TLE 8 AFA W4D4: Sustainable Aquaculture (Part 1)

🎯 Learning Goals – Day 4

By the end of the lesson, learners should be able to:

1. Describe different aquaculture methods used in fish farming.
2. Compare the advantages and disadvantages of selected aquaculture practices.
3. Explain how proper aquaculture methods contribute to sustainable fisheries development.

🧩 Key Ideas & Terms – Day 4

• Aquaculture – The farming of aquatic organisms, including fish, crustaceans, mollusks, and aquatic plants.
• Intensive Aquaculture – A method where fish are raised in high densities, requiring artificial feeds and aeration.
• Extensive Aquaculture – A method that relies on natural food production in ponds, lakes, or lagoons with minimal human input.
• Semi-Intensive Aquaculture – Combines natural food with supplementary feeding and moderate management.
• Pond Culture – Raising fish in man-made or natural ponds with controlled stocking, feeding, and harvesting.
• Cage Culture – Raising fish in cages or enclosures placed in rivers, lakes, or coastal waters.
• Pen Culture – Similar to cage culture but with enclosures fixed to the bottom of a water body, usually larger in area.
• Hatchery – A facility where fish are bred, hatched, and raised in controlled environments before being transferred to grow-out systems.
• Stocking Density – The number of fish stocked in a given area, influencing growth, health, and survival.
• Carrying Capacity – The maximum number of fish that a water body or system can support without harming the environment.
• Integrated Aquaculture – A practice where aquaculture is combined with agriculture, such as using animal manure to fertilize ponds.
• Polyculture – Farming of two or more species together to maximize resource use and reduce waste.
• Monoculture – Farming of a single species in an aquaculture system.
• Sustainable Aquaculture – Practices that balance productivity with environmental and social responsibility.

🔄 Quick Recall / Prior Knowledge – Day 4

Quick Recall: Multiple Choice

Directions: Choose the correct answer.

1. Which aquaculture method relies mainly on natural food and minimal human input?
   a) Intensive
   b) Semi-Intensive
   c) Extensive
   d) Cage
2. Raising fish in enclosures placed in rivers or lakes is called:
   a) Pond culture
   b) Hatchery culture
   c) Pen culture
   d) Cage culture
3. Which practice involves raising two or more species together?
   a) Monoculture
   b) Polyculture
   c) Integrated aquaculture
   d) Intensive aquaculture
4. What does stocking density refer to?
   a) The type of fish food used
   b) The number of fish per area of water
   c) The weight of harvested fish
   d) The cost of aquaculture production
5. Which practice combines aquaculture with agriculture (e.g., using manure as fertilizer)?
   a) Integrated aquaculture
   b) Monoculture
   c) Hatchery system
   d) Cage culture

Show Answer

1. c) Extensive
2. d) Cage culture
3. b) Polyculture
4. b) The number of fish per area of water
5. a) Integrated aquaculture

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Prior Knowledge Check – Short Response

1. Have you seen fish raised in ponds, cages, or pens in your community? Which one is most common?
2. Why do you think some farmers combine aquaculture with agriculture?
3. Do you think raising too many fish in a small space is good or bad? Why?

Show Answer

1. (Answers vary – ponds are common in rural areas, cages near lakes, pens in coastal waters.)
2. To recycle resources, reduce waste, and increase productivity.
3. Bad – it can lead to poor water quality, disease, and fish deaths.

📖 Explore the Lesson – Day 4 (3 Pages)

Introduction: Why Learn About Aquaculture Methods?

Aquaculture plays a major role in providing food, jobs, and income around the world. In the Philippines, fish like tilapia, milkfish (bangus), and shrimp are important for local diets and exports. But not all aquaculture is done in the same way. Farmers use different methods and practices depending on the environment, available resources, and goals. Understanding these methods helps us choose the most sustainable and productive options.

1. Extensive, Semi-Intensive, and Intensive Aquaculture

Extensive Aquaculture

• Relies mainly on natural food such as plankton, algae, and small organisms found in ponds, lakes, or lagoons.
• Farmers add very little input except for occasional fertilization.
• Stocking density (number of fish per area) is low.
• Advantages: Low cost, less labor, environmentally friendly.
• Disadvantages: Low production and growth is slower.
• Example: Milkfish in coastal ponds where fish feed naturally on algae.

