Dry Kelp found on the beaches of Point Reyes, California?

Question

http://www.terragalleria.com/pictures-subjects/seaweed/picture.seaweed.cabc10900.html

Hi, does anyone know about kelp? I found some of the dry kelp last weekend in the Point Reyes, California. I was suprized to see how big those kelps were. The above link will show you the kelp I saw. I wonder how old are those kelps. Does anyone know?

Answer 1

What you have pictured is bulb kelp (Nereocystis luetkeana), which is most likely what you saw.  Bulb kelp is found as far south as Pismo Beach.  The other large kelp species is Giant kelp (Macrocystis pyrifera); whits a described range from Mexico to Ano Nuevo, although it is routinely reported North of Ano Nuevo.  Giant kelp inhabits the Channel Islands National Marine Sanctuary as well as the Monterey Bay National Marine Sanctuary, where giant kelp and bull kelp coexist.  In the more northern Gulf of the Farallones and Olympic Coast National Marine Sanctuaries, as well as several coastal marine sanctuaries, kelp forests are comprised of predominantly bull kelp.

Regarding age, kelp survival is positively correlated with the strength of the substrate. The larger and stronger the rock on which it is anchored, the greater the chance for the kelp to survive.  Winter storms and high-energy environments easily uproot the kelp and can wash entire plants ashore.  Giant kelp can live up to seven years, and bulb kelp has a similar lifespan