Mercury Levels in Food Fish Species in Lakes Used by Dehcho Community Members with a Focus on Choice and Risk Perception of Eating Traditional Country Food

Project Leader: George Low, Dehcho First Nations, Hay River
Tel: (867) 876-0441, ;

Project Team Members and their Affiliations: Dahti Tsetso and Mike Low, Dehcho First Nations;Heidi Swanson, University of Waterloo; Marlene Evans, Environment Canada; Bruce Townsend, BEAT Environmental Inc

Northern Regions Included in the Study: NWT

Project Duration: 2011-2015

2014-15 Synopsis


Mercury levels in fish in some Dehcho lakes have been found to be high and increasing in some cases. The Dehcho Aboriginal Aquatic Resources and Ocean Management (AAROM) program has been collaborating with Dr. Marlene Evans of Environment Canada on her temporal study of mercury levels of fish in Dehcho Region lakes. AAROM has contracted community First Nations in the region to collect fish for sampling from fishing lakes in Dehcho territory. Environment Canada analyses the samples for mercury levels and reports results back to the Dehcho AAROM and to NCP.

Dr. Heidi Swanson of the University of Waterloo is collaborating with Dehcho AAROM in a study titled; “Understanding and predicting fish mercury levels in the Dehcho Region using models of bio-magnification and bio-accumulation.” Most of our study funding is provided by NWT CIMP, the Dehcho AAROM and in-kind from the University of Waterloo however NCP provides funding for the analysis of mercury and stable isotopes. We have completed the second year of a three year study with the sampling of Trout, Ekali, and Sanguez lakes in 2013 and Tathlina, Gargan and McGill in 2014. Kakisa, Mustard and Big Island lakes will round out the study in 2015. (Study detail is on the Polar Data Catalogue # 11918).

NCP has shared funding of our annual “A Return to Country Foods” workshop. The 2014 workshop was successful with Grand Chief Herb Norwegian speaking of the benefit of traditional and scientific knowledge complimenting each other. Forty eight First Nation and Metis leaders, environmental managers, elders and harvesters discussed various studies as presented by eight researchers and government managers. All went away with a better understanding of each other’s perspectives on the mercury issues and the importance of including fish in a healthy diet. Chief Stanley Sanguez of Jean Marie River recommended that researchers design a fish-down study of Sanguez Lake to see if the population of large, old predator fish could be removed and a more normal population established. Results of this AAROM funded pilot study may be applicable to other lakes with similar population imbalances.  

Key messages:

·         Mercury levels in some predatory fish in some lakes in the Dehcho Region have been found to be high and in some cases increasing.

·         Fish from Dehcho lakes are being checked for mercury levels and low risk lakes and species are being identified for community fisheries.

·         Heidi Swanson, a researcher from the University of Waterloo is studying the understanding and predicting of mercury levels in fish using models of bio-magnification and bio-accumulation.

·         The 3rd annual Return to Country Food workshop brought together First Nation and Metis leaders, environmental managers, elders and harvesters with researchers and government managers resulting in a greater understanding of each other’s mercury concerns and issues.

·         A mitigation strategy for lakes with fish populations that have high mercury levels was discussed and resulted in a recommendation for Dehcho AAROM to lead a fish-down study of a representative lake with involvement of the community of Jean Marie River.

Synopsis (2013-2014):


The annual Country Food Workshop series is an ideal forum to increase communication between government and university researchers and the Dehcho leadership. The workshop provides an excellent opportunity for Dehcho leaders, environmental coordinators, community members, and university and government researchers to meet and share ideas and opinions. It not only provides researchers with a forum to explain their studies and present their findings but it also gives the Dehcho community delegates the chance to have their Traditional Knowledge and experience built into the process of understanding the aquatic environment.

The Dehcho Aboriginal Aquatic Resource and Oceans Management (AAROM) is working towards finding fishing lakes with acceptable levels of mercury in fish for each of the communities. This strategy will include Great Slave Lake and Mackenzie River fish that usually have low mercury levels.

The University of Waterloo mercury bioaccumulation study was designed by Dr. Heidi Swanson to answer several questions: Why do some lakes have high mercury and others low mercury levels? Why are levels in some lakes increasing while others are decreasing? Are there ways to mitigate mercury levels in fish populations? It’s a complex issue which includes climate change effects as well as other factors such as harvest rates.

The Dehcho AAROM Youth program is now focused on “Clean Water, Healthy Food and Good Choices”. We recognize the importance cultural and spiritual wellbeing in our youth program, and youth camps usually include Elder and harvester Traditional Knowledge as well as bush skills and safe practices.

Key Messages

  • AAROM, in partnership with researchers and community monitors, are building a data set that will serve to advise our membership on low risk fishing species and lakes in the Dehcho, but will also warn them of high risk fish through GNWT-Health and Social Services consumption advisories.

  • Fish species from eleven fishing lakes were checked for mercury levels during the study (2010 – 2013). In some cases, lake whitefish were checked even though this species is generally low in mercury. The purpose of this approach was to reassure our members in the Dehcho that whitefish and other non-predatory fish are a good food choice in any lake.

