Final Report: Multi-level Indicators of Ecosystem Integrity in Alpine Lakes of the Sierra Nevada

EPA Grant Number: R827643
Title: Multi-level Indicators of Ecosystem Integrity in Alpine Lakes of the Sierra Nevada
Investigators: Oris, James T. , Bailer, A. John , Guttman, Sheldon I. , Miller, Glenn C. , Reuter, John E.
Institution: Miami University , University of California - Davis , University of Nevada - Reno
EPA Project Officer: Hahn, Intaek
Project Period: September 13, 1999 through September 12, 2002 (Extended to September 12, 2003)
Project Amount: $894,627
RFA: Ecological Indicators (1999) RFA Text |  Recipients Lists
Research Category: Ecosystems , Ecological Indicators/Assessment/Restoration

Objective:

The overall objective of this research project was to develop protocols for environmental assessments of alpine lakes in the Sierra Nevada with a range of human impacts. These assessments were conducted over the range of levels of biological organization (molecular to ecosystem) utilizing currently available assessment techniques and with the addition of two new ecological indicators. The use of population genetics analysis as a response indicator and the use of molecular biomarkers of exposure to contaminants as a diagnostic indicator were proposed for incorporation into monitoring and assessment programs for surface waters. These indicators were used to provide information concerning the status of population diversity and stability and concerning the exposure to nonpersistent, nonbioaccumulative contaminants.

The overall objective was met by addressing the following four specific objectives:

  • Conduct standard environmental assessments of a select group of alpine lakes with a defined range of human impacts. There was a total of 16 assessment sites. Those selected for assessment initially included four minimally impacted areas (Castle Lake, Eagle Lake, Marlette Lake, and Upper Angora Lake), seven areas with a range of moderate impacts (Fallen Leaf Lake, Gold Lake, Lake Tahoe at Sand Harbor, Prosser Creek Reservoir, Spaulding Reservoir, Stampede Reservoir, and Upper Twin Lake), and five highly impacted areas (Jackson Meadows Reservoir, Donner Lake, Lake Tahoe at Tahoe City, Lake Tahoe at Tahoe Keys, and Topaz Lake).
  • Conduct population genetic assessments in fish and invertebrates in these same assessment areas. Allozyme electrophoretic analysis and randomly-amplified polymorphic DNA (RAPD) analyses originally were to be conducted on two organisms common to the lakes of the region (fish: Lahontan redside; invertebrate: Signal crayfish).
  • Conduct contaminant exposure assessments in fish using molecular biomarkers of exposure in the gills and livers of fish. Five markers indicative of different types of exposure and that can account for interactions among complex mixtures of contaminants were measured over time in the assessment areas using caged rainbow trout.
  • Apply these additional techniques to current assessment protocols. Our goal was to be able to analyze the discriminatory ability of the assessment techniques using the current protocols compared to the protocols with the two new indicators added. We hypothesized that because current protocols do not account for genetic diversity or nonpersistent contaminants, the addition of these new indicators would enhance monitoring and assessment programs for surface waters.

Summary/Accomplishments (Outputs/Outcomes):

Miami University, University of Nevada at Reno, and University of California at Davis Tahoe Research Group participated in the U.S. Environmental Protection Agency (EPA)-sponsored project, Multi-level Indicators of Ecosystem Integrity in Alpine Lakes of the Sierra Nevada, throughout the period of funding. Field work and laboratory analyses followed the guidelines set forth in the Environmental Monitoring and Assessment Program Surface Waters Field Operations Manual for Lakes (EPA/620/R-07/001). Deviations in sampling procedures and laboratory analysis occurred when the physical features of the water body or sample collections did not lend themselves to prescribed methods. Forms adapted and used for the assessments are available in PDF format. During the summer field seasons from 2000-2002, a total of 16 sites were completely surveyed, representing 14 separate lakes. Marlette Lake, sitting on the eastern crest of the Lake Tahoe basin in Nevada, and Donner Lake, in Nevada County, California, were sampled each field season. In addition, the summers of 2002 and 2003 were used to resample lakes where data were missing or analysis indicated a need for additional data.

Table 1 presents a summary of site locations and characteristics and a summary of assessment results for all lake sites. Preassessment categories were determined using information about the types of activities known to occur in the area (e.g., housing, boating) and anectdotal information gained by people who lived in the areas. Postassessment categories were determined using a combination of the physical habitat assessment, chemical and biological characteristics, observed human influences, and molecular biomarkers of contaminant exposure. Lakes were ranked from low (good) to high (bad) for each of these subassessments. Values of subassessment ranks were summed to derive the postassessment impact scale. The postassessment impact category was then determined by natural break points in the assessment scores (change in score of 20 or greater). This resulted in a reclassification of several lake sites. Eagle Lake (in Desolation Wilderness, southwest corner of Lake Tahoe Basin) was the only lake that remained in the “low impact” category. The other three preassessment “low impact” lake sites were moved into a moderate impact category. Of note was Upper Angora Lake, where the molecular biomarker scores moved it from “low” to “moderate”. Even though no contaminants were detected by analytical chemistry, biomarker scores were high. Postassessment discussions with locals provided anectdotal information that explosives may have been dumped into the lake during the mining era. Several lakes originally categorized as “moderate” were moved into the “high” category. Topaz Lake, a reservoir in the Walker River drainage, appeared to be highly impacted, and rated a “very high” impact category. In general, it appeared that most lakes were being impacted more than what we determined by remote information and from what local people would describe.

