"Why did the sea urchin population grow out of control along the Pacific Coast?
O Fishermen stopped harvesting sea urchins from the coast.
O The waters warmed, providing an optimal breeding environment.
O Sea otters were their main predator but were overhunted.
O There was plenty of food in the form of kelp in the habitat.

Sea otters were the main predator of sea urchins along the Pacific Coast, but they were overhunted in the 18th and 19th centuries, leading to a decline in their population.

The absence of sea otters allowed the sea urchin population to grow unchecked, resulting in the overgrazing of kelp forests, creating 'urchin barrens.'

This uncontrolled sea urchin population growth was further exacerbated by a decrease in sea otter numbers due to predation by killer whales, causing a chain reaction affecting the marine ecosystem.

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