Awesome Algae

I love seaweed. Having grown up in a suburb of Detroit, I never thought I'd say that. As a kid on vacation, it was always just that nasty stuff that impeded my direct path from the warm sand to the ocean waves.  

As an avid diver here in southern California, I've come to love seaweed. Algae, actually. Which, as I discovered, is Latin for seaweed. I'll stick with algae, because I don't really think of what I'm about to describe as a "weed." 

Diving in these massive kelp forests is like walking through a forest on land.  The sun streams through the canopy and dances on the forest floor.

Unlike plants, kelp species do not have a true root system, which delivers nutrients from the ground up. They secure themselves to the rocky reef by means of a root-like structure called a holdfast. From the holdfast forms the main length-wise structure called a stipe. Dozens of leaf-like blades branch-off from the stipe, which are supported by gas-filled floats. The algae absorbs nutrients from its blades and energy from the sun through photosynthesis. 

This entire kelp structure is hanging on by a thread, perhaps separated from the reef by the sharp teeth of urchins. Once afloat, this will become home to many juvenile fish and will, in turn, attract game fish before it degrades or washes up on shore.

Anyone familiar with southern California diving knows that the star of the show is giant kelp (Macrocystis pyrifera). Not only is this awesome algae home to thousands of species, it is also an important ingredient in many of the things we consume everyday like toothpaste, ice cream, make-up, and more. You can often find it on the list of ingredients under the name alginate. Since it grows so quickly (up to two feet per day under optimal conditions), it is harvested commercially. It's found in just a few temperate locations around the world including, but not limited to, South Africa, South America, and New Zealand. 

A kelp crab greets me during a safety stop at Santa Barbara Island.

The kelp canopy is filled with critters that call it home. Countless species of fish use the canopy to find food and protection. Juvenile species can be seen by the dozens, schooling together and darting behind the nearest kelp blade at the sound of my bubbles.

The kelp forests are also home to some of the largest fish species, like this giant sea bass. 

Giant kelp isn't the only species, however. Another one of my favorites is the very distinctive elkhorn kelp (Pelagophycus porra). This species is typically found where the giant kelp leaves off,  which is around 60fsw. Although you won't find vast tall forests of this species, you can often see massive areas of the sea floor covered with its large blades.

A diver looking for torpedo rays in a forest of elkhorn kelp.

Smaller, more colorful coralline and various red algae splash the reef with color, which is most apparent in the shallow, sunlit areas of the reef.  Garibaldi (the California state marine fish) will build their nests with various species of red algae, forming a large red circular area on the reef.  

A garibaldi and red algae in the bright shallows of San Clemente Island.

A crevice kelpfish surrounded by red coralline algae.

Another distinct type of algae is the southern sea palm (Eisenia arborea). Its thick trunk or stipe, along with its strong holdfasts, allow it to withstand the forces of the intertidal zone. 

This female sheephead shows no fear and poses gracefully above a southern sea palm.

Southern California diving just wouldn't be the same without this awesome algae. So the next time you're diving in these waters, be sure to look around at the different species. You never know what cool critters you may find!

Be sure to catch my next post by simply entering your email address below where it says "Follow By Email."