Table 1. EPA Alpine Lake Assessment Sites and Impact Categories

Lake Site

Abbreviation

Latitude (N)
Longitude (W)

Elevation
m

Maximum
Depth, m

Surface Area
m2

Pre-Assessment
Impact Category

Post-Assessment
Impact Category

Post-Assessment
Impact Score

Eagle Lake

EA

38.942139
120.12278

2,151

24

72,144

Low

Low

90

Marlette Lake

MA

39.174167
119.90417

2,391

11

1,569,863

Low

Moderate

112

Castle Lake

CA

41.226753
122.38458

1,585

37

201,744

Low

Moderate

117

Fallen Leaf Lake

FL

38.883917
120.06592

1,952

104

5,669,554

Moderate

Moderate

121

Stampede Reservoir

ST

39.47500
120.11472

1,826

21

11,733,596

Moderate

Moderate

123

Upper Angora Lake

UA

38.862361
120.06867

2,263

13

54,335

Low

Moderate

131

Spaulding Reservoir

SP

39.327889
120.64158

1,497

90

2,440,773

Moderate

Moderate

137

Gold Lake

GO

39.683417
120.64703

1,964

33

1,997,126

Moderate

Moderate

141

Sand Harbor,
Lake Tahoe

SH

39.201139
119.93186

1,900

6

498,965,579
(entire lake)

Moderate

High

174

Upper Twin Lake

TW

39.148333
119.36808

2,166

32

1,218,078

Moderate

High

180

Prosser Creek Reservoir

PC

39.379444
120.14083

1,761

33

1,241,614

Moderate

High

185

Donner Lake

DO

39.322611
120.27208

1,808

70

3,284,294

High

High

188

Tahoe Keys,
Lake Tahoe

TK

38.937806
120.00444

1,900

6

498,965,579
(entire lake)

High

High

192

Jackson Meadows Reservoir

JM

39.504083
120.55344

1,837

33

4,028,783

High

High

205

Tahoe City,
Lake Tahoe

TC

39.169028
120.13514

1,900

3.5

498,965,579
(entire lake)

High

High

206

Topaz Lake

TO

39.148389
119.88886

1,522

23

7,002,603

High

Very High

249

The main distinguishing feature of these studies was the addition of molecular biomarkers of contaminant and stressor exposure as a diagnostic metric to the assessment protocol. Rainbow trout were used in 48-hour, in situ caged experiments at each lake site and the relative expression of a suite of genes that were up- or down-regulated in response to contaminants and stressors were analyzed. There was a strong relationship between overall biomarker response and levels of human influence at the assessment sites (Figure 1). Biomarkers served to highlight unique situations (such as at Upper Angora Lake) and to help identify potential contaminants that may have been lower than analytical chemistry detection levels or nonbioaccumulative contaminants. They were useful, especially in a monitoring context and were able to detect short-term temporal changes in contaminant loads (e.g., weekend boating activity). Thus, the biomarkers were sensitive indicators of biologically relevant exposures and/or stressors. The main disadvantage of the biomarkers was the additional time and expense added to the assessments compared to standard protocols. However, the use of biomarkers appeared to add significant, relevant information to the assessments making the extra cost and time worthwhile.

Figure 1. Summary of Overall Biomarker Results in Relation to Human Influences at Lake Assessment Sites. White bars are from low, and black bars are from high levels of human impacts (as rated from assessments). Asterisks indicate significant differences between low and high for each biomarker.

Journal Articles:

No journal articles submitted with this report: View all 25 publications for this project

Supplemental Keywords:

water, sediments, ecological effects, animal, cellular, population, enzymes, stressor, genetic polymorphisms, susceptibility, chemicals, PAH, heavy metals, pesticides, toxics, ecosystem indicators, aquatic, integrated assessment, ecology, genetics, EMAP, measurement methods, EPA Region 9, exposure, biomarkers, limnology, RNA, enzymes,, RFA, Scientific Discipline, Geographic Area, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Ecology, Contaminated Sediments, Genetics, Environmental Chemistry, Ecosystem/Assessment/Indicators, Ecosystem Protection, Chemistry, Ecological Effects - Environmental Exposure & Risk, Ecological Risk Assessment, Biology, West Coast, EPA Region, Mercury, Ecological Indicators, anthropogenic stresses, EMAP, molecular genetics, Region 9, ecological exposure, sediment, contaminated sediment, metal release, biomonitoring, ecosystem indicators, aquatic ecosystems, contaminant impact, DNA, population-based, Sierra Nevada, genetic differentiation, fish

Relevant Websites:

http://zoology.muohio.edu/oris/tahoe/ Exit

Progress and Final Reports:

Original Abstract
  • 2000 Progress Report
  • 2001 Progress Report
  • 2002 Progress Report