Kelp (Seaweed)

Kelp forest (Ethan Daniels /

Kelp is a marine brown algae of the order Laminariales. Growing in coastal waters of colder ocean regions kelp forests form a highly productive ecosystem. The genera Macrocystis and Nereocystis have a very high growth rate, adding up half a meter per day under optimal conditions. They can reach a total length of 80 meters (260 feet).

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This supplemental online resource accompanies the book Scuba Diving Hand Signals by Lars Behnke, available on Amazon.