May 2007

By John Francis

Photography by Brandon Cole

After certification in a 49-degree Virginia rock quarry, Nancy Caruso moved to Florida and spent four years diving its coral reefs while earning a degree in marine biology. By then, she must have thought she'd seen the worst and best of diving. But that was before coming to California eight years ago and diving its giant kelp forests. It was a revelation. Now she says, "I like kelp diving best of all. I usually just lie there on the bottom and look up at the sunlight. A kelp forest is like a cathedral with stained glass windows. It's awesome." Cathedral, redwood forest, jungle-the analogies most often used to describe a kelp forest point to the intimate relationship between diver and dive site in kelp. "You don't just swim past the scenery," says Rick Baker, senior program director at Dana Point's Ocean Institute. "You swim through it. We're like birds flying through the forest."

Like jungles, kelp forests-with their slithery, vine-like tentacles-can be intimidating at first. But penetrating a kelp forest, exploring its pathways and clearings, is actually pretty easy once you know how. Kelp is only a plant, after all-no muscles, no claws, no suckers, no brains. The "grasp" of the kelp is easy to avoid or defeat if you just know how.

The Descent

It's essential to enter a kelp forest from below the almost-solid mass that floats on the surface. In most species of kelp, particularly the Macrocystis pyrifera, or giant kelp that dominates in the classic California kelp forest, individual fronds of kelp ascend vertically from the bottom to the surface, where they spread out in a dense canopy. The diver's entrances to the kelp forest are below the surface. Here's how to get down safely:

Don't step off the boat into kelp. Reposition the boat (or wait until it swings away from the kelp) so you can step off into clear water.

Look down before you descend. Sometimes kelp does not reach the surface. The water can look clear from the boat, but there may be a mass of kelp 10 feet below, and you may need to swim horizontally until you can descend in clear water.

Descend vertically. You have less chance of snagging kelp if your body is vertical in the water.

Look around as you descend. "You always want to know where the kelp is," says California dive instructor Linda Van Velson. Generally it stands in vertical columns, but individual strands straggle off in all directions and can get caught between your tank and your back.

Find natural openings. Natural gaps can occur. When you get below the canopy, start looking for an opening in the kelp wall that's big enough for easy entry.

Entering the Forest

A usable opening into the kelp needs to be wide enough to fit through without much risk of snagging, though a few strands can be pushed aside as you enter. Here's how:

Step one: Be sure you are neutrally buoyant. In the kelp you will need to be able to maintain your altitude without finning. You should be trimmed so you're horizontal, too. You will occasionally swim through an especially small hole, and if you drag your fins, they will catch kelp.

Step Two: Put your hands together in front of you, palms outward.

Step Three: Make one fin kick, then glide into the kelp.

Step Four: As you pass through the opening, sweep the kelp aside and behind you, as if you were walking through a bead curtain.

Step Five: Keep your fins together and stationary, with your legs fully extended behind you, until you have passed into a clearing. If you need to kick again, make small ones with your ankles only. It's not just a matter of not kicking the kelp. Finning hard stirs the water the kelp is floating in and can actually suck the kelp toward your fin.

One more consideration: Does this opening go anywhere? You're a lot like an 18-wheeler going down an alley without the option of backing up: You shouldn't enter unless you can see ahead of you that there's a clearing large enough to turn around in, or an exit as big as your entrance. Turning around in kelp requires a bigger clear space than you might think, because your fins sweep a large area. One method of turning around is first to get your fins underneath you by bringing your knees to your chest.

Exploring the Forest

A diveable kelp forest will have a number of clearings connected by a network of trails. You'll want to follow these trails. "Pay attention to where you are in relation to the edge of the kelp so you can get out," says Julia Mariottini, senior aquarist at the Monterey Bay Aquarium. Do not get too far from the outer wall of the forest, as any trail can become a blind alley and you may need a way out.

The forest is often thinnest near the bottom, so if your way forward gets tight, you may find more room down near the holdfasts.