Semi-Intensive Aquaculture

• Combines natural food with supplementary feed such as rice bran or formulated feeds.
• Requires moderate management and some use of fertilizers.
• Stocking density is medium.
• Advantages: Higher yield than extensive systems, balanced costs.
• Disadvantages: Requires more labor and monitoring.
• Example: Tilapia raised in ponds where farmers both fertilize and feed fish.

Intensive Aquaculture

• Fish are raised in high densities with constant feeding using commercial pellets.
• Requires aeration, frequent water exchange, and strict monitoring.
• Stocking density is high.
• Advantages: Very high production, faster growth.
• Disadvantages: Expensive, risk of water pollution, and higher disease outbreaks.
• Example: High-value species like shrimp or grouper in tanks or cages.

Comparison Table

Type	Feeding	Stocking Density	Cost	Yield	Example
Extensive	Natural food	Low	Low	Low	Milkfish in coastal ponds
Semi-Intensive	Natural + Supplementary feed	Medium	Moderate	Medium	Tilapia in ponds
Intensive	Commercial feeds	High	High	High	Shrimp or grouper in tanks

2. Pond, Cage, and Pen Culture

Pond Culture

• One of the most common practices.
• Fish are raised in natural or man-made ponds.
• Water levels are controlled, and fish can be fed and monitored easily.
• Advantages: Easy to manage, suitable for many species.
• Disadvantages: Requires land, risk of flooding and water quality issues.
• Example: Tilapia and catfish in backyard ponds.

Cage Culture

• Fish are raised in cages placed in rivers, lakes, or coastal waters.
• Water flows naturally through the cage, providing oxygen.
• Farmers can monitor feeding and growth closely.
• Advantages: Uses existing water bodies, easy harvesting.
• Disadvantages: Risk of pollution, fish escapes, and disease spread.
• Example: Milkfish cages in Laguna de Bay.

Pen Culture

• Similar to cage culture but larger enclosures are fixed to the bottom of lakes or coastal areas.
• Allows fish more space but still under control.
• Advantages: Higher yield than cages, more natural feeding.
• Disadvantages: Expensive to set up, limited to large bodies of water.
• Example: Tilapia pens in lakes.

3. Hatchery Systems

• Hatcheries are specialized facilities where fish are bred and hatched under controlled conditions.
• Fry (baby fish) or fingerlings are later transferred to grow-out systems like ponds or cages.
• Advantages: Ensures steady supply of healthy fry, improves survival rate.
• Disadvantages: Expensive to operate, requires skilled workers.
• Example: Shrimp hatcheries in Cebu and tilapia hatcheries in Central Luzon.

4. Stocking Density and Carrying Capacity

• Stocking density refers to how many fish are raised in a given space. Too many fish can cause stress, poor water quality, and diseases. Too few fish means lower production.
• Carrying capacity is the maximum number of fish that a system can support without harming the environment. Farmers must monitor water quality, oxygen, and waste levels.

5. Integrated and Polyculture Systems

Integrated Aquaculture

• Combines aquaculture with agriculture or livestock farming.
• Example: A farmer raises tilapia in a pond and uses manure from livestock to fertilize plankton for natural food.
• Benefits: Recycles waste, lowers costs, increases productivity.

Polyculture

• Raising two or more species in the same system.
• Example: Tilapia, catfish, and prawns together in a pond.
• Benefits: Reduces waste, makes better use of resources, increases total yield.

Monoculture

• Raising only one species.
• Easier to manage but higher risk if disease or problems occur.

6. Sustainable Aquaculture Practices

• Sustainability means balancing production with environmental care. Good practices include:
• Avoiding overstocking and pollution.
• Using organic or natural feeds when possible.
• Practicing proper waste management.
• Conserving biodiversity and protecting water quality.

