Beauty Beyond the Seaweed: Giant Kelp, Macrocystis pyrifera

Updated: Jun 29, 2021

people on beach
Happy beach visitors

Many people, both scuba divers and non-divers alike, have never experienced the stunning beauty of kelp. Referred to by many as seaweed, most remember running along the beach as a child feeling the slimy leaves of seaweed stuck to their feet. Experiences that cause lifelong “heebie jeebies” of what lies beneath the sea rarely vacate the subconscious. Braver souls, who have triumphed their fears to embrace their adventurous side and have taken the plunge into the depths as scuba divers or snorkelers, might have experienced kelp in a different way. Any water-bound human who has swam through a kelp forest has experienced that moment when seaweed wraps around their foot and brings them right back to that day on the beach long ago when that pesky kelp frond nearly wrangled them into the depths by their tiny little foot.

giant kelp floating on ocean surface
Giant Kelp floating on the surface near Big Sur, CA

Whether you’re a member of one or the other, hopefully you can appeal to some like myself, who has chosen to see the beauty kelp has to offer. I’ve even turned it into art a time or two.

In the Northern hemisphere, Giant Kelp is mostly found on the Pacific coast all the way from Alaska to Baja, California along rocky shorelines. While it looks like a plant, kelp is actually a form of large brown algae and doesn’t have any roots at all. It has root-like grabbers, called “holdfasts” that wrap themselves around rocks on the ocean floor. From all the way to the bottom of the sea, kelp can range from 6 to 100+ feet tall as it reaches toward the sun.

giant kelp holdfasts
The Giant Kelp's Holdfasts

Holdfasts should be thought of as more like anchors than a root system. While they may look like roots above the sand, the holdfasts do not absorb any nutrients. They are simply meant to hold the kelp stem sturdy and in place. Instead of having roots, kelp gets all of its nutrients through photosynthesis from its fronds (leaves).

Since holdfasts are anchored to rocky ocean bottoms, kelp must literally grow and reach toward the sun in order to survive. In order to achieve this, it must grow as tall as it can to float at the surface where many of its fronds can have real estate as close to sunlight as possible.

channel islands kelp forest
Beautiful Kelp Forest by Jamie Peterson

As snorkelers and scuba divers are well aware, organisms in the ocean often need a little help to float. Giant kelp has a gas bladder, scientifically called “pneumatocyst”, that helps make it float. Each frond of Giant Kelp has its very own pneumatocyst that gives it buoyancy. The closer kelp grows to the surface, the more sunlight each frond absorbs, making it stronger and healthier. Strands of Giant Kelp have been known to live as long as 7 whole years! It lives best in cool clear water (where light can shine deeper) with stable temperatures between 42-72 degrees Fahrenheit. When lots of kelp grows together, it’s what we call a “kelp forest”. Just like in the dry forest, where the tops of the trees form a canopy, kelp forests do the same. This allows protection for several species of fish to hide, and several others to actually eat the kelp as food.

Did you know, kelp has been recorded to grow as quickly as 1 to 2 feet in a single day?

Kelp that breaks free from its stem usually sinks to the bottom of the ocean where it becomes food for other organisms. Sometimes, as we remember from the opening paragraph, it can wash ashore where it can meet our feet during those pleasant walks on the beach!

As you can see here, kelp is nothing to fret about and is actually a bit of an ocean necessity. Below are photographs of California Giant Kelp taken on two different occasions among the Channel Islands near Catalina. Whenever I have the opportunity to swim around this amazing ocean life, I always do my best to “play” with the lighting I have available combined with my camera settings to create underwater art to show readers just like you at the surface. Specific camera settings allow the background of the photograph on the left entitled, ”What Lies Beneath” to look like it was taken at night. However, it was actually taken during the middle of the day in only 40-45 feet of water! I purposely used only a single strobe to create a shadow effect by illuminating only the left side of the kelp. The next photograph entitled, “Reaching for Life” (also available in Black & White) was also used with specific camera settings combined with underwater lighting that allowed me to create an intentional blurred effect of the background and kelp fronds. These settings allowed me “freeze” only certain parts of the kelp, in this case the pneumatocysts, keeping them crisp and in-focus in the photograph.

Please follow the photographic links to go to the gallery where more photographic art is available for your viewing pleasure!

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