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Marine Biology D—Ocean Systems — Ecosystems, Reefs & Conservation
by MonaHow the ocean works as a system — and what happens when we push on it. Learners trace energy through food webs, explore the ocean's great habitats from vents to reefs, and analyze the science behind overfishing, warming, acidification, plastic pollution, and recovery.
Library
Ecosystems & Food Webs
Lesson 1
The Otter That Saved a Forest
An entire underwater forest off Alaska vanished while the sunlight, water, and nutrients stayed exactly the same — and the prime suspect never ate a single plant.
StartLesson 2
The Ten Percent Problem: Why Food Chains Are Short
Sunlight powers everything in the sea, yet almost none of it reaches a shark. Where does all that energy go?
Locked till you take the prior lessonLesson 3
Upwelling: Why Fisheries Crowd Into Tiny Corners of the Sea
A handful of small coastal zones supply a huge share of the world's fish catch. What makes those spots so special — and so fragile?
Locked till you take the prior lessonLesson 4
Webs, Not Chains
Real ocean food webs are tangled, redundant, and strange. Discover why that tangle decides whether an ecosystem bends or breaks.
Locked till you take the prior lessonLesson 5
The Sun Never Reaches Here: Life at Hydrothermal Vents
Miles down, in crushing darkness, entire ecosystems thrive without a single ray of sunlight. What are they eating?
Locked till you take the prior lessonLesson 6
The Polar Paradox: Plenty of Nutrients, Not Much Life — Until All at Once
Polar seas are loaded with the nutrients that fuel life, yet stay nearly empty for months. Then something extraordinary happens.
Locked till you take the prior lessonLesson 7
A Feast That Lasts Fifty Years: Whale Falls and Marine Snow
The deep sea is almost always starving — except when something enormous dies above it. Follow the food as it sinks.
Locked till you take the prior lessonReefs & Coastal Habitats
Lesson 8
Darwin's Paradox: Rainforests in a Desert Sea
Coral reefs explode with life in water that should starve them. Darwin spotted the paradox — can you solve it?
Locked till you take the prior lessonLesson 9
Builders and Bulldozers: How a Reef Stays Alive
A reef is a constant war between animals that build rock and animals that grind it to sand. Tip the balance and the whole thing collapses.
Locked till you take the prior lessonLesson 10
Kelp: The Forest That Grows Half a Meter a Day
No roots, no flowers, no wood — yet kelp builds towering underwater forests faster than almost any plant on land. How?
Locked till you take the prior lessonLesson 11
Mangroves, Salt Marshes & Estuaries: Where the Land Feeds the Sea
Trees that drink seawater and flooded grasslands quietly export enormous amounts of food — and shelter — into the open ocean.
Locked till you take the prior lessonLesson 12
The Crashing Shore: Life on the Rocky Intertidal
Every few seconds, a wave tries to kill everything living on this rock. Discover how life organizes itself in the surf zone.
Locked till you take the prior lessonHuman Impacts & Conservation
Lesson 13
Fishing Down the Food Web
In 1992, one of history's richest fisheries vanished almost overnight. Trace how it happened — and why nobody saw it coming.
Locked till you take the prior lessonLesson 14
The Ocean's Fever: What Actually Kills a Bleaching Coral
A one-degree spike triggers a cellular crisis inside coral tissue. Uncover the mechanism — and why some reefs survive it.
Locked till you take the prior lessonLesson 15
The Other CO2 Problem: Acid Seas
Carbon dioxide is quietly changing seawater chemistry itself. What does that mean for anything that builds a shell?
Locked till you take the prior lessonLesson 16
The Myth of the Garbage Island: Plastics, Microplastics & Bioaccumulation
Sail to the Great Pacific Garbage Patch and you might see almost nothing. So where did the plastic go — and what is it doing there?
Locked till you take the prior lessonLesson 17
Rebuilding the Ocean: Protection That Works
One overfished Mexican bay came roaring back to life. What made it work — and can the trick scale to the whole ocean?
Locked till you take the prior lesson