BIOL 213 LABORATORY: Eutrophication Study Guide

Understand Eutrophication: Define the term “eutrophication” and explain how this process occurs and its importance in aquatic ecosystems.
Hypothesis Development: Develop and test hypotheses regarding the impact of nutrient enrichment on various components in terrestrial and aquatic microcosms, such as terrestrial and aquatic plants, water chemistry, and aquatic microorganisms.

Lab Manual: Lab 3 Manual
Assignment Guidelines: Follow provided guidelines for assignments.
Supplementary Reading: Khan FA and Ansari AA. (2005) "Eutrophication: An Ecological Vision." The Botanical Review, 71(4), 449–482, available on D2L.

Aquatic vs Terrestrial Ecosystems: Despite being viewed as distinct, aquatic ecosystems (like lakes and rivers) are interconnected with terrestrial ecosystems, providing resources (e.g., fish as bear food) and allowing nutrient cycling.
Eutrophication Process:
- Defined as the enrichment of water bodies with nutrients from terrestrial ecosystems.
- Can occur naturally (e.g., from riverbank erosion) or be accelerated by human activities (cultural eutrophication).
Nutritional States:
- Oligotrophic: Healthy aquatic ecosystems characterized by low dissolved nutrient levels (oligo = few, trophic = relating to nutrition).
- Eutrophic: Aquatic ecosystems with high nutrient levels, often dominated by algae and surface plants, typically an undesirable state.
Nutrient Components:
- Primary nutrients include:
- Nitrogen (N): Essential for amino acids and proteins.
- Phosphorus (P): Important for DNA and energy transfer processes.
- Potassium (K): Critical for turgor pressure in plant cells and enzyme activation.
- Fertilizers contain three key numbers indicating the percentage of N, P, and K (e.g., 20–15–20).

Role of Cyanobacteria: Unlike green algae, cyanobacteria can fix atmospheric nitrogen into a usable form, thriving in environments deficient in nitrogen.
Nutrient Limitation: In many ecosystems, nitrogen availability is a key limiting factor for plant and algal growth, especially in agroecosystems.
Human Impact: Addition of fertilizers and animal waste enhances nutrient availability but often exceeds immediate plant uptake, leading to runoff of excess nutrients into water bodies.
Consequences of Eutrophication: Cultural eutrophication has become a significant issue in various aquatic ecosystems (reference: Carpenter et al., 1998).

Microcosm Setup: Participants will establish microcosms designed to investigate the effects of fertilizer application on both terrestrial and aquatic ecosystems.
- Chambers:
- Upper chamber simulates a terrestrial ecosystem (field) containing soil.
- Lower chamber simulates an aquatic ecosystem (pond) containing water.
- Both chambers designed with air holes for gas exchange.
Organisms Used:
- Terrestrial Plants: Grown in the upper chamber.
- Aquatic Plants and Phytoplankton: Grown in the lower chamber; includes cyanobacteria and eukaryotic algae.
- Phytoplankton serves as foundational organisms in aquatic food webs, demonstrating rapid population growth in response to increased nutrient availability.
- Zooplankton Introduction: Introduced into the lower chamber to feed on phytoplankton.
Expected Outcomes: After a few weeks, data will be collected on:
- Growth of terrestrial and aquatic plants.
- Changes in aquatic microorganism populations.
- Water quality alterations related to different fertilizer concentrations.

Eutrophication leads to ecological imbalances in aquatic environments.
Essential nutrients controlled by both natural processes and anthropogenic activities.
Eutrophic conditions favor algal blooms, which can disrupt aquatic life and water quality.
Understanding these processes is crucial for managing and protecting aquatic ecosystems.