# Presentation: 239031

## Benthic invertebrate response to heavy metal contamination in the Panther Creek drainage (Idaho): A case study using McQuire’s Metal Tolerance Index (MTI)

**Benthic invertebrate response to heavy metal contamination in the Panther Creek drainage (Idaho): A case study using McQuire’s Metal Tolerance Index (MTI)**

**Gary T. Lester – EcoAnalysts, Inc., Moscow, Idaho**
**Karen Kuzis – Kuzis Consulting, Boise, Idaho**

## Purposes:

**Purposes:**

** ****- Give a brief description of the metal tolerance index (MTI)**

-  **- Give an overview of the Blackbird mine and associated water quality issues**

-  **- ****Discuss the MTI response to copper during a baseline study conducted last fall.**

## OVERVIEW OF THE MTI

**OVERVIEW OF THE MTI**

**McGuire’s Metal Tolerance Index (MTI) was   developed using benthic invertebrate communities and associated metal data (copper) in Montana’s Clark Fork River**

**Calculated as a weighted average of tolerance values assigned to each species (similar to HBI)**

**Score ranges from zero (highly intolerant) to ten (highly tolerant)**

**0-3 = no impact; 7-10 = significant impact; 3-7 = ???**

## OVERVIEW OF THE MTI (CONTINUED)

**OVERVIEW OF THE MTI (CONTINUED)**

-  **- The index has not been published in a peer-reviewed journal**

-  **- The index has been criticized for lack of peer review**

## Blackbird Mine

**Located 20 miles SW of Salmon, ID in the Salmon NF**

**Currently inactive**

**Mined from 1900 – 1982; most active from 1949 – 1967**

**Mining operations have created 10 miles of tunnels, 4.8 million tons of waste rock, 2 million tons of tailings, numerous adits and portals**

**Tailings originally dumped directly into Blackbird Creek until 1950’s, after which tailings were dumped into an impoundment**

## Blackbird Mine (continued)

**    ****In 1982 a water treatment facility brought online to treat discharge from several adits that drain into Panther Creek.**

**Several sources still contaminating surface waters in the area**

## Slide 7

**Notes:**
Ridgetop mine that affects South Fork Big Deer and Big Deer Creeks to the North and Little Deer Creek to the East.  Both creeks drain into Panther Creek.  Not pictured is the Blackbird Creek basin to the south.

## Metal Contaminants Present in Surface Waters:

**ARSENIC**

**COBALT**

**COPPER**

**MANGANESE**

**ZINC**

**NICKEL**

## NATURAL RESOURCE USES:

**    ****Panther Creek historically served as spawning and rearing for Chinook and Steelhead**

**Anadromous runs dropped sharply following development of the mine**

**In 1954 fish kills of salmon, steelhead, trout and whitefish occurred – believed related to acid releases from the mine**

**Currently, aquatic biota are either non-existent or severely damaged in Meadow, Bucktail, SF Big Deer and Big Deer Creeks**

## THE STUDY

**   ****A proposed expansion for a cobalt mine requires a pre-operation baseline inventory.**

**On August 17-18, 2001 benthic macroinvertebrates were collected from the following locations: **

## Sampling Stations:

**South Fork Big Deer Creek**

**SF-3 Above Bucktail Cr.**

**SF-2 Below Bucktail Cr.**

## <footer>

- <date/time>

## Sampling Stations:

**Big Deer Creek**

**BD-5 Above SF Deer Cr.**

**BD-4 Below SF Deer Cr.**

## Sampling Stations:

**Panther Creek (no photos available)**

## <footer>

- <date/time>

## FIELD METHODS

**   ****Benthic invertebrates collected using modified Hess, 500 micron mesh, 0.10 meters sq.**

**3-Hess composite (across a transect) in riffle habitat**

**3 riffles sampled per site (3 reps/site)**

**Total of 0.9 meters sq. sampled at each site**

## LAB METHODS

**   ****Fixed count/known area subsampling approach (500 count) using a modified Caton subsampler**

**Invertebrates identified to genus/species where possible including Chironomidae and Oligochaeta**

## RESULTS

- <date/time>

**RESULTS**

## Water Quality – Dissolved Copper

**Notes:**
Here we can see the effect of high metal concentrations in Bucktail Creek on SF-2, and we can follow its effect down to Panther Creek.

