Committee Chairs Tim Cross – Fisheries Research Ray Valley – Fisheries Research

1. Designing a long-term monitoring program to support effective management of Minnesota lake resources Committee Chairs Tim Cross – Fisheries Research Ray Valley – Fisheries Research Don Pereira – Fisheries Research Manager Al Stevens – Lake Survey Program Manager Dave Staples – Biometrician

2. Mission of a long-term monitoring program To monitor the condition of Minnesota lake habitats and fish populations using key lake ecosystem indicators that are most responsive to human and environmental stressors, and evaluate whether our division’s response to changes to lake habitats and fish populations is successful at delivering the ecosystem products and services important to the DNR’s mission.

3. Goals • Assess past and present condition of selected study lakes • Monitor changes to lake indicators and project future outcomes based on simulated changes to stressor levels • Evaluate whether management actions or policy decisions are maintaining high quality habitats and fish populations in the face of human and environmental stressors.

4. Climate Change Ag Urban/residential development Human Use Drivers Contaminants (nutrients, bacteria, metals, sediment) Removal of upland and submersed physical structure Temperature regimes Precipitation and hydrology Non-native invasive species Recreation & Exploitation Stressors Effects Altered water quality Altered food webs Altered heat budget Altered habitat Altered species diversity Altered hydrology Direct Indirect Affected Indicators Hydrology and Water Quality Physical Habitat Lower trophic levels Fish Community * Effects will depend on biophysical characteristics of the lake and watershed

5. Framing our approach within a watershed-scale biophysical context • Vulnerability of lakes to stressors will depend on: • Characteristics or alterations to the watershed that affects the amount of "stuff" coming into the lake • Variability in climate patterns • Resilience mechanisms in lakes • Challenge: identify and mitigate major stressors while protecting or building-up resilience mechanisms in lakes.

6. Study design • Split-panel design • Includes 25-30 intensively monitored sentinel systems. Sentinel lakes will be stratified by Ecoregion and Schupp lake class • A larger set of lakes randomly chosen and monitored less frequently • 3-year pilot study on sentinel systems to work out protocols, evaluate partitioning of spatial and temporal variability, and power/path analysis • Will monitor a host of stressors and indicators that span from habitat on up the foodweb • Development and simulations with lake and watershed models

7. 220 Candidate Lakes Criteria for first cut • PCA reference lakes • Diatom lakes • Solid fisheries data sets • Final Cut Considerations • Water level monitoring • CLMP • Zooplankton surveys • Fish IBI surveys • Good macrophyte surveys

8. Lake 13

9. Watershed size – 2900 ha (7100 acres)

10. Watershed condition (2000) • Excellent – Almost all forest in public ownership.

11. Lake Thirteen Resilience to Nutrient Loads • Strength - High cover of Chara (75%) • Strength – Mesotrophic • Strength – Large predator population • Handicap – moderate depth (70% littoral 15 m max depth) • Zoops? Flushing rate?

12. Outlook for Lake 13 • Good • Forest land cover is secure and development is not an immediate issue • Riparian veg and macrophytes at low risk of alteration • Possible reference lake to solely evaluate effects of climate change on lake structure and function?

13. Other lakes that aren’t so lucky • What happens to flows and nutrient loads when forest cover is converted to impervious surface? Will we have GIS products available to us that will alert us to change? • Given changes in flows and nutrient loads – how resilient is the clear water state within the lake?

14. Basin of attraction 1 Restoration - uphill Unstable Dynamics Perturbation - downhill Ecosystem State – clear water Basin of attraction 2 Condition Scheffer et al. (2001) Nature

15. Upshot: Let’s prevent damage before trying to repair it • We need good watershed AND lake models • What models are already available? • What critical data are needed to feed into the models? • How can we work together to acquire critical data?