Lake Tahoe Nearshore Evaluation and Monitoring Framework Report

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1 Lake Tahoe Nearshore Evaluation and Monitoring Framework Report TRPA Governing Board October 23, 2013 By Alan Heyvaert, Ph.D Acting Senior Director Center for Watersheds and Environmental Sustainability, Desert Research Institute Directed Action: SNPLMA - Research Round 10

2 SNPLMA Funded Research (Rounds 7 through 12) $5,000,000 $4,500,000 $4,000,000 $3,500,000 $3,000,000 $2,500,000 $2,000,000 $1,500,000 $1,000,000 $500,000 $0 $4,299,649 Erosion and Stormwater Management $3,750,692 Forest and Fuels Management $3,685,515 Science Integration (w/tsc) $2,401,303 Lake Water Quality and Invasive Species $2,210,712 Air Quality $1,912,921 Ecological Communities and Wildlife Habitat $1,567,898 Stream Restoration $1,163,077 Managing for Climate Change 2

3 Contemporary Research Efforts - Nearshore Inferring littoral substrates, fish habitats, and fish dynamics of Lake Tahoe using IKONOS data; TRPA Nearshore clarity at Lake Tahoe: status and causes of reduction; NV LTLP Predicting and managing changes in nearshore quality; SNPLMA-Round 7 Monitoring past, present and future water quality using remote sensing; SNPLMA-Round 7 Niches: nearshore indicators for clarity, habitat and ecological sustainability; SNPLMA-Round 8, NV-LTLP Development of a risk model to determine the expansion and potential environmental impacts of Asian clams; SNPLMA-Round 9, NV-LTLP Warm-water non-native fishes in Lake Tahoe; NV-LTLP Potential for pathogen growth, fecal indicator growth and phosphorus release under clam removal barriers; SNPLMA-Round 10 Natural and human limitations to Asian clam distribution and recolonization-factors that impact the management and control in Lake Tahoe; SNPLMA-Round 10, NV LTLP Linking on-shore and nearshore processes: nearshore water quality monitoring buoy at Lake Tahoe phases I and II; NV LTLP The ecology of curly leaf pondweed (Potamogeton crispus) and the potential for control using bottom barriers; SNPLMA-Round 11 Testing the survival and growth of quagga mussel in Lake Tahoe; SNPLMA-Round 11 Evaluation of nearshore ecology and aesthetics (this project); SNPLMA-Round 10

4 Existing and Current Monitoring Lake Tahoe water quality investigations: algal bioassay, phytoplankton, atmospheric nutrient deposition, and periphyton, 2000 to on-going; Lahontan, UC Davis Nearshore turbidity monitoring various and intermittent efforts from 1965 to 2012; UC Davis, DRI, TRPA, NV LTLP Tributary pollutant concentration and loading monitoring; TRPA, USGS, USFS, UC Davis, NV LTLP Aquatic invasive species prevention and control measure implementation and effectiveness monitoring; Various Shorezone ordninance effectiveness monitoring of gasoline constituents, fecal coliform, e. coli, and polycyclic aromatic hydrocarbons; USGS, TRPA, Lahontan Watercraft monitoring; TRPA Deep water Lake Tahoe Water Quality Monitoring, TRPA, UC Davis Urban stormwater pollutant monitoring (nearing implementation); Lahontan, USFS, Lahontan, TRCD

5 Project Overview Nearshore Science Team (NeST) Contributors Alan Heyvaert, Desert Research Institute (DRI); John Reuter, University of California, Davis (UCD); Sudeep Chandra, University of Nevada, Reno (UNR); Rick Susfalk, (DRI); S. Geoffrey Schladow (UCD); Scott Hackley (UCD). Technical Contributors Christine Ngai (UNR), Brian Fitzgerald (DRI), Charles Morton (DRI), Annie Caires (UNR), Ken Taylor (DRI), Debbie Hunter (UCD), Brant Allen (UCD), Patty Arneson (UCD). Nearshore Agency Working Group Shane Romsos (TRPA), Dan Sussman (LRWQCB), Jason Kuchnicki (NDEP), Jacques Landy (USEPA).

