Terms of Reference

Review of Mercury Bioaccumulation in the Biota of Lake Melville

Regional Science Response Process – Newfoundland and Labrador Region

February 17, 2016
St. John’s NL

Chairperson: Keith Clarke

Context

In 2009, the Joint Review Panel that carried out the environmental assessment of hydroelectric development of the lower Churchill River considered methylmercury bioaccumulation as a potential impact.  The Department of Fisheries and Oceans and other federal and provincial authorities provided advice to the Joint Review Panel on the extent of downstream bioaccumulation.  As a result of this advice, the Panel concluded that methylmercury bioaccumulation in downstream areas could be greater than predicted by the project proponent Nalcor Energy.  In response to this conclusion and related Panel recommendations, the Government of Canada decided to require Nalcor Energy to carry out additional baseline and post-project monitoring of methylmercury in fish and seals in areas downstream of the project, including in Lake Melville.   This monitoring was formally prescribed as a condition of the authorization the Department issued in 2013 under section 35(2) of the Fisheries Act to Nalcor Energy for impacts on fish habitat from the Muskrat Falls hydroelectric dam.

There has been some discussion that information presented in a recently published scientific paper (Schartup et al, 2015) fundamentally changes the understanding of methylmercury transport and bioaccumulation, and as a result, changes to the downstream methylmercury monitoring program may be required.

Objectives

To provide advice to the Fisheries Protection Program on whether information in the Schartup et al, 2015 paper significantly changes the overall predictions about the potential for bioaccumulation of mercury in fish and seals in Lake Melville as presented by the Department and recognized by the Joint Review Panel during the environmental assessment of the Lower Churchill Hydroelectric Generation Project.

To advise whether methylmercury monitoring measures prescribed by DFO downstream of the Muskrat Falls hydroelectric dam should be changed in response to information in the Schartup et al 2015 paper.

Expected Publication

• Science Response

Participation

• Fisheries and Oceans Canada (DFO) Science, and Ecosystems Management Branches
• Environment Canada
• Academia

References

Anderson, R.M. 2011. Duration and extent of elevated mercury levels in downstream fish following reservoir creation. River. Syst. Vol. 19/3 p.167-176.

DFO. 2009. Science Evaluation of the Environmental Impact Statement for the Lower Churchill Hydroelectric Generation Project to Identify Deficiencies with Respect to Fish and Fish Habitat. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2009/024.

DFO 2011. Fisheries and Oceans Canada (DFO) Submission to the Newfoundland and Labrador Department of Environment and Conservation-Canadian Environmental Assessment Agency Joint Panel Review of the Lower Churchill Hydroelectric Generation Project.

Nalcor Energy 2012. LCP (Lower Churchill Project) Aquatic Environmental Effects Monitoring Plan LCP-PT-MD-9112-EV-PL-0001-01.

Nalcor Energy 2015. Aquatic Environmental Effects Monitoring Program: 1998 to 2014 Baseline Conditions, Muskrat Falls TF13104119.1000.

Schartup, A.T., Balcom, P.H., Soerensen, A.L., Gosnell, K.J., Calder, R.S.D., Mason, R.P., and Sunderland, E.M. 2015. Freshwater discharges drive high levels of methylmercury in Arctic marine biota. Proceedings of the National Academy of Sciences of the USA (PNAS). 2015, 112: 11789-11794.