K-2

Local Ocean Food Chains

Implement this lesson:

Use this lesson when discussing animal ecosystems, habitats, or other environmental TEKs. This lesson can be used as part of a larger local theme i.e. Oceans Week. It can also be used for a food chain themed day. The duration of this lesson can vary based on student and teacher needs.

Learning Objective:

Students will be able to learn about food chains in local saltwater habitats. They will create an art project using their knowledge.

Texas Essential Knowledge and Skills (TEKS)

Science TEKS

K.10(B) identify basic parts of plants and animals

K.10(A) sort plants and animals into groups based on physical characteristics such as color, size, body covering, or leaf shape

1.9(B) analyze and record examples of interdependence found in various situations such as terrariums and aquariums or pet and caregiver

1.10(A) investigate how the external characteristics of an animal are related to where it lives, how it moves, and what it eats

2.10(A) observe, record, and compare how the physical characteristics and behaviors of animals help them meet their basic needs

2.10(B) observe, record, and compare how the physical characteristics of plants help them meet their basic needs such as stems carry water throughout the plant

2.10(C) investigate and record some of the unique stages that insects such as grasshoppers and butterflies undergo during their life cycle

ELA TEKS

K.3(B) use illustrations and texts the student is able to read or hear to learn or clarify word meanings

K.5(B) generate questions about text before, during, and after reading to deepen understanding and gain information with adult assistance

K.5(E) make connections to personal experiences, ideas in other texts, and society with adult assistance

1.9(D) recognize characteristics and structures of informational text, including: (ii) features and simple graphics to locate or gain information

1.6(C) make and correct or confirm predictions using text features, characteristics of genre, and structures with adult assistance

2.6(B) generate questions about text before, during, and after reading to deepen understanding and gain information

2.6(I) monitor comprehension and make adjustments such as re‐reading, using background knowledge, checking for visual cues, and asking questions when understanding breaks down

Overview:

Marine Food Chains in Texas Gulf Coast Bays

The golden rule of marine food chains especially in our bays is ‘if it can fit in its mouth, it will eat it.’ This means everything will everything if able and placement in the food chain changes as an animal gets older.

The bays along the Texas Gulf Coast—like Corpus Christi Bay, Galveston Bay, and Matagorda Bay—are full of life. These shallow waters support marine food chains, where each living thing is connected by what it eats and what eats it. These food chains are a key part of the bay ecosystem and help keep it healthy.

What Is a Food Chain?

A food chain is a series of steps that show how energy moves from one living thing to another.

The sun is the starting point for all food chains
Producers (like plants and algae) make their own food using sunlight
Consumers eat plants or other animals
Decomposers break down dead plants and animals into nutrients

Step 1: Producers (The Base of the Food Chain)

Phytoplankton – tiny floating algae that do photosynthesis
Seagrass – grows underwater in shallow bays
Salt marsh grasses – like cordgrass that grow along shorelines
These producers use sunlight, water, and carbon dioxide to make energy-rich food

Step 2: Primary Consumers (Herbivores)

Zooplankton – tiny animals that eat phytoplankton
Grass shrimp – eat algae and detritus
Blue crabs (young) – eat bits of plant matter
Snails – graze on algae
These animals eat producers and become food for larger animals

Step 3: Secondary Consumers (Carnivores)

Small fish – like pinfish, anchovies, and mullet
Shrimp and juvenile crabs
Fiddler crabs and small predators
They eat zooplankton, small crustaceans, or herbivores

Step 4: Top Predators (Tertiary Consumers)

Spotted sea trout, red drum, and flounder – popular game fish
Dolphins – eat fish and squid
Ospreys and pelicans – dive for fish
Octopuses – eat crabs, clams, and fish
These predators help keep populations balanced

Step 5: Decomposers

Bacteria and fungi break down dead plants and animals
Detritivores like worms and some crabs help recycle nutrients
This helps nutrients return to the water and soil, supporting new plant growth

Why It Matters

Food chains show how all life in the bay is connected
When one link is weakened (like overfishing or pollution), the whole chain is affected
Healthy food chains support:
- Biodiversity
- Fisheries
- Coastal communities
Protecting wetlands, seagrass beds, and clean water helps keep these chains strong

Fun Facts

Some animals, like sea turtles and crabs, change their place in the food chain as they grow
A food web is made of many connected food chains
Bays act like nurseries for young fish and shrimp
A drop of bay water can contain thousands of phytoplankton
Storm runoff and pollution can harm the lowest levels of the food chain, affecting everything above

Possible Books:

Who Eats What? by Patricia Lauber
Pass the Engergy Please! by Barbara Shaw McKinney
Ah! I am Full! by Eun-Sook

Procedures:

Introduce local food chains by asking what students know about them. Write what students say down in a possible KWL chart.
Watch a video, read a book, or use slideshow to teach students about food chains.
Complete the art projects
Read a book on food chains
Possibly finish KWL chart

Mouth in a Mouth Canvas Painting

Canvas
Paint and paintbrushes
Images of local animals

Reference Craft

Questions to Ask:

What is a food chain?
What is a predator? prey?
What is an apex predator?
What does an animal or plant need to survive in an ecosystem?
What determines if something is living or non living?
What is a producer? Consumer?decomposer?
How do living things rely on other living things within their ecosystem to survive?

K-2