Giant Kelp
(Macrocystis pyrifera)

General information
Copyright Julianne E. Steers

Phylum: Phaeophyta
Size: Up to 100 feet
Range: Santa Cruz to Turtle Bay, Mexico and along the temperate coasts of South America and New Zealand
Notes: Over the years, there has been an increasing ecosystem imbalance. The extirpation of the southern sea otter during the late 1800s and, more recently, heavy fishing of spiny lobster and sheephead – all major predators on sea urchins – has let the urchin populations blossom. With more sea urchins around, the kelp has not had the opportunity to grow. Other causes for the decline of kelp include wastewater discharge and erosion from hillside development that puts enough dirt into the oceans to bury the substrate – and tiny new kelp plants.