Ocean Food Web Worksheet for Learning Marine Ecosystems

Let’s solve this ocean food web worksheet step by step.

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## 🌊 Direction 1: Label the parts and connect with arrows

This is a food web, which shows how energy flows from one organism to another. Arrows point from the organism being eaten → to the organism that eats it.

Step 1: Identify the roles

- Producers: Make their own food (usually plants or algae).
➤ Seaweed (the green plant) — this is the primary producer.

- Primary Consumers: Eat producers.
➤ Zooplankton (tiny organisms in the circle) — eat phytoplankton (not shown, but implied), and sometimes seaweed.
➤ Shrimp — often eat algae/seaweed and zooplankton.

- Secondary Consumers: Eat primary consumers.
➤ Cod fish — eats shrimp and zooplankton.
➤ Penguin — eats fish like cod and squid.
➤ Squid — eats shrimp and small fish.

- Tertiary/Quaternary Consumers (Top Predators): Eat secondary consumers.
➤ Killer Whale (Orca) — eats seals, penguins, squid, and even other whales.
➤ Walrus — eats shellfish, shrimp, and sometimes fish.
➤ Seal — eats fish and squid.
➤ Whale (Baleen whale) — eats krill/zooplankton (filter feeder).

> Note: The large gray whale shown is likely a baleen whale (like a humpback or gray whale), which eats plankton. The killer whale is the toothed predator.

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Step 2: Draw the arrows (energy flow)

Here’s how to connect them logically:

1. Seaweed → Zooplankton *(if zooplankton eats algae)*
OR
Seaweed → Shrimp

2. Zooplankton → Shrimp
Zooplankton → Cod
Zooplankton → Baleen Whale *(filter feeder)*

3. Shrimp → Cod
Shrimp → Squid
Shrimp → Walrus

4. Cod → Penguin
Cod → Seal
Cod → Killer Whale

5. Squid → Penguin
Squid → Seal
Squid → Killer Whale

6. Penguin → Killer Whale

7. Seal → Killer Whale

8. Walrus → ? (Usually not prey for others here — top consumer)

> 💡 *Note: In real life, walruses are not typically eaten by killer whales, but in simplified food webs, they may be included as prey for educational purposes. However, based on biology, killer whales usually target seals, penguins, and fish — not walruses.*

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## ❓ Direction 2: Answer the questions

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Q1. Name two prey of killer whales.

✔ Seals and Penguins

*(Also acceptable: Squid, Cod, or even other whales — depending on the ecosystem. But based on this diagram, seals and penguins are clearly shown as prey.)*

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Q2. What do penguins eat?

✔ Fish (like cod) and Squid

*(Penguins are carnivorous seabirds that primarily eat small fish, squid, and krill. In this food web, cod and squid are shown as their prey.)*

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Q3. Name the producer of the food web.

✔ Seaweed

*(Producers are organisms that make their own food via photosynthesis. Seaweed is the only plant shown — it’s the base of this food web.)*

> ⚠️ Note: Sometimes phytoplankton are the true base, but since they’re not drawn, seaweed is the correct answer here.

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Q4. What is the role of the cod in the food web?

✔ Secondary consumer

*(The cod eats primary consumers like shrimp and zooplankton, and is itself eaten by tertiary consumers like penguins, seals, and killer whales. So it occupies the second consumer level — secondary consumer.)*

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## ✔ Final Answers Summary:

Direction 1:

Draw arrows as follows (from prey → predator):

- Seaweed → Shrimp
- Zooplankton → Shrimp, Cod, Baleen Whale
- Shrimp → Cod, Squid, Walrus
- Cod → Penguin, Seal, Killer Whale
- Squid → Penguin, Seal, Killer Whale
- Penguin → Killer Whale
- Seal → Killer Whale

*(Optional: Add arrow from Zooplankton → Seaweed if you consider detritus cycling, but usually not needed at this level.)*

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Direction 2:

Q1. Seals and Penguins
Q2. Fish (cod) and Squid
Q3. Seaweed
Q4. Secondary consumer

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Let me know if you’d like a visual sketch of the completed food web! 🐋🐟🦐