Unit 07 · Ocean Ecosystems
An ocean ecosystem is a community of living things plus the physical world it lives in — and the ocean holds many. This unit tours the big ones: coral reefs, estuaries where rivers meet the sea, kelp forests and the open ocean, and the deep sea with its hydrothermal vents. You trace how energy flows through each — from producers up to apex predators, and from chemosynthetic microbes where sunlight never reaches — and how species live together through symbiosis. Mastery means you can read an ecosystem as a web of feeding and partnership, and you know the deep sea teems with life rather than lying empty.
| Criterion | Not yet | Approaching | Mastered |
|---|---|---|---|
| Major ocean ecosystems | Pictures the ocean as one uniform habitat. | Names a reef or the deep sea but cannot describe what defines each. | Distinguishes the major marine ecosystems — coral reefs, estuaries, kelp forests, the open ocean, and the deep sea with its hydrothermal vents — by their physical conditions and the life they support. |
| Food webs & energy flow | Cannot trace who eats whom. | Draws a food chain but not a web, and misses the energy lost at each step. | Maps a marine food web from producers to apex predators, explains the energy lost up the chain, and identifies chemosynthesis as the base of the food web at hydrothermal vents. |
| Symbiosis & interactions | Treats every species as living alone. | Names symbiosis but cannot give a marine example. | Explains mutualism and other close interactions with real cases — coral and its zooxanthellae, cleaning stations on a reef — and predicts what happens when a partnership breaks down. |
| The deep sea (life without sunlight) | Believes the deep sea is lifeless. | Knows life exists deep but not how it survives without sunlight. | Explains that the deep sea teems with adapted life — running on chemosynthesis and sinking marine snow, not photosynthesis — and names adaptations to cold, dark, and pressure. |
| Lab technique (community survey) | Counts organisms without a method or a defined area. | Uses a quadrat but places it carelessly or skips species. | Runs a clean tide-pool or reef community survey with a quadrat — sampling a defined area, identifying species with a key, and recording abundance and diversity. |
| Integration (cross-domain) | Treats the science as isolated facts; makes no cross-domain connection. | Names a link to history, reading, or writing but cannot defend why it matters. | Connects the unit to its anchor across History · Reading · Writing (plus chosen electives) and defends why the connection matters. |
“At the vents there’s no sunlight, so the base of the food web is chemosynthesis — bacteria turning chemicals into food — not plants. On the reef the coral gives its zooxanthellae a home and gets sugars back; break that partnership and the coral bleaches. My quadrat counts showed the reef flat was far more diverse than the sand.”
“The deep sea is empty because nothing can live down there. Symbiosis is… two animals together? I just counted whatever I saw in the tide pool.”
You demonstrate this unit through the tide-pool or reef community survey plus short oral checks where you reason from your quadrat data aloud — not a multiple-choice test. A criterion counts as mastered only when you can both run the survey and explain the food-web and symbiosis biology behind it. Mastery is demonstrated, not awarded.
A 5-page clipboard packet — unit overview, key terms, the mastery rubric, anchor examples, and a score sheet you can print and grade against.