Giant kelp ecosystem dynamics — trophic cascades and canopy ecology
Giant kelp (Macrocystis pyrifera) can grow up to 60cm per day, forming underwater forests up to 50m tall that support over 1000 species. The kelp-urchin-otter trophic cascade is a classic ecology case study: sea otters eat urchins, which eat kelp holdfasts; without otters, urchin populations explode and create "urchin barrens" — rocky reef devoid of kelp. This was demonstrated dramatically after sea otters were hunted to near-extinction along the Pacific coast. Kelp forests also act as significant "blue carbon" sinks and buffer coastal communities from wave energy, making their conservation critical to ocean health.