Lake Status Indicator Selection

David F. StaplesRay Valley

SLICE Goals1. Develop relevant indicators for

measuring lake status

2. Use indicators to detect environmental changes and their effect on aquatic communities

3. Forecast changes to lake systems

4. Evaluate effectiveness of potential management or mitigation actions

Implied Needs1. Indicators of lake status

2. Framework to connect indicator measurements to lake status

3. Means to use indicators to predict near-term lake status

4. Means to connect indicators to specific problems or solutions

→ Will require a causal model connecting indicators to lake status.

→ Developing causal model will help in choosing status indicators

→ Basis for implementing adaptive management strategy

General Indicator Selection Strategy1. Systematic and transparent process to find the best set of indicators

for inference on lake status at important spatiotemporal scales Characteristics of individual indicators are important, but are secondary to

whether or not the indicator set provides best inference on lake status

2. Utilize a causal model framework for conceptual guidance on indicator selection and interpretation. Help facilitate a rigorous selection process to increase scientific validity of

inference on lake status from indicator data.

STATE

PRESSURE

RESPONSE

EutrophicationCommunity Shift

Development RegulationsRiparian Buffer Zones

Non-Permeable SurfaceFertilizer runoff

Lake Ecosystem Model

Lake

Land

Streams

SocietyLake Flora

Lake Fauna

Available Nutrients

AgricultureNutrient/Sediment Load

Fish Community State

Water Quality

Plants Algae

Decomposers

Hydrology

Drainage Patterns

Nutrient Levels

Zooplankton

Non-PermeableSurfaces

Development Activity

Economic Benefits

Food

Recreation

Urban Development

Climate Change

Lake

Land

Streams

SocietyLake Flora

Lake Fauna

Available Nutrients

AgricultureNutrient/Sediment Load

Fish Community State

Water Quality

Plants Algae

Decomposers

Hydrology

Drainage Patterns

Nutrient Levels

Zooplankton

Non-PermeableSurfaces

Development Activity

Economic Benefits

Food

Recreation

Urban Development

Climate Change

Paper 1

Lake Stressor Ratings

2011

Lake Stressor Ratings

2012

Lake Stressor Ratings

2011 2012

Lake

Land

Streams

SocietyLake Flora

Lake Fauna

Available Nutrients

AgricultureNutrient/Sediment Load

Fish Community State

Water Quality

Plants Algae

Decomposers

Hydrology

Drainage Patterns

Nutrient Levels

Zooplankton

Non-PermeableSurfaces

Development Activity

Economic Benefits

Food

Recreation

Urban Development

Climate Change

Paper 2

Paper 1

Key Action Items

Causal lake system models-Current Knowledge, Hypotheses, Theory on lake system dynamics?-Evaluate models w/ historical and sentinel lake data, refine as understanding increases w/ new data.

Define research question, or management goals for MN lakes-Is lake meeting management goals? Optimal/Preferred aquatic community? Likelihood of meeting goals in future?-Specific research question is critical for tailoring indicator set for robust inference on the status of the fishery, the crucial/integrative component of lake systems (i.e. in DNR FAW view, plus fish can be viewed as ‘ultimate’ expression of system health)

Let us now search for the end of the rainbow…

Choose indicators that address phenomenon of interest and give insight into what factors are driving changes.

(e.g. fish IBI for community status, plus Nutrient levels, plant/zoop community IBIs, non-perm indicator for inference on drivers of change in fishery community).

Also may want to choose indicators for inference on status at a variety of spatio-temporal scales

(immediate local conditions, to long-term basin outlook).

In any case, indicator selection must be tailored to answer the specific research question.

Indicator Sampling and the SPDWant to incorporate indicator sampling in split panel design for local, regional, & statewide inference on status of MN lakes (may be current status, trends, statistical analyses, or causal modeling).

Likely have a range of sampling intensities, definition of status should be flexible enough to allow status estimation from disparate sources (while accounting for sample selection procedure and the potential biases or imprecision in any given estimate).

Intensely sampled lakes (Large lakes, sentinel lakes)Lake survey dataRandom sampling‘Free’ data

Can adjust effort to optimally collect information needed for management/status evaluation purposes

Utilize new sampling to test and refine causal network models (monitoring and modeling connected by management)

STATE

PRESSURE

RESPONSE

Biotic Community ShiftViolation of Clean Water Act

Riparian BuffersManagement InterventionDevelopment Regulations

Conservation Reserve ProgramOutreach and education

Non-Permeable SurfaceFertilizer usageAltering flow of waterWarmer tempsVariable precipNon-native invasionMacrophyte removal

DRIVING FORCE

IMPACT

Economic GrowthPopulation GrowthClimate change

Disrupted hydrological regimesIncreased Nutrients & SedimentWarmer waterLower Dissolved OxygenLoss of physical structure

Lake

Land

Streams or surficial flow

Society

Lake Flora

Lake Fauna

Available Nutrients

Ag stressors

Nutrient Load

Fish Community State

Water Quality

Plants Algae

Decomposers

Hydrology

Drainage PatternsNutrient Levels

Zooplankton

Devel. Stressors

Development Patterns

Economic Benefits

Food

Recreation

Stressors

Climate Stressors

SedimentsPaper 1

Paper 2