Reducing Risks to the Reducing Risks to the AnishinaabeAnishinaabe from from MethylmercuryMethylmercury

GLIFWC’s Mercury ProgramGLIFWC’s Mercury Program

Matt HudsonMatt HudsonEnvironmental BiologistEnvironmental Biologist

Great Lakes Indian Fish and Wildlife Commission (GLIFWC)Great Lakes Indian Fish and Wildlife Commission (GLIFWC)

GLIFWC MissionGLIFWC Mission Assist member bands in the Assist member bands in the

implementation of off-reservation harvest implementation of off-reservation harvest seasons seasons

Protect treaty rights and natural resources Protect treaty rights and natural resources GLIFWC providesGLIFWC provides

natural resource management expertisenatural resource management expertise conservation enforcementconservation enforcement legal and policy analysislegal and policy analysis public information servicespublic information services

Tribal Walleye HarvestingTribal Walleye Harvesting

SpearingSpearingNettingNetting

Inland Lake Walleye Harvest – Inland Lake Walleye Harvest – 1837 and 1842 Ceded Territory1837 and 1842 Ceded Territory

Mercury and fish Mercury and fish consumptionconsumption

Major route for human exposure to Major route for human exposure to mercurymercury

Walleye top predator fish that often Walleye top predator fish that often contain elevated levels of mercurycontain elevated levels of mercury

Algae Zooplankton Fish People

Fish is a healthy and culturally Fish is a healthy and culturally important food sourceimportant food source

Other available consumption Other available consumption advisories don’t typically consider advisories don’t typically consider cultural aspects of fish consumptioncultural aspects of fish consumption

Challenge is Challenge is maximizingmaximizing health and health and cultural cultural benefitsbenefits while while minimizing minimizing risksrisks

Mercury and fish Mercury and fish consumptionconsumption

To develop, implement, evaluate, To develop, implement, evaluate, and document a comprehensive, and document a comprehensive, systematic, and culturally-sensitive systematic, and culturally-sensitive intervention program to reduce risks intervention program to reduce risks associated with subsistence based associated with subsistence based consumption of methylmercury consumption of methylmercury contaminated fish.contaminated fish.

GLIFWC’s Mercury Program GLIFWC’s Mercury Program GoalGoal

GLIFWC’s Mercury ProgramGLIFWC’s Mercury Program Main FocusMain Focus

Mercury data collection (since 1989)Mercury data collection (since 1989) Outreach through consumption advisory maps (since 1996)Outreach through consumption advisory maps (since 1996)

In Addition – Collect information to inform and improve consumption advisory processIn Addition – Collect information to inform and improve consumption advisory process Fish consumption studyFish consumption study Science-based advisory methodologyScience-based advisory methodology Targeted interventionTargeted intervention Evaluate interventionEvaluate intervention Trend and Risk AnalysesTrend and Risk Analyses

Year

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

Num

ber

of W

alle

ye S

ampl

es

0

100

200

300

400

500

600

Walleye Samples Collected by GLIFWC Walleye Samples Collected by GLIFWC for Mercury Testing by Year (Inland for Mercury Testing by Year (Inland

Lakes)Lakes)

Walleye Advisory MapsWalleye Advisory Maps

Walleye Consumption by GLIFWC-Walleye Consumption by GLIFWC-Member TribesMember Tribes

Intervention ProgramIntervention Program

FocusFocus Fish Harvesters Fish Harvesters WI Women of Childbearing Age and ChildrenWI Women of Childbearing Age and Children

ApproachApproach Tribal Leaders Tribal Leaders GLIFWC Wardens GLIFWC Wardens EldersElders Broad Dissemination of MapsBroad Dissemination of Maps

Evaluate effectivenessEvaluate effectiveness Pre-intervention surveysPre-intervention surveys Post-intervention surveysPost-intervention surveys

How Effective Was Our How Effective Was Our Intervention?Intervention?

Awareness of maps increased in all surveyed groups

Concern about mercury in fish increased Preference for smaller walleye increased Harvesters were labeling fillet bags with

lake name Few using maps to choose lakes for harvest Tribal lifeways not affected by advisory

program

Other Ways We are Using Other Ways We are Using Mercury Program DataMercury Program Data

Mercury Concentrations in Walleye in Northern WI

Declining Over Time

0.0

0.1

0.2

0.3

0.4

0.5

0.6

1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005

Year

Mer

cury

(μg/

g) .

Male Skin-Off Fillets

Male Skin-On Fillets

Female Skin-Off FilletsFemale Skin-On Fillets

Fine dotted lines give bounds that have a 95% probability of containing the regional trend lines

Estimating Mercury Exposure to Tribal Fish Harvesters

Probabalistic Risk Assessment – Lifeline Software

Harvest Data Mercury Data Consumption Data

Mercury Exposure Risk Analysis

Acknowledgements

Adam DeWeese, Former Environmental Biologist, GLIFWC

Neil Kmiecik, Biological Services Director, GLIWFC

Jeffery Foran, Ph.D., EHSI LLC ATSDR and EPA for funding