6 Project Overview Background: Long-term monitoring monitoring and assessment in Lake Tahoe historically focused on mid-lake conditions Current nearshore monitoring insufficient to detect changing conditions Needed a comprehensive, integrated assessment of existing conditions Project Objectives: Review and synthesize existing research and monitoring data Document understanding of nearshore conditions Review standards and indicators for relevance to nearshore condition Develop an integrated nearshore monitoring design Major Products: Conceptual model and indicator framework Assessment of exiting standards and indicators Nearshore monitoring and evaluation framework

7 Nearshore Desired Condition Statement Lake Tahoe s nearshore environment is restored and/or maintained to reflect conditions consistent with an exceptionally clean and clear (ultraoligotrophic) lake for the purposes of conserving its biological, physical and chemical integrity, protecting human health, and providing for current and future human appreciation and use.

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9 Nearshore Definition (Monitoring) We do not recommend any changes to existing state and TRPA legal or statutory definitions of the Lake Tahoe nearshore. Rather, the following definition addresses unique aspects of the nearshore in the context of framing our monitoring design. Lake Tahoe s nearshore for purposes of monitoring and assessment is considered to extend from the low water elevation of Lake Tahoe ( feet Lake Tahoe Datum) or the shoreline at existing lake surface elevation, whichever is less, to a depth contour where the thermocline intersects the lake bed in mid-summer; but in any case, with a minimum lateral distance of 350 feet lakeward from the existing shoreline. The 31-year average August (maximum) thermocline depth in Lake Tahoe is 21 m (69 feet).

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11 Natural rim (6223 feet) 350 foot from rim 30 foot depth contour 69 foot depth contour

12 Illustration of Factors Affecting Nearshore

13 The nearshore conceptual model:

14 Important Controllable Factors that Influence Nearshore Conditions Implement TMDL Stormwater BMPs Urban Stormwater Runoff Remove/Disconnect Impervious Cover Control Shoreline Development Prevent/Control AIS Stream & Wetland Restoration Reduce Vehicle Emissions Maintain Integrity of Sewer Infrastructure M i t i g a t e s Contaminated Groundwater Excess Fertilizer Use Impervious Cover Infested Watercraft, Aquariums Domestic Animal & Human Waste G e n e r a t e s Sediment Nutrients Aquatic Invasive Species Pathogens and Toxins A f f e c t s Clarity Trophic Status (Oligotrophy) Biological Community Composition Human Health Reduce Fertilizer Use Control Measures Primary Anthropogenic Causes Pollutants and Invasive Species Indicators of Nearshore Health

15 Assessment of Existing Standards 1. Agency representatives provided a list of existing standards (TRPA, NDEP, LRWQCB). 2. NeST sorted these standards into 38 categories with internally similar characteristics (Appendix A). 3. Brief narrative descriptions were developed for each category, along with preliminary data assessment (from bibliography) and a discussion of relevance to nearshore management or monitoring (Appendix B). 4. Categories of existing standards deemed important or relevant to both nearshore management and nearshore monitoring were carried forward and aggregated into a smaller list of internally related characteristics (Table 6-1). 5. A subset of this attribute list provided the basis for design of the integrated nearshore monitoring framework.

16 Table B-1. Existing Standards Potentially Relevant to the Nearshore of Lake Tahoe.

17 Evaluation of Existing Standards 1 See Appendix B for discussion of referenced standards

18 Indicator Framework for Monitoring

19 Standards, Indicators and Metrics

20 Nearshore Monitoring Data Support for Existing Standards Evaluation or Revision

21 Periphyton (remember N&P and not fine sediment controls growth)

22 Nearshore Conditions are Spatially and Temporally Variable

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24 Nearshore Monitoring Design

25 Next Steps Public Engagement Monitoring Program Targeted Research

26 Comments & Questions