Key Message:
Aquaculture methods vary depending on the goals and resources of farmers. Choosing the right method can improve food production, protect the environment, and support sustainable fisheries.

References

• FAO. (2020). Aquaculture Production Systems. https://www.fao.org
• BFAR Philippines. (2022). Philippine Aquaculture Overview.
• WorldFish. (2021). Sustainable Aquaculture Practices. https://www.worldfishcenter.org
• SEAFDEC. (2023). Innovations in Asian Aquaculture.

💡 Example in Action – Day 4

Worked Example: Choosing an Aquaculture Method
Jun is a young farmer in Laguna. He wants to start raising tilapia but is unsure whether to use extensive pond culture or cage culture in the nearby lake. He considers his options.

Option A – Extensive Pond Culture

• Uses natural food like algae and plankton.
• Low input cost since fish feed on what grows naturally in the pond.
• Lower yields, so Jun may not earn much in the short term.
• Less risk of pollution, more eco-friendly.

Option B – Cage Culture

• Requires cages, feeds, and more monitoring.
• Produces higher yields and faster growth.
• Risk of fish escapes, pollution, and diseases if cages are overcrowded.
• Higher income if managed well.

Decision and Action
Jun decides to start with semi-intensive pond culture. He uses natural pond food but also gives rice bran and formulated feeds. This way, he balances costs and production. After a year, he plans to expand and try cage culture with proper training.

Lesson from Jun’s Example
Aquaculture methods must fit the farmer’s resources, goals, and environment. There is no “one-size-fits-all.” The best method is the one that balances productivity, cost, and sustainability.

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Now You Try!

Scenario:
Ana owns land near the coast. She wants to raise milkfish. She has two choices: build ponds or invest in pens in the bay.

Questions:

1. What are the advantages of pond culture for Ana?
2. What are the disadvantages of pen culture?
3. If Ana wants long-term sustainability, which method would you recommend and why?

Show Answer

1. Pond culture advantages: Easy to manage, uses natural food, lower pollution risk.
2. Pen culture disadvantages: Expensive setup, risk of storms damaging pens, possible pollution.
3. Recommendation: Pond culture, since it is more manageable, eco-friendly, and sustainable for a beginner.

📝 Try It Out – Day 4

Practice 1 – Multiple Choice

Directions: Choose the letter of the correct answer.

1. Which aquaculture method uses high stocking density and commercial feeds?
   a) Extensive
   b) Semi-Intensive
   c) Intensive
   d) Integrated
2. Which culture method raises fish in enclosed areas fixed to the bottom of lakes or coastal waters?
   a) Pond culture
   b) Pen culture
   c) Cage culture
   d) Hatchery
3. What is the term for raising only one species in a system?
   a) Monoculture
   b) Polyculture
   c) Integrated aquaculture
   d) Semi-Intensive
4. Which aquaculture system combines aquaculture with agriculture, such as using manure for pond fertilization?
   a) Monoculture
   b) Integrated aquaculture
   c) Hatchery system
   d) Cage culture
5. Which aquaculture system ensures a steady supply of healthy fry and fingerlings?
   a) Pond culture
   b) Hatchery
   c) Intensive culture
   d) Pen culture

Show Answer

1. c) Intensive
2. b) Pen culture
3. a) Monoculture
4. b) Integrated aquaculture
5. b) Hatchery

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Practice 2 – True or False

Directions: Write T if the statement is true, F if false.

1. Extensive aquaculture is expensive and requires high feed input.
2. Polyculture allows two or more species to be farmed together.
3. Pond culture is the most common aquaculture method in the Philippines.
4. Intensive aquaculture has no risk of pollution.
5. Integrated aquaculture helps recycle resources.

Show Answer

1. F (It is low cost with minimal input)
2. T
3. T
4. F (It has higher risk of pollution)
5. T

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Practice 3 – Situation Analysis

Directions: Write one possible solution or explanation for each.

1. A farmer wants high yield but has limited funds for feeds. Which method is suitable?
2. A lake community suffers from pollution due to overcrowded cages. What should be done?
3. A farmer raises tilapia and prawns in the same pond. What method is this, and why is it beneficial?
4. A hatchery produces too many fry but survival is low. What should the farmer improve?
5. A farmer wants to protect the environment while maintaining income. Which practice should be emphasized?

