https://www.ontario.ca/data/guide-eating-ontario-fish-advisory-database

The Government Of Ontario also publishes a map guide to eating Ontario fish:

https://www.ontario.ca/environment-and-energy/eating-ontario-fish

The post Guide to Eating Ontario Fish appeared first on Reed Harris.

Reed Harris Environmental Ltd., in conjunction with the US Geological Survey, has developed a simple model of mercury inputs and outputs from terrestrial soil systems to provide a screening level assessment of the potential delays imposed by terrestrial systems on the delivery of mercury to freshwaters.

Initial results suggest long delays in the response of terrestrial mercury export following changes in mercury deposition, on the order of decades or centuries.

The post Terrestrial Mercury Modeling appeared first on Reed Harris.

To help address this problem,   a model approach was developed that was designed to predict the distribution of fish mercury levels that exist within a region, and how this distribution would change through time if mercury deposition changed or large scale regional changes occurred for factors such as acid deposition or temperature.   In a prototype study funded by the US EPA, this model was coupled with a national scale atmospheric mercury deposition model to examine the potential response of different regions to emissions controls.

The post Regional Mercury Modeling appeared first on Reed Harris.

References:

Harris and Bodaly 1998

Harris, R.C. and R.A. Bodaly (1998) Temperature, growth and dietary effects on fish mercury dynamics in two Ontario Lakes. Biogeochemistry 40: 175-187

The post Fish Bioenergetics Modeling appeared first on Reed Harris.

Fish mercury concentrations in reservoirs can increase several times above background levels, peak 5-15 years after flooding, and take 2-3 decades to recover to levels within the natural range for lakes. Some reservoirs experience greater increases and take longer to recover than others. Mr. Harris co-developed a process-based model predicting fish methylmercury concentrations in newly flooded reservoirs (See below – Harris et al., 2009). The model, funded by Manitoba Hydro, was calibrated against data from whole-ecosystem reservoir experiments at the Experimental Lakes Area (ELA) in Ontario, Canada (FLUDEX, ELARP). It predicts peak fish mercury levels and the timing of the response to flooding. The model pays special attention to flood zone characteristics because decomposition after flooding is a key driver for increases in methylmercury levels in new reservoirs.

Mr. Harris also co-developed a simple model to predict peak mercury concentrations in fish in reservoirs, based only on the flooded area, total reservoir area and mean annual flow (See below – Harris et al., 2008; Harris and Beals 2009). The model has been calibrated separately for northern pike and walleye using historical observations from reservoirs in Quebec, Manitoba, and Ontario. The approach is currently being used for proposed reservoirs in Labrador and Ontario.

References:
Harris et al., 2009

Harris, R.C., D. Hutchinson, and D. Beals. (2009) Predicting Mercury Cycling and Bioaccumulation in Reservoirs: Development and Application of the RESMERC Simulation Model. Final Report, April 2009. Prepared for Manitoba Hydro

Harris et al., 2008

Harris, R.C, D. Hutchinson and AMEC (2009) Lower Churchill Hydroelectric Generation Project
Environmental Baseline Report: Assessment of the Potential for Increased Mercury Concentrations. March 4, 2008

Harris and Beals 2009

Harris, R.C. and D. Beals. (2009) Assessing the Potential for Increased Fish Mercury Concentrations Associated with the Proposed Gitchi Animki Hydroelectric Project – Draft Final Report (2009)Prepared for Regional Power Inc., Mississauga, Ontario, August 2009

The post Reservoir mercury modeling appeared first on Reed Harris.

Fish mercury concentrations in lakes can exceed standards for commercial sale and result in consumption advisories for individuals. This is true even in remote areas, due to long-range mercury transport and deposition, and natural features that can lead to higher levels in fish. There are many factors that affect fish mercury levels in lakes, including the rate of atmospheric mercury deposition, water quality (e.g. acidity, dissolved organic carbon), hydrology, and food web structure. There is a need for tools to help understand how these factors combine to influence fish mercury levels and to predict the effects of changes such as reduced mercury deposition, acidity or climate change.

