Black Cormorant

Kelp Fields of the Poor Knights

The underwater kelp fields of the Poor Knights Islands are magnificent. The kelp is relatively short and branching: more like the sea palms of Southern California kelp, than like the macrocystis kelp that dominates the kelp forests. But, it is abundant. Underneath the low canopy is a carpet of sessile invertebrates, with fish of many stripes cruising through the shade.

Acid Kelp at Refugio Beach

Refugio seems to be coming back nicely from the oil spill -- or perhaps it's better than ever.  Quite a few fields of acid kelp are growing along the reef. To me this seems to be a positive sign. It has a nice dark-purple color. Often small fish, including groups of a few juvenile rockfish, hang out in hollows. I understand that it clears areas out, and then lets other things grow. I'm not sure what this kelp bass was doing.

City on a Kelp Blade

Life on a blade of macrocystis kelp at Naples. To me, a kelp leaf from close up looks like an aerial photograph of a city, with space divided up into various areas according to use and inhabitants. In this case, the lacy areas are bryozoans, while the spirals are nudibranch eggs. Some nudibranchs feed on bryozoans, so these may have laid eggs after snacking. The participants might see this as the remains of a Roman orgy, rather than a city.

In Voyage of the Beagle, Charles Darwin wrote of kelp: "Almost all the leaves, excepting those that float on the surface, are so thickly incrusted with corallines as to be of a white colour."

Kelp at San Clemente

The kelp at San Clemente was much thicker than it is near the more northerly Channnel Islands closer to Santa Barbara.  The stems were so closely spaced that a diver could not make his way between them without frequently catching a fin buckle on a stem. The kelp canopy covers the underwater sky in both places, but up north the holdfasts are huge, and from each comes a canopy for a large area. The canopies of the San Clemente kelp must be smaller.

Kelp in Shallow Water

Kelp in shallow water, at Channels, on the South side of Anacapa.

Kelp With Urchins: The Urchin Barrens

In many spots, urchins have devoured the bottom cover, leaving bare rock. These areas don't seem to be healthy for urchins either, because they are smaller than in areas with more abundant bottom life.

Kelp Canopy

Sunlight shining through the kelp canopy. On a clear day, the kelp forest seems to contain more light than an abovewater forest.

Krill in the Kelp Forest

Krill and black rockfish in a kelp forest, at San Miguel Island. Often, gray whales stop off at San Miguel to dine on the krill, on their way to the Northwest Pacific where they spend their summers.

Laputa

Often, kelp has enough buoyancy to lift the rocks that originally anchored it on the seafloor. Darwin wrote, in Voyage of the Beagle, "A few taken together are sufficiently strong to support the weight of the large loose stones, to which in the inland channels they grow attached; and yet some of these stones were so heavy that when drawn to the surface, they could scarcely be lifted into a boat by one person." In other cases, the rocks drop off, leaving the holdfast at the kelp's base without anyting to which to hold fast. They seem like the island of Laputa in Gulliver's Travels: floating from place to place above the Earth, supporting its disengaged citizens.

A Cloudy Day in the Kelp Forest

Although occasionally the kelp forest is beautifully clear, often suspended life in the water makes for cloudy conditions.