Sustaining Lakes in a Changing Environment (SLICE)

and its “so-called” sentinel lakes

Ray Valley and Don Pereira 

THE “So-Called” CONTEXT

If we rely on speculation regarding why this lake is impaired rather because we don’t have long-term datasets, we occupy the invisible present

If we focus exclusively on what we can put in the lake to “clear it up” and not deal with watershed-scale impacts, we occupy the invisible place

SLICE - Revealing the Invisible Present and Place

The Sentinel Lakes

Talk Outline The Why - History, motivations, and

aims of program

The What - Program design and sentinel lake selection

The How - Data collection activities

and partnerships

The So What – Preliminary Findings

Talk Outline The Why - History, motivations, and

aims of program

The What - Program design and sentinel lake selection

The How - Data collection activities

and partnerships

The So What - Lessons learned

“Glacieresque” Transformations of the

21st Century

Shoreline Transformations

Source: Startribune

Watershed Transformations

Hydrological Transformations

Human accelerators of species spread

Climate Change

J. Jaschke

Scheffer and Carpenter 2003

Cum

ulat

ive

impa

cts

of

stre

ssor

s

System “state”

Consequences on Resilience

• Cumulative impacts of stressors

• Stressors to watersheds• Ditching, draining, channeling,

• Impervious surface

• Withdrawing & damming

• Alterations to lakes• Overharvest/Overstocking

• Removal of structure

• Disturbance from watercraft

• Time Lags

• Hysteresis – “can’t go back”• Positive feedbacks

Reality Bites!

In a lot of systems there’s no “going back.” Our expectations and

management approach for these systems should be

different for systems largely “intact”

Enter SLICE – informing expectations and appropriate mgt responses

We ask:1. In highly altered systems, how can we

realistically improve water quality and provide a self-sustaining recreational fishery?

2. In high integrity systems, what watershed and in-lake factors are contributing to their resilience, and how can we keep those resilience mechanisms intact?

3. Early Detection and Rapid Response indicators What indicators tell us “all is not well” and indicate whether our responses are making a difference?

Program aims to: Timely detect change to

habitat conditions and species population communities

Understand and project what is/will come into our lakes (watershed modeling)

Understand and project the ultimate fate of external and internal loads (limnological modeling)

Facilitate structured decision-making and adaptive management

Sustaining Lakes in a Changing Environment (SLICE)

Talk Outline The Why - History, motivations, and

aims of program

The What - Program design and sentinel lake selection

The How - Data collection activities

and partnerships

The So What - Lessons learned

Phase 1 (Pilot; 2008-2011): Pilot phase Establish

network of sentinel lakes

Partnership and infrastructure building

Independent research projects to assess specific questions

Indicator ID

Eating the elephant one bite at a time!

chrisnierhaus.com

Economists use a large number of indicators to gage the “health” of the economy

Lakes should be no different

Maximum depth of vegetation growth Growing Degree Days

Temperature at Dissolved Oxygen = 3 mg/L Density of Daphnia > 1 mm long

Fish Index of Biotic Integrity Proportion of lake volume conducive to growth of coolwater fish

Proportion of warm water species guilds in net catches Total Phosphorus

Frequency of occurrence of curly-leaf pondweed Catch per effort of common carp

Bluegill age at maturation Catch per effort of large largemouth bass

Proportion of microcystis algae to chl a Proportion of lake volume that is hypoxic

Aquatic Plant Index of Biotic Integrity Secchi water clarity

Phase 1 (Pilot; 2008-2011): Pilot phase Establish

network of sentinel lakes

Partnership and infrastructure building

Independent research projects to assess specific questions

Indicator ID

Phase 2 (2012-2016) Using lessons

learned in Pilot to guide operational program

Eating the elephant one bite at a time!

chrisnierhaus.com

Adaptive Management Process

Assess problem

Evaluate

Adjust

Implement

Design

Monitor

Phase 1: Oct – Jan 2006/2007

May-Jun 2007

Apr. 2008

2008-2011

Phase 2

Phase 1 Op plan

Experimental Design

Three R’s of Statistical Study Design• Realism

• Randomization• Representation

Population Sample

Inference

Objective of SLICE:

Annual inference of status and trends in lake indicators at the

Landscape Scale

SLICE Design = “Split-Panel”

Panel 1: Sentinel Lakes (2008 - )

= The network of sentinel lakes

Year

1

3

2

5

4

7

6

8

• Stratified sampling design

• Figurative Approach: “6-in wide, 1 mile deep”

• Monitoring system-wide changes at a fine temporal resolution in a small number of systems spread across the state

• Tracking coherent dynamics (e.g., are things behaving similarly across large scales?)