Mr. Harris is the lead developer of the Dynamic Mercury Cycling Model (See below – D-MCM, EPRI 2009), a Windows-based simulation

model for personal computers. D-MCM is a time-dependent mechanistic model that predicts the cycling and bioaccumulation of the major forms of mercury in lakes, including methylmercury, Hg(II), and elemental mercury.

D-MCM processes include inflows and outflows (surface and groundwater), adsorption/desorption, particulate settling, resuspension and burial, atmospheric deposition, air/water gaseous exchange, industrial mercury sources, in-situ transformations (e.g. methylation, demethylation, methylmercury photodegradation, Hg(II) reduction), mercury kinetics in plankton, and bioenergetics related to methylmercury fluxes in fish.

A version of D-MCM for very large waterbodies was also developed for Lake Superior. The lake is simply too big to assume conditions will be uniform throughout.

The MCM models have been applied to a wide range of lake conditions in North America, including seepage lakes in Wisconsin and Florida, drainage lakes in the Adirondacks, Ontario and Nova Scotia, and Lake Superior. D-MCM has also been used in US EPA TMDL pilot studies in Florida and Wisconsin (See below – Atkeson et al., 2003; Harris et al., 2003). The development of D-MCM has been funded by EPRI and the Wisconsin Department of Natural Resources.

References:

EPRI 2009

EPRI (2009) Dynamic Mercury Cycling Model for Windows XP/Vista – A Model for Mercury Cycling in Lakes. D-MCM Version 3.0. User’s Guide and Technical Reference. December 2009 (R. Harris lead author)

Atkeson et al., 2003

Atkeson, T.D., D.M. Axelrad, C.D. Pollman, and G.J. Keeler (2003) Integrating Atmospheric Mercury Deposition with Aquatic Cycling in the Florida Everglades: An Approach for Conducting a Total Maximum Daily Load Analysis for an Atmospherically Derived Pollutant. Integrated Summary, Final Report. Prepared by the Florida Department of Environmental Protection, University of Michigan Air Quality Laboratory, and Tetra Tech Inc., 247 pp.

Harris et al., 2003

Harris R.C., C.D. Pollman and D. Hutchinson (2003a) Wisconsin Pilot Mercury Total Maximum Daily Load (TMDL) Study: Application of the Dynamic Mercury Cycling Model (D-MCM) to Devil’s Lake, Wisconsin. Submitted to the United States Environmental Protection Agency Office of Wetlands Oceans and Watersheds. December 2003

The post Modeling mercury cycling and bioaccumulation in lakes appeared first on Reed Harris.

The model is being used to better understand sources of mercury and factors contributing to elevated mercury levels in some fish species in the Gulf of Mexico.

The post Gulf of Mexico appeared first on Reed Harris.

Climate-related factors that will be studied for potential influences on mercury include temperature, hydrology, carbon and mercury export from terrestrial systems, in-lake water quality and trophic factors and atmospheric mercury deposition. Study results will allow policy-makers to better assess the effects of climate change on mercury risks to humans and wildlife, and to target the most important interactions between climate change and mercury for further monitoring and study.

The post Climate – Mercury Interactions appeared first on Reed Harris.

Reed Harris Environmental Ltd co-developed a simple model to predict peak mercury concentrations in fish in reservoirs, based on the flooded area, total reservoir area and mean annual flow (See below – Harris et al., 2008). The regression model was calibrated for northern pike and lake whitefish using historical observations from reservoirs in Quebec and Manitoba.

References

Harris et al., 2008

Harris, R.C, D. Hutchinson and AMEC (2009) Lower Churchill Hydroelectric Generation Project. Environmental Baseline Report: Assessment of the Potential for Increased Mercury Concentrations. March 4, 2008

The post Lower Churchill River Hydroelectric Development appeared first on Reed Harris.

Mercury concentrations are elevated in some fish species in the South River, such as smallmouth bass (e.g. 1-4 ug/g), and have remained stable or have not declined as expected.  A wide range of studies have been carried out to better understand the behavior of mercury in the South River, and to help design remedial options.

Reed Harris Environmental Ltd. chaired a committee to identify innovative approaches that could complement or replace fully engineered bank stabilization along the river.

The post South River, VA – Mercury Remediation appeared first on Reed Harris.