Show Answer

1. Semi-Intensive culture, as it balances cost and yield.
2. Reduce stocking density, follow carrying capacity, improve waste management.
3. Polyculture – it maximizes resources and reduces waste.
4. Improve water quality, feeding practices, and disease management.
5. Sustainable aquaculture practices like integrated aquaculture and proper waste control.

✅ Check Yourself – Mixed Quiz (10 Items)

Part A – Multiple Choice (1–4)

1. Which aquaculture method has the lowest cost but lowest yield?
   a) Intensive
   b) Extensive
   c) Semi-Intensive
   d) Integrated
2. Which method requires high capital, aeration, and constant feeding?
   a) Hatchery
   b) Extensive
   c) Intensive
   d) Pen
3. Raising fish in cages in lakes or rivers is known as:
   a) Pen culture
   b) Cage culture
   c) Pond culture
   d) Hatchery culture
4. Which practice involves raising two or more species together in one system?
   a) Monoculture
   b) Integrated aquaculture
   c) Polyculture
   d) Intensive aquaculture

Part B – True or False (5–7)

5. Semi-Intensive aquaculture uses both natural food and supplementary feed.
6. Hatcheries are facilities that breed and supply fingerlings.
7. Intensive aquaculture is risk-free because it uses commercial feeds.

Part C – Short Answer (8–10)

8. State one advantage of pond culture.
9. Give one disadvantage of pen culture.
10. Why is carrying capacity important in aquaculture systems?

Show Answer Key

Part A – MCQ

1. b) Extensive
2. c) Intensive
3. b) Cage culture
4. c) Polyculture

Part B – T/F

5. True
6. True
7. False (It has risks of pollution and disease outbreaks)

Part C – Short Answer

8. Advantage of pond culture: Easy to manage, suitable for many species, natural food availability.
9. Disadvantage of pen culture: Expensive to set up, risk of storm damage, pollution.
10. Carrying capacity ensures that fish populations do not exceed what the environment can support, preventing stress and pollution.

🚀 Go Further – Enrichment & Remediation Activities (Day 4)

Activity 1 – Aquaculture Method Infographic

Task: Create an infographic comparing extensive, semi-intensive, and intensive aquaculture.

• Show feeding practices, stocking density, cost, and yield.
• Use icons or drawings to make it clear and colorful.

Sample Output

A chart showing:
- Extensive: low input, low yield.
- Semi-Intensive: moderate input, medium yield.
- Intensive: high input, high yield.

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Activity 2 – Role Play: Farmer Consultation

Task: In pairs, act out a scene where one student is a farmer choosing between pond, cage, or pen culture, and the other is a fisheries technician giving advice.

Sample Output

Farmer: “I want higher production but I have little money.”
Technician: “Try semi-intensive pond culture first, then expand when you have more capital.”

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Activity 3 – Debate: Monoculture vs. Polyculture

Task: Divide the class into two groups:

• Group A defends monoculture as easier to manage.
• Group B defends polyculture as more sustainable.
• Each group must give at least 2 arguments.

Sample Output

Group A: “Monoculture is simpler, less complicated to manage.”
Group B: “Polyculture recycles waste, maximizes resources, and increases yield.”

🔗 My Reflection – Day 4

Option A – 3-2-1 Reflection

Write your answers in your notebook:

• 3 things I learned about aquaculture methods and practices.
• 2 advantages of practicing sustainable aquaculture.
• 1 question I still have about aquaculture systems.

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Option B – Reflection Checklist (Tabular)

Copy and answer in your notebook by putting ✔ Yes or ✘ No.

Reflection Statement	Yes / No
I can describe different aquaculture methods.
I can explain the difference between extensive, semi-intensive, and intensive systems.
I can give at least one advantage of pond, cage, or pen culture.
I understand why stocking density and carrying capacity are important.
I value sustainable aquaculture for food security.

🎣 Take the Aquaculture & Fish Capture Quiz