2010. Increasing mercury in yellow perch at a hotspot in Atlantic Canada, Kejimkujik National Park. Environmental Science and Technology 44: 9176-9181.

Contact: Neil Burgess, (709) 772-4143, Wildlife and Landscape Science Directorate