You and your buddy will need to swim single-file. That fact makes it easy for buddies to get separated from each other in kelp. The leading buddy should go slowly. Whenever he reaches a clearing large enough to do it without tangling himself, he should turn to look behind him and make visual contact with his buddy.

Watch your air supply. The canopy is an overhead environment, though it can be penetrated in an emergency. Because you can't expect to swim side-by-side in kelp, air sharing with a buddy is difficult.

Tangled Up in Kelp

The first hint that you've caught some kelp will be when you slowly come to a halt even though you're still finning. If that happens, freeze. Your instinct will be to turn and look behind you, but that is likely to gather more kelp stands-"like turning a fork in spaghetti," as Scuba Lab Director Bill Kendig puts it. Instead, do this:

Get exactly neutral if you're not already. If you rise or fall in the kelp, you will collect more of it.

Now, without twisting your body, reach behind your head to your first stage, a common place to catch kelp. If you find it, try to lift it up and away. If your first stage is clear, you've probably caught the kelp with a fin. Again, without twisting your torso, pull that knee to your chest, reach for the strand of kelp and release it.

If you can't lift kelp away from where it's caught, you probably can't break it by just pulling on it. But you can double it back on itself until it snaps. This is usually a better solution than getting out a knife.

If you can't clear a kelp tangle by yourself, signal your buddy for help. But your buddy needs to be careful when approaching you so that he doesn't get caught in it too. If you can't clear yourself and your buddy has disappeared, your last option is to take off your scuba unit so you can see the tangle and clear it. Move slowly and be very careful to keep a hold on your BC, especially if you use integrated weights.

Surge

Kelp thrives near the surf zone, so the water, and the kelp, is likely to be in constant motion. Pathways can open and close, and the surge can send you where you don't want to go-into thick kelp. Keep an opening or clearing "downstream" of you. On the other hand, you can use the surge for effortless propulsion through the forest. Coast forward with the surge, then grab the kelp plants to hold you on the backwash. Grab a handful of fronds, not just one, near their holdfast.

Ascending in Kelp

As with any overhead environment, you'll need to go horizontally for some distance before you can go vertically.

Which way is clear water? From the middle of the kelp forest, it may not be obvious. If there is a noticeable slope to the rocky bottom, a good bet is to go downhill. Generally, the rocky reef will run down to sand flats, which will be clear of kelp.

Once you break through the kelp wall to clear water to make your ascent, the kelp can be an asset instead of a hindrance. If you ascend next to the kelp, you can use it as a visual indicator of your ascent speed or even grab a handful of fronds to stop your ascent or steady you at your safety stop. Remember, though, that kelp usually spreads out as it nears the surface. So before you leave your safety stop, look up to be sure there's clear water above you.

Doing the Kelp Crawl

What if you have to ascend into the kelp canopy? The mass of floating kelp is really a "soft" overhead because you can push through it. The wet kelp on your head and shoulders can be heavy, so you may need all the buoyancy your BC has.

Now what? You're in the middle of a paddy of floating kelp, with many pounds of the stuff wrapped around your tank valve, your first stage, your neck. How do you get out of there? If you have enough air left, the best bet is to redescend, feet first, in the same place where you surfaced. The kelp floats, so as you go down, most of it will lift off you. Then you can go horizontally out of the kelp before ascending again.

If redescending isn't possible, the next-best option is the "kelp crawl." This is a method to pull yourself over the top of the kelp canopy.

Step one: Inflate your BC fully so you're as high in the water as possible, and clear yourself of kelp as best you can.

Step two: Reach forward with both arms extended and push the kelp below and behind you as you pull yourself across the top of the kelp. Trail your fins, don't kick them, as they would only get tangled. Take it slowly; thrashing as if you were going for gold in the 50-meter butterfly will only exhaust you.