  • Lake whitefish were found to be low in mercury in all lakes tested.

  • Northern pike were found to be below 0.5 parts per million of mercury in Big Island Lake, Mustard Lake and Willow Lake, however they were over 0.5 parts per million in many of the fishing lakes.

  • Walleye were found to be below 0.5 parts per million of mercury in Willow Lake.

  • Lake trout were below the 0.5 mark in Big Island Lake, Trout Lake, Fish Lake and Willow Lake. However these species were found to be high in mercury in many Dehcho fishing lakes.

Project Summary (2013-2014)

The Dehcho First Nations (DFN), in collaboration with Environment Canada, has been updating the data on mercury levels in fish from lakes in the Dehcho region. Mercury levels in predatory fish in some lakes may be increasing due to climate change and other factors. In some cases the new levels of mercury in fish have increased and even doubled. New health advisories have been issued for some fish types in certain lakes by the GNWT - Health and Social Services. During the 2013-14 fiscal year, the Dehcho First Nations will continue to provide logistical assistance with the collection of fish for contaminant analysis in order to identify lakes that have a variety of fish species with safe levels of mercury for consumption; support researchers who are studying mercury contamination and pathways in Dehcho lakes; and provide a forum for Northern Contaminants Program researchers and others to communicate project results to the Dehcho communities through a variety of workshops and other communication initiatives. The project team’s research emphasis is changing from the collection and analysis of fish for mercury, to including the study of the apparent shift in diet from fish and other traditional food towards a market-based diet. People in some communities are consuming less fish and other country food. Part of the reason seems to be a perception that water and fish are no longer safe because of the presence of mercury and other contaminants. These perceptions need to be examined and addressed at the community level in order to encourage people to return to a healthy traditional diet.

Synopsis (2012-2013):

The Dehcho AAROM program has been involved, for the past several years, in the collection of fish samples for mercury analysis from inland lakes fished by our member communities. In 2012-13, we collected fish samples from Trout, Gargan, Tathlina and Little Doctor lakes to update mercury level data. We also sampled a promising site, Mustard Lake in the Horn Plateau, to continue our search for alternate lakes where the fish are low in mercury. We have partnered with Environment Canada who analyse the samples and with GNWT, Healthand Social Services who issue consumption guidelines as necessary. In 2012-13, a total of 141 fish from 5 lakes were sent to DOE.

We have learned from community leaders and harvesters during our communication processes that an unfortunate side effect of our mercury studies is that some of our members are no longer eating locally caught fish regardless of species, size or lake status. As a result we have changed our focus to communicating positive messages and finding safe sources of fish for each of our communities. “The Return to Country Food” workshop brought together leaders, resource managers and harvesters to learn more about contaminants and also about the health benefits of including fish and other country food in the diet. We are working with Health Canada on a country food diet survey and with GNWT, Health and Social Services to promote healthy eating. We have developed a mercury learning module for our youth programs and have begun to deliver healthy eating messages as a part of our youth camp curriculum.

Key Messages

  • There is a need for better communication on water quality and contaminants such as mercury in the Dehcho region.
  • The health benefits of eating fish far outweigh the risks from mercury contamination in the Dehcho. Eat smaller (younger) fish and non-predators such as whitefish and suckers. Follow GNWT consumption guidelines if you eat predatory fish on a regular basis.
  • All species of fish from Great Slave Lake, Willow Lake and Big Island Lake are low in mercury; Non-predatory fish such as Lake Whitefish, suckers and grayling are generally low in mercury in all lakes or rivers in the Dehcho

Synopsis (2011-2012):

The Dehcho First Nations is requesting funding in order to update mercury levels data in fish from lakes utilized by Dene and Métis community members. The recent release of mercury data by Environment Canada and the new health advisories from Health Canada have caused increased concerns in our communities. There are lakes and species of fish which are safe to harvest and contain acceptable levels of mercury. We want to be able to reassure people in cases where risks are low and warn people in cases where health advisories have been released. There may be a need to reevaluate health risks due to the possible increase in mercury due to climate change or other unknown causes. This project will continue next fiscal year and into the future until a complete update of "fishing lakes" have been assessed. Next fiscal year our application for funding will include work with GNWT Health to build a comprehensive communications plan for the Dehcho. The work this year will concentrate on collecting samples from five communities which seem to be most affected; Liidlii Kue (LKFN), Fort Simpson), Jean Marie River, (JMRFN) Ka'a'gee Tu (KTFN) (Kakisa), Fort Providence (FPRMB) and Sambaa K'e (Trout Lake). Twenty samples from each species of fish will be collected from each of seven lakes used by the communities. Marlene Evans of Environment Canada is partnering in this study and will arrange the processing, analysis and will interpret results. Data collected will be useful in her temporal
studies as well, including her investigation of special variations in mercury concentrations and time trends.

Key Messages

  • The study to update mercury levels in fish in lakes used by Dehcho Communities was continued in 2011-12.
  • Training of local people in field research techniques increased capacity through the Dehcho First Nations initiative to have trained monitors in each of the Dehcho communities.
  • Involvement of the community leadership and administration in this study will increase the capacity for collaborative management of aquatic resources in the Dehcho.
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