## TOTAL DENSITY

**Notes:**
Here we can see the effect of high metal concentrations in Bucktail Creek on SF-2, and we can follow its effect down to Panther Creek.

## TAXA RICHNESS AND EPT RICHNESS

**Notes:**
We found the same spatial trend in taxa richness and ept richness that we found in total density.

## % Dominance (3 taxa)

**Notes:**
Same trend with percent dominance

## THE DOMINANT CRITTERS

***Micropsectra *****sp*****.***
***Baetis bicaudatus***
***Pagastia *****sp*****.***

***Diamesa***** sp.**
***Pagastia***** sp.**
***Baetis bicaudatus***

_**SF-3**_

_**SF-2**_

## THE DOMINANT CRITTERS

***Heterlimnius *****sp*****.***
***Cinygmula *****sp*****.***
***Stempellinella *****sp*****.***

***Pagastia***** sp.**
***Orthocladius (Orthocladius)***** sp.**
***Orthocladius (Euorthocladius) *****sp*****.***

_**BD-5**_

_**BD-4**_

## THE DOMINANT CRITTERS

***Baetis tricaudatus***
***Cladotanytarsus sp.***
***Optioservus *****sp*****.***

***Baetis tricaudatus***
***Optioservus *****sp.**
***Cladotanytarsus *****sp*****.***

_**P-1**_

_**P-2**_

## Taxa eliminated or reduced:

**SENSITIVE MAYFLIES**

**CHIRONOMIDAE IN THE TRIBE TANYTARSINI**

## MTI

**Notes:**
We can see the effect of metal contaminants being reflected in the MTI scores in what should by now be a familiar trend.

## MTI vs. Dissolved Copper*

**R-squared = 0.809, n=5**

***No copper data at P2**

**MTI**

**Dissolved Cu**

**Notes:**
The MTI is highly correlated with dissolved copper concentrations.

## MTI vs. HBI

**R-squared = -0.597, n=6**

**Notes:**
Here we see that HBI responds differently than the MTI.  It actually decreases with an increase in metal contaminants.  When taken by itself, the HBI would here suggest slight improvements in water quality resulting from outflow of Bucktail Creek, when in fact metal contamination has eliminated the Chironomidae tribe Tanytarsini that are fairly tolerant of organic enrichment.

## TOLERANCES CAN DIFFER SIGNIFICANTLY FOR ORGANIC VS. METAL CONTAMINANTS!!!

**Notes:**
A given taxon may have differing tolerances to differing stressors, and we can see the need for stressor-specific tolerance values and metrics. 

## Parting Shots:

-    **In this case study the MTI was useful in tracing the impact of metals as contaminated water flowed from headwaters to Panther Creek**

**The MTI shows promise as a diagnostic tool for stressor identification (metal contamination), although a more rigorous evaluation is suggested**

**In addition to EPT, Chironomidae are useful bioindicators of metal impacts when identified at least to genus level.**

**The MTI was negatively correlated with HBI**

**Notes:**
Regarding metals, not only are many of the EPT sensitive, but so are many of the Chironomidae genera.  When we identify Chironomidae to at least genus level, we not only increase our ability to determine impact, but we also increase our ability to discriminate between causes of impairment.

## Parting Shots (continued):

-    **The next generation of bioassessment tools is focusing on impact source determination (stressor identification)**

**In order to develop these tools, we can help by having our invertebrate samples accurately identified to lowest practical level**

**In addition, good physical and chemical data collected with invertebrate samples over a range of conditions will be extremely helpful**

**Over time, enough real-world data will be collected to develop the associations necessary to assign accurate tolerance values to each taxon (e.g. Brandt, Relyea)**