The Disappearing Kelp Forests of San Clemente Island

I was recently diving at San Clemente Island. The profound lack of giant kelp forests was a striking contrast to what I am used to seeing over 25 years of diving at the island. Under ideal conditions, giant kelp can grow about 2′ per day (the fastest growing plant on Earth), but it does require relatively cool water to really flourish. In 2014, water temperatures were higher than normal, leading to poor growth conditions. The kelp has not recovered, and if an El Nino that is predicted to occur in 2015 comes to pass, it is almost certain to cause whatever kelp forests are at the island to recede considerably. Here are two images, from above the southeastern tip of the island (“Pyramid Head”) looking northwest along the axis of the island, shot in September 2010 (top, healthy thick kelp forests appear in brown, from Pyramid Cove in upper left around Pyramid Head point and up the eastern side of the island) and July 2014 (almost total absence of giant kelp forests). These two images are crops, click on either to see the original composition.


See more photos of San Clemente Island, photos of giant kelp forests, and aerial photos. Cheers and thanks for looking!