CopyRight @ 1997
I was on a night dive in Hawaii with a guide who had been the
head diver for the Hilton for 10 years and had certifications for
just about everything, ratcheda, ratcheda, ratcheda... I asked him
if he had been kelp diving. "Ya and I'll never do that again". Huh?
I love the kelp beds.
The cold nutrient rich waters of California support a wide
variety of seaweeds. Seaweeds, as they are called, are Algae. There
are basically 3 kinds of Algae that make up the seaweeds. A fourth,
the Golden Algae, are actually types of plankton. The seaweed type
of Algae are called the Reds, Greens and Browns. The big kelps are
a type of Brown Algae called the Laminareas. The Reds and Greens are
smaller and tend to be more common in the shallower waters.
In the intertidal areas, the Red and Green Algae make strange
shapes and colors growing everywhere on all the rocks. Different
species have characteristic depths and conditions where they are
found. Past about 30 feet, it is the Browns that give the
characteristic golden color to California reefs.
Have you ever wondered what those little pink articulated things
are that grow on just about every shallow rock in California. Those
are the Red Algae, Rhodocladia and Rhodophera. Their hard outer
shell is made of calcium taken from the seawater.
The term kelp can mean a number of things depending on where
you are. From the Arctic to Antarctic it is commonly used to refer
to the large local algae, whatever that is. In California it is
used to refer to the big brown algae, primarily Macrocystis
pyrifera. It is the fastest growing plant in the world. Up to 24
inches a day has been claimed. It has air bladders to make it float
and can form thick mats on the surface in up to about 100 feet of
water. It can have heavy thick rope like "stalks" with fronds 5
inches wide by 36 inches long. Its growing end produces delicate
beautiful patterns of miniature leaves.
Talk California Kelp and you are talking the language of
Wheeler J. North. He was the researcher awhile back that made what
is considered the definitive study of kelp forest ecology. It is a
big book you can skip unless you are really interested. He did make
some points to note though.
Kelp only grows on rock, except above Santa Barbara, where it
seems to grow in the mud. It is used for food by only about 3
fish. Indirectly it is used by other fish to allow them to extend
their range by letting them know where the rocks are. They follow
the kelp down to the rocks like divers do. Fish population is
dependent on the rocks under the kelp, not the kelp. In a rocky
kelp forest, the fish population may be up around 35 pounds per
acre. This is also true in a rocky reef where there is no kelp such
as Guadeloupe Island. In the Santa Barbara area, where the bottom
under the kelp is not rocky, the fish are about 3 pounds per acre.
Fish need hiding places from predators and kelp helps, but is just
not what it takes.
The invertebrates, urchins and mollusks (abalone) are the ones
that really eat the kelp. They mostly eat the kelp leaves that have
broken off and drifted to the bottom. Over populations of urchins
may destroy a kelp bed by attacking the holdfasts of the kelp
plants.
Kelp beds provide incredibly beautiful diving. Only silliness
will get you stuck in them. They may grow like multi-stalked huge
trees from a single large holdfast or they may grow distributed as
single strands coming up every 6 inches from the rock. The single
strand ones are the beds that get the thickest. It is true that
they have great tensile strength to resist wave action, but they
are really not individually strong. They will give a panicked diver
a good opportunity to kill themselves, but a common practice in
classes is to teach students how easy it is to break them by
folding them over. Some instructors make the students bite the kelp
to show how fragile it really is. Simple swimming skill will make
it rare that you get a strand entangled on your gear. If I cannot
easily pull kelp off of my gear, I tend to keep swimming to break
it. Divers in kelp areas learn to wear their knife on the inside of
their leg, tape their fin straps together and set up the rest of
their gear so that it is not likely to catch on the kelp.
When returning to a boat, it is easiest to save enough air to
swim under the kelp, but a "kelp swim" will allow a person to easily
cross the densest paddy. A kelp swim is basically a "dog paddle"
where you bring your hands out of the water to shove the kelp down
in front of you as you go over it.
Kelp grows the entire length of the California coast, where
there are rocks to anchor to. Warm water and pollution has thinned
out the kelp some. It used to be common to find paddies that were 2
or more feet thick and covering miles. Dense beds like this are
unusual now. Normally, it does not get too dark under the kelp, but
it can, especially if it is where many single strands grow on flat
rocks. It is beautiful and calm under the kelp. When the evening
wind blows, it flips over the fronds on the surface, making it
glisten in the sunset.
Kelp is a kind of Laminarea. That is, it is a member of the
family of Brown algae, Laminarealis. (sp) More common than the large
Bull Kelps are other species of Laminareas that are much smaller.
They tend towards cooler water than the Macrocystis. The typical
Laminarea is a holdfast, a strong stalk (commonly 18 inches tall) and
then leaves (called stipes) on top. I have seen them 6 feet tall near
Point Buchon, but those were extraordinary. They loosely look like a
small tree in design, except that instead of branches and many leaves,
it has essentially no branches and one or two large leaves. These may
grow in fields above flat rocks such that you must look carefully to
see anything under the canopy. It is exotic to drop right onto the
bottom and swim through these fields. Swimming above them, look
carefully as they move in the surge and you may see a kelp bass that
is trying to hide.
In many areas of boulders and broken rocks, the Laminareas grow
singly, well spaced on rocks, such that they make the perfect things
to grip while you relax as the surge pushes against you. They also
can be used as a pull handle to spring forward against whether there
is a surge or not. It is easier to pull against something solid than
it is to use fins to push against fluid water. With hands and fins,
you can really travel. It is best to grab the bottom of the stipe and
pull constantly, so as not to break the plant. I like to brachiate
when under water. These laminareas are beautiful in the way a healthy
garden is.
In areas where swell is generally negligible, like on the inside
of the islands starting at about 60 feet, is another Laminarea called
Elephant Ear kelp. This has a small stipe, perhaps 6 inches long, but
it has huge leaves. The single leaf, may be 2 feet wide and 30 feet
long. Obviously, any sizable surge would rip this loose. These sit in
a mat no more than 2 feet off the bottom. You cannot see anything
under them. Because it is so impenetrable, few divers go under it. It
makes for a fascinating dive though. Vis is usually no more than 4
feet, because at that distance, you see either rock or kelp no matter
how clear the water is. It can be a good place to hunt lobster,
especially at night, but grabbing a lobster that is resting on kelp is
near impossible, even with two hands. Often, Sculpin hang out in the
calm water under this kelp.
Above the central coast, another kind of Laminarea found
commonly in the lower intertidal zone, is the Sea Palm, Palmifera
californica. These greenish golden plants grow in dense groups on the
top of rocks, to a height of about 16 inches. Instead of just a couple
of leaves on the top, these have an abundant mop. They look like a
small palm tree. Their coloration and shape are pretty enough that I
always look forward to seeing them.
Kelp makes for wonderful diving.
Feather Boa