Lesson 3: Crisis Analysis and Intervention Research

What caused the algae bloom?
Which factor exceeded system capacity?
What interventions are possible?
What are the trade offs of each intervention?

Algae bloom
Nutrient overload
Trade off
Filtration
Cleaner organisms
Light limitation
Input reduction
Mechanical intervention

HS LS2 1
Use mathematical representations to support explanations of factors affecting carrying capacity.

HS ETS1 3
Evaluate a solution to a complex real world problem based on prioritized criteria and trade offs.

Science and Engineering Practice, Engaging in Argument from Evidence
Science and Engineering Practice, Analyzing and Interpreting Data

Crosscutting Concept, Cause and Effect
Crosscutting Concept, Stability and Change

Day 1: Revisiting Proposals

Students bring back their Phase 1 intervention proposals.

They evaluate whether their initial reasoning aligns with new nitrogen and capacity understanding.

Students categorize each proposed intervention as:

Addresses input
Increases processing
Reduces accumulation
Superficial adjustment

Day 2: Evidence Based Defense

Students select one primary intervention and justify it using:

Nitrogen cycle understanding
Carrying capacity reasoning
Observed parameter data

They must explicitly state:

How this increases processing capacity or reduces input.

Day 3: Risk and Trade Off Analysis

Students analyze possible unintended consequences:

Adding algae eaters may increase bioload
Adding plants may alter oxygen dynamics
Reducing feeding may impact fish health
Increasing filtration may change flow rate

Students refine their intervention choice.

This segment ends with a class decision on what intervention will be implemented.

DOK 2
Summarize causes of algae blooms and identify possible solutions.

DOK 3
Analyze trade offs between intervention strategies and justify a selected solution using evidence.

Approaches DOK 4 when students synthesize system data and intervention reasoning.

Farmers and aquaculture managers must choose interventions carefully to avoid harming livestock.
Lake management teams implement nutrient reduction strategies to prevent harmful algal blooms.
Engineers must balance effectiveness with sustainability and unintended consequences.

Algae is purely harmful and should be eliminated completely.
One solution fixes all problems permanently.
More filtration automatically solves imbalance.
Interventions have no side effects.

https://docs.google.com/document/d/1siFIsOAs45CxuUlyJt9dNRdT70eTva14fJMeE1qXHPk/edit?usp=sharing%20

Intervention Proposal

Students submit a written justification identifying the chosen intervention, explaining why it addresses the limiting factor and acknowledging potential trade offs.