# ~ 

# -- **~ ~)**  

# (~ **~** 

# ~ **~** 

# ~

**~** We have several reasons for betng concerned about mercury contamination

of local ftsh In a 

### maJOr survey of fish mercury levels conducted
by the EPA, the walleye

tn Btg Horn Reservo1r
on the ReservatiOn had some of the htghest levels


## 1n the country The coal burmng power plant 

### tn nearby Colstnp

LS the maJor source of atmosphenc mercury pollut1on

m the state of Montana, and addtt1onal power plants are located
tn B!lhngs and Hardin MT Atmosphenc depos1t10n
of mercury
to land and water surfaces leads to converston

of elemental mercury tnto methylmercury (MeHg)

1n aquattc ecosystems Methylmercury

1s b1omagn1fied

up the aquat1c food cham by a factor of 10 m1!11on
1n top predators Humans, b1rds and mammals eating contam1nated fish have the highest levels of exposure

In the US 8% of women of chlld- beanng age are cons1dered

to be at nsk due to h1gh blood MeHg levels 410,000 ch1ldren per year are exposed
to levels 1n womb associated 'N'lth neurologtcal tmpatrment On the Crow Reservat1on somP of the natives regularly eat local fish The two maJor nvers are the L1ttle Bighorn and B1ghorn the smaller tnbutanes are Pryor Creek Lodge Grass Creek and Soap Creek Ftsh are also consumed from Willow Creek Reservo1r Our proJeCt,

a collaborat1on among L1ttle B1g Horn College the Crow Tnbe the lnd1an Health Serv1ce Hospttal the Crow Water

& Wastewater Authonty Montana State Umvers1ty Bozeman and the US F1sh & W1ldhfe Serv1ce, collected the first ava1lable data on fish mercury levels from most of these water bod1es 

# -;.---' 

# -----~~. **;:-r<-~~.,** 

# ' 

# \-:- ·1 ... ._



# \ Figure

1 F1gure

2 F1gure

3 Crow Reservat1on L1tne Bigham Watershed Pryor Watershed ..

l 

# ' -."'"': ' 

# ~.:}~· 

# Mercury levels detected

in fish from rivers of the Crow Reservation, Montana



# M =:rescentia Cummins

1 , 

# Mari Eggers

2 , 

# Steve Hamner

2 , 

# Anne Camper

2 

# and Tim Ford

3 1 

# Little Big Horn College,

2 

# Montana State University, and

3 

# University
of New England 

# MONTANA

51:\,rll 1}:-llVERSliY Summer 2008 Electrorishmg Crew (L toR) M•cah Wh•le Clay Crescen11a Cumm1ns Jul1an Goes Ahead Antone Lopez Glenn Boltz Robbin Wagner Audrey Plenty Hoops and Jarv•s Gus! (M1ssmg Justin Hugs Sara Ptaggemeyer Man Eggers and Ada Iron)

Deep Nater under !he bridge on the L1ttle B·g Horn R•ver was a challenge L toR Juhan Goes Ahead MICah While Clay Crescent1a Cumm1ns Glenn Boltz Jarv1sGus\
Consumpt1on gU1del1nes state that people at h1gher nsk should not consume more than one servtng per month of any fish wrth methylmercury levels 1n the range of 0 170-

0 650 ppm In th1s h1gher nsk group are women of ch1ldbeanng age nurs1ng mothers, and children SIX and under AU other people should not eat more than one **serv~ng** per week of such fish (dphhs mt gov/fish2005) Ed1ble fish 1n our survey wh1ch are contaminated

at th1s level on elude (a) brown trout 12" and larger from W1llow Creek Reservoir, and 16" and larger from the L1tlle B1g Horn R1ver (b) ra1nbow trout 12 and larger from Willow Creek Reservoir and (c) small mouth bass and larger from L1ttle B1g Horn R1ver Some of the channel catfish 12' and larger from the Little Bog Hom R1ver also were s•mtlar1y contam1nated Smaller trout catfish and small mouth bass were less contam1nated and therefore

a safer cho1ce for consumpt1on The larger brown and ratnbow trout 10 Willow Creek Reservo1r are of part•cular concern s1nce the Reservo1r

15 a popular fish1ng area Th1s ReservOir

1s located

tn the foothills
of the 81g Horn Mountams

rt seems hkely that the maJor source of contam1nat1on 1S aenal depos1t1on Hav1ng coal bum•ng power plants dose to the Crow Reservation has caused concern Not very many people eat f1sh on the Reservation, but the ones that do eat fish eat a lot of f1sh The f1sh 1n W1llow Creek Reservo1r had h1gher concentrat1ons

of methylmercury The fish caught upnver
1n Pryor Creek had the lowest concentrations
We found levels
tn some fish that would warrant an adv1sory
to hm1t consumpt1on Pubhc education w1ll be an tmportant aspect of th1s work, and ts planned for th•s spnng pnor to the beg1nn1ng
of the fishtng season As we only tested fish fillets, further testtng Will be needed

1f people are also eat1ng fish sk1n or other parts of the fish A survey

IS be•ng conducted

to determ1ne how much fish people are eat1ng and of wh1ch spec1es Montana Department

of Public Health and Human Servtces 2005 Montana Sport F1sh Consumpt1on Gu1dehnes http //www dphhs mt gov/fish2005 http 

### lmns stow 'Tit aov http 

### //www 

### stopthe~oalptant
org l•ttle B1g Horn College PrOject Coord.nator Cummms and mtern Lopez leachwaterqualltymonllonngtolocalschool

children The members
of the Crow Envtronmental Health Steenng Comm1ttee who help gu1de th1s work are Urban Bear Don



### t Walk Ada Bends John Doyle Will,am Dnftwood, Roberta f,tch Larry K1ndness Myra Lerthand Athal1a Rose Mom son Theo Round Face Suzette Nan to-Spang and Sara Young We thank Robbm Wagner and h1s colleagues from the US F1sh and W1ldhfe Serv1ce The research descnbed

1n th•s presentatiOn was supported
by the Nat,onallnstotute

for Health Grant Number P20 RR·16455--04 from the INBRE Program
of the Nat1onal Center For Research Resources NIH Grant Number

2 R25 GM056806-0g Grant Number P20MD002317 from the Nat1onal Center on Mononty Health and Health D1spant1es NIH EPA STAR Research Assostance Agreement #FP91674401
and Research Infrastructure

for M1nonty lnst•tut1ons, NIH Ne1ther NIH nor EPA has off1C1ally endorsed th1s pubhcat10n and the v1ews expressed here1n may not reflect the v1ews of NIH or the EPA