Reaching for the Light

In a kelp forest of Macrocystis pyrifera, as in any canopy forest, sunlight is life, and the race goes to the tallest. Water filters out much of the sunlight, so living on the bottom is practical only in clear, shallow water.

Though kelp is a type of algae and therefore one of the most primitive plants, it has evolved a novel solution to the problem of reaching through 100 feet or more of water to the light: natural buoyancy compensators. The gas bladders called pneumatocysts float the plant up to the light, so a fragile weight-bearing trunk is unnecessary.

Water also offers plants a benefit in that it carries far more nutrients than does air. Kelp, like all algae, absorbs nutrients directly from the ocean, needs nothing from the ground and has no roots or vascular system.

Kelp can live as a free-floating plant like the bacteria and pond scum it is related to, but it would soon wash ashore and die. So kelp also evolved an anchoring system. Thin stalks, flexible and elastic so that they aren't easily broken by wave action, grip the rocks. Each anchor, the "holdfast," can be as big as four feet across, according to Orange County marine biologist Nancy Caruso, and produces hundreds of stalks.

The plant rarely begins deeper than 100 feet, but can easily be twice as long, as the bulk of it spreads out on the surface forming the distinctive canopy.

Kelp Talk

Haptera Individual spaghetti-like "roots." They are not really roots, as they gather no nutrients and only grip the rock.

Holdfast The tangled mass of haptera that forms the base of a single plant.

Stipe An individual stalk growing from the holdfast. Each is about the diameter of a pencil. Many can grow from one holdfast.

Blade The "leaves." Unlike terrestrial leaves, both sides of the blades produce photosynthesis. They die in about a month, drop off and feed bottom-dwellers.

Bladder The floats that hold the plant up. Properly called pneumatocysts, they are filled primarily with carbon monoxide.

Frond A stipe with its bladders and blades. Each can be 200 feet long, with much of its length lying on the surface, tangled in the canopy.

Gear Up For Kelp

Streamline: Your first consideration is to avoid "kelp grabbers"-anything dangling or projecting from your body that could catch kelp. Strap your knife to the inside, not the outside, of your calf. Tape down the ends of your fin straps or cut them off. Take the snorkel off your mask and strap it to the inside of your thigh or under your BC. Rig your console and octopus as close to your body as possible, or tuck them under your BC. And, of course, don't dive with any gear you don't need.

Knife: A blade with a serrated edge, or shears, works best for cutting kelp.

Pony bottle: In recognition of the fact that the kelp canopy is an overhead environment, consider a fully redundant air supply.

Weight belt: As do wreck divers, some kelp divers use belts with two buckles. One is backup in case the other is pulled open by a strand of kelp.

Crowded with Life

The shade below the canopy keeps the lower forest thin, leaving trails and clearings. It also creates specialized habitats for creatures that can make do with less. The opportunities for interaction between them, and for predation from outside the kelp forest, make it home to an estimated 800 species of life.

Nosing among the fronds are sheephead, greenling, señoritas, bass, perch and rockfish. Hunters like barracuda and yellowtail patrol the edges, and it's not uncommon to meet head-on with a sea lion or seal rocketing through channels in the kelp.

Down among the holdfasts are bat stars, brittle stars, crabs, and urchins feeding on dead leaves that drift down from the canopy. Urchins also feed on live kelp. Chewing through the holdfasts like goats, they can leave a desert behind. Look for:

Giant kelpfish. Almost exactly the shape and color of a kelp blade, the giant kelpfish puts its nose up to a stipe and hangs, swaying in the surge and waiting for prey. Though it can be two feet long, a diver may not see it until he startles it into motion.

Kelp crab. Also colored like the kelp blades, it can reach six inches across and stands tippy-toe on the blades.

Bryozoans. They look like snowflakes or white moss encrusting the blades but are actually colonies of animals.

Norris's topsnail. With its bright red foot, it slowly climbs a kelp frond, grazes its way out to the end of a blade and falls off. When it hits the bottom it, crawls to another kelp plant and begins climbing again.