Implement this lesson:
During the habitat unit, students will understand the need to protect oyster habitats. They will also understand how dredging can harm their habitat. Or 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 oyster themed day. The duration of this lesson can vary based on student and teacher needs.
Learning objectives:
Students will be able to learn about one of the most common animals found in local saltwater habitats, the bull shark. They will create an art project using their knowledge.
Texas Essential Knowledge and Skills (TEKS)
Science TEKS
3.1(A): Ask questions about organisms, objects, and events in the environment.
3.10(A): Collect information from observations using simple equipment.
3.9(A): Explore how adaptations enable organisms to survive in their environment.
3.15(A): Organize information to create a visual display or map.
3.7(B): Communicate and justify a solution.
3.11(B): Identify and discuss how different forms of energy can be used.
3.14(A): Identify the importance of conservation.
3.8(A): Collect and record data.
4.11(A) Identify and explain advantages and disadvantages of using Earth’s renewable and nonrenewable natural resources such as wind, water, sunlight, plants, animals, coal, oil, and natural gas
4.11(B) explain the critical role of energy resources to modern life and how conservation, disposal, and recycling of natural resources impact the environment
4.11(C) determine the physical properties of rocks that allow Earth’s natural resources to be stored there
4.12(A) investigate and explain how most producers can make their own food using sunlight, water, and carbon dioxide through the cycling of matter
4.12(B)* describe the cycling of matter and flow of energy through food webs, including the roles of the Sun, producers, consumers, and decomposers
4.12(C) identify and describe past environments based on fossil evidence, including common Texas fossils
4.13(A) explore and explain how structures and functions of plants such as waxy leaves and deep roots enable them to survive in their environment
4.13(B) differentiate between inherited and acquired physical traits of organisms
5.10(A) explain how the Sun and the ocean interact in the water cycle and affect weather
5.10(B) model and describe the processes that led to the formation of sedimentary rocks and fossil fuels
5.10(C) model and identify how changes to Earth’s surface by wind, water, or ice result in the formation of landforms, including deltas, canyons, and sand dunes
5.11(A) design and explain solutions such as conservation, recycling, or proper disposal to minimize environmental impact of the use of natural resources
5.12(A) observe and describe how a variety of organisms survive by interacting with biotic and abiotic factors in a healthy ecosystem
5.12(B) predict how changes in the ecosystem affect the cycling of matter and flow of energy in a food web
5.12(C) describe a healthy ecosystem and how human activities can be beneficial or harmful to an ecosystem
5.13(A) analyze the structures and functions of different species to identify how organisms survive in the same environment
5.13(B) explain how instinctual behavioral traits such as turtle hatchlings returning to the sea and learned behavioral traits such as orcas hunting in packs increase chances of survival
🦪 Impacts of Dredging on Oysters
Nueces Bay is located close to Corpus Christi, Texas. It is primarily an oyster reef driven system with fresh water input provided by the nearby Nueces River. Although showing relatively high productivity, it has been affected by dredging and industrial pollution. Dredging and limited fresh water input has caused the redistribution of sediments and species throughout the bay. Due to these environmental changes and increased turbidity, many of the species have adapted to alternate food sources.
1. Physical Damage
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Dredges can crush or dislodge oysters from the reef.
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Young oysters (spat) are especially vulnerable because they’re more fragile.
2. Sediment & Smothering
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Dredging stirs up mud, sand, and silt.
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This extra sediment can bury oysters, blocking them from food and oxygen.
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Fine particles can clog their gills, making it harder to breathe and feed.
3. Habitat Loss
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Oysters need hard surfaces (like shells or rocks) to attach and grow.
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Dredging can strip away these surfaces, leaving soft, unstable bottoms.
4. Water Quality Changes
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Sediment clouds the water, reducing light for underwater plants like seagrasses, which are part of healthy oyster ecosystems.
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Dredging can also release pollutants or nutrients trapped in the mud, harming oysters.
5. Long-Term Population Decline
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Destroying reefs reduces the number of oysters that can reproduce.
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Without strong reef structures, future generations have fewer places to settle.
⚖️ Summary
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Short-term: Oysters may be killed or stressed by direct damage and sediment.
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Long-term: Reef habitats may disappear, leading to declining oyster populations and loss of the ecosystem services they provide (like filtering water and protecting shorelines).
Possible Books:
- Pearlie Oyster by Suzanne Tate
- Olly the Oyster by Elaine Ann Allen
- Oliver the Oyster by JB Auchter
- Why the Oyster Has the Pearl by JB Auchter
Materials
- clear bins
- sand
- simple hydraulic or tube vacuum
- optional paper with illustration materials
- different items that sink to represent different animals (pony beads, bb, nickels, etc)
- pitchers of water
- empty bowl
Lesson Plan:
Engage:
Show students pictures of the Lydia Anne Channel, Inner Coastal, or show video Waterway. Ask students if those are man made or natural. What do they think about those waterways? Are they good or harmful? How do the animals react to the waterways being built? How are the waterways built?
Explore:
Conduct the experiment
- Put students in groups. Each group gets a clear container
- Students fill bottom of container with sand
- Have students decide what each item represents for example nickels are oysters, pony beads represent fish, etc. The students place the different items all over the sand layer wherever they want. Make sure to add lots of oysters for oyster beds. Have students draw a sketch of where each item is.
- Gently add water over the sand. This is now a wetland ecosystem.
- Use the hydraulic and students gently suck out the sand along the middle of the sand bed. As students are sucking up the sand ask them what they observe (ie the water is getting cloudy, they cannot see the animals anymore, etc)
- After a period of time where students have created their canal. They will now suck out the water. The water removal is just to see what has changed with the items representing creatures.
- After the water is removed, have students draw a picture of what everything looks like. Students discuss what has changed since dredging began.
Explain:
Students https://www.youtube.com/watch?v=JXGMEE1BVWA&t=1027s
Elaborate:
Students research the latest of the Harbor Bridge and if any animals or habitat will be impacted
Evaluate:
Students write a paragraph describing their observations and discoveries