• Cause-effect inference

• Forecast modeling w/ cont. verification

Panel 2: “Random” surveys (2013 - )

Year

1

3

2

5

4

7

6

8

• Stratified – Random (Strata = Landtype)

• Approach: “1 Mile-wide 6” deep”

• Focus is on maximizing lakes sampled, minimal time spent at each one.

• Combination with Sentinel panel is powerful for robust inference of status across time and space

• Will focus on utilizing datasets from other ongoing monitoring programs

= Group of Lakes

Sentinel Lake Selection

1. Landtype x 4

Sentinel Lake Selection intent: evaluate status and trends over a gradient of lake conditions

2. Mixing x 2

3. P-Concentration x 3

Other considerations with final candidate pool

PCA “reference” lake Other historical datasets

• Paleolimnology• Rich lake survey history

Unique partnership opportunities• Active local water monitoring

programs

Sentinel Lake Characteristics (ranges)Min Max

Watershed Size (acres) 278 595,864Lake Size (acres) 91 5,047Lake Max Depth (ft) 11 208Avg Total P (ppb) 6 (O) 278 (HE)Avg Secchi (ft) 2 19GS Length 2009 (d > 5C) 185 236Avg. Epi Summer Temp (C) 18.4 22.1Alkalinity (mg/L CaCO3) 13 317# on 303d impairment list 6

Talk Outline The Why - History, motivations, and

aims of program

The What - Program design and sentinel lake selection

The How - Data collection activities

and partnerships

The So What - Lessons learned

What we’re measuring

Fish

Aquatic Plants

Research Questions & Partnerships Merging of aspects of DNR, PCA, and SNF

lake survey programs (operational funds) Super-sentinel research

• “What if” modeling of landscape and climate change on water quality and oxythermal habitat in three lakes (Carlos, Elk, Trout)

• ENTF funded w/ USGS match• USGS (PI Dr. Richard Kiesling)

Reconstruction of water quality and correlations to past climate cycles and land use changes• Cold water sentinel lakes• SCWRS (PI Dr. Mark Edlund)• ENTF funded

Research Questions & Partnerships Cisco population assessment methods and

biology• Evaluation of hydroacoustic sampling tools• UMD (PI Dr. Tom Hrabik)• ENTF funded

Indicator research project• signal:noise ratio• best survey methods for robust snapshot of

status• Aspects of entire lake ecosystem measured• Game and Fish Fund, Fed-Aid

reimbursement

“If you build it, they will come”

A platform for interdisciplinary study of lakes

Independent “off-shoot” projects focused on:• Cold-water fish and habitat• Historical reconstructions of water quality and

zooplankton• Zooplankton patterns• Groundwater-surface water interactions

“Free” Analysis off of our “Free” data Projects, investigators, lakes involved, and

contact info is being tracked on SLICE web page

Serendipity: Curly-leaf pondweed case study • Been here for 100 years

• Widespread throughout S and central MN and moving north.

• Grows under ice and needs some winter light

• Can grow abundantly and form mats early in spring in nutrient-rich lakes

• In warm nutrient-rich lakes, dies off by early summer and algae blooms typically follow.

• Expected to benefit from shorter winters and earlier springs

Growing Degree Days Departure from Normal

Expectation: 2010 should have been a gangbuster CLP year

WRONG!

-30

-20

-10

0

10

20

30

40

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Year

St. Olaf Pearl St. James Portage Peltier

Dec.

+ Ja

n. S

now

fall (

in) d

epar

ture

from

nor

mal

(1

971

-200

0)

In Conclusion… SLICE is unveiling the invisible present and place

Preparing for rather than reacting to change

Situational awareness – detecting change quickly and the scale its occurring

Sentinel Lakes as ongoing sites of learning and a platform for interdisciplinary explorations

Funding and Partners