Ocean Ecology
Year Level: 7-9
Tuning In: Sample Activities
Prior knowledge investigation
Give students time to respond to each of the following questions.
- What and where are world’s oceans?
- How large and deep are they?
- Why are they described as biologically diverse ecosystems?
- List as many different specific groups of animals and plants that inhabit the Southern, Pacific or Indian Oceans which surround Australia.
- What are the major associations/relationships that exist between animals in these ocean waters?
- What are major requirements for an ocean community to exist and thrive?
Mapping
Invite students to create maps to show the oceans that surround Australia.
Preparing to find out: Sample Activities
Essential knowledge development
To survive in any environment, an organism must be able to:
1) Tolerate the physical conditions
2) Satisfy it requirements for food, oxygen, water, shelter and space
An ocean habitat is very different from terrestrial habitats. Consider the following:
Oxygen
How do marine animals breathe under water?
How are gills different from lungs?
What other ways do animals extract oxygen from water?
Light
Light does not penetrate very far into seawater, and the various parts of the light spectrum are absorbed at different rates. Red is among the first colours to be absorbed which is why blood appears green under water. Competition among marine plants and animals for light at or near the surface of the sea can be great.
Which organisms need light?
How deep do sunlight and the colours of the spectrum penetrate seawater? Buoyancy
The weight of liquid displaced by a floating object is equal to the weight of the body (be it a fish, a human, a ship, or a stone). Because of this buoyant force, objects will sink if they are heavier than the mass of the surrounding fluid, and will rise if they are lighter. If an object weighs the same as an equivalent volume of the fluid, it will be in equilibrium and remain motionless. You experience buoyancy in seawater.
Investigate the purpose of buoyancy control devices such as swim bladders in fish, oil-laden livers in sharks, and the Buoyancy Compensation Devices (BCDs) that scuba divers wear. Viscosity
Water offers greater resistance to movement than air because of its density.
What adaptations have sea creatures undergone to maximise their efficiency in seawater? Salinity
Due to the process of osmosis, seawater tends to dehydrate our bodies if we are immersed for too long.
What evolutionary adaptations have marine animals developed to avoid this problem? Cause and effect wheels
Ask students to create ‘cause and effect’ wheels to evaluate the contribution of environmental factors to change within populations and communities in our oceans. The wheels can be enlarged and displayed in the classroom. |
