Forests of Kelp

Kelp Forest Reef     Beyond the wave-swept, chaotic world of the shoreline lies a clandestine, mysterious world, the kelp forest.  Unlike sandy beaches and rocky tidepools, its treasures are concealed from all except those willing to brave the cool water with scuba equipment, and the myriad of creatures residing there.  At times serene, but sometimes a roiling, surge-swept cauldron, kelp forests cling to the coast along most of the Monterey Peninsula.     

     From a landlubber's perspective, a kelp forest hardly seems appealing.  Tourists may naively regard the floating, brown mats as unsightly intrusions on their grand oceanic views.  Ask any inhabitant of the kelp forest and you will undoubtedly receive a more enlightened response.  It seems that every creature residing in this realm has some connection to the seaweed we call giant kelp.  Indeed, the surface canopy barely hints at the diverse, bountiful world lurking beneath the gray waters.  Big Sur, Point Lobos, Carmel Bay, Monterey Bay -- surely among the most magnificent coastal vistas anywhere on the planet.  An equally wondrous undersea setting lies beneath the waves that line these fabled shores, still largely unspoiled by the imprint of humans. 

     For most visitors to the waters of Monterey Bay, a topside glance at the kelp canopy is the extent  of their view.  Boaters and kayakers gain a somewhat more revealing peek, particularly on those spectacular mornings when the surface is glassy smooth and the sun is not shrouded by coastal fog.   Lurking beneath the waves exists another truly magical yet largely hidden world, dominated by massive spires of giant kelp.  Few underwater scenes are more stunning than that of a healthy canopy, pierced by shimmering shards of sunlight.  This scene repeats countless times along the shores of the Monterey Peninsula, and much of the west coast of North America. 

     Giant kelp (Macrocystis pyrifera) thrives in nearshore habitats from Baja California to southern Alaska, as well as temperate waters of South America, South Africa and southern Australia.  All these areas are well endowed with rocky surfaces for attachment, and cool, nutrient-laden ocean water required by giant kelp.  Whereas the cold and surge create discomfort for scuba divers, they are a blessing to kelp and other seaweeds. 

     As depths exceed about ten feet, the majestic kelp forest can gain a foothold.  Capable of growing up to 100 feet in length, this gargantuan seaweed forms a living coastal band wherever rocky bottoms permit attachment.  Rather than using roots characteristic of terrestrial vascular plants, kelps employ finger-like holdfasts to secure a grip on hard substrates.  Rising from the holdfast are tangled thickets of tough, elastic stipes, which form the scaffolding for the leaf-like kelp blades.  Here is where photosynthesis produces food for the plant, using nutrients from the surrounding water in concert with sunlight.  Seaweeds lack the vascular system so vital to flowering plants, hence the need for continuous water motion to ensure a steady supply of required compounds.  Given the proper conditions, growth of a giant kelp frond can exceed a foot per day.  By late summer fronds form dense, nearly impenetrable canopy ceilings.  

     Gliding beneath the canopy, surrounded by towering spires of giant kelp, the feeling is one of being immersed in an undersea cathedral.  Hundreds of species of fishes and invertebrates ply their trades within this marine wonderland.  Unlike the gaudy, brightly lit aura of a coral reef, kelp forest scenes are more muted, at least from a distance. All is bathed in a diffuse, greenish light, thanks to the microscopic phytoplankton thriving in these nutrient-rich waters.  Animals in this cool environment also lead less frenetic lives and forgo the hectic activity schedules of coral reef denizens. 

     The water column hosts a medley of swimmers that seek more open spaces.  Massive throngs of blue rockfish hang languidly beneath the canopy, gently swaying in unison with the back and forth surge.  As with many other kelp forest dwellers, vulnerable larvae of rockfish are cast into the sea, spending their formative months facing the dangers of the open ocean.  A spunky gang of senorita wrasses zips by, nervously picking at tiny bits of invertebrate fodder on the kelp, under the watchful gaze of a school of blacksmith damselfishes.  By nightfall the wrasses will have imbedded themselves in the sand, secure from dangers of the dark.  A harbor seal calmly observes the proceedings while gracefully swimming through the scene.  Sometimes you might even see a more open ocean dweller, like a purple-striped or moon jellyfish that really would rather be somewhere else if it had a choice.  Even schooling fish like anchovies and herring make guest appearances in the confines of the kelp forest. 

     Numerous creatures conduct daily activities using giant kelp as their center of the universe.  Bryozoans and hydroids coat the blades by late summer like a dusting of snow.  Kelp crabs cling tenaciously to the sinuous fronds, eagerly waiting for passing bits of food.  Swarms of tiny mysid shrimp swim frenetically among the blades, ever careful not to stray too far from the protective enclaves.  Gaudy jeweled top shell snails glide up and down the stipes while grazing on encrusting invertebrates.  Cryptically colored pipefish, clingfish, kelpfish and juvenile rockfish lie hidden among the fronds, secure in their belief that predators cannot see them.  You can think of giant kelp as a living condominium. 

     Farther down, the tangled mats forming holdfasts harbor their own communities.  Careful examination will reveal a profusion of hidden creatures that shun the spotlight.  A single holdfast may house hundreds of brittle stars, given away only by their extended, feathery arms.  Worm lovers will delight in the thousands of polychaetes that colonize the inner dungeons of the mass.  Hydroids, tunicates and sponges conquer space on the initially barren outer turf.  Anemones and sea cucumbers often wedge their soft bodies in seemingly impossible positions to grab a precious spot.  Various predatory snails and gaily colored nudibranchs graze on the invertebrate gardens cultivated by the holdfast.  Small crabs appear to be trapped in a living jail, extending their claws for morsels of food.  Deep inside the labyrinthine structure, octopus, snapping shrimp and other shy kelp forest denizens find a comfortable home. 

     Ask someone about their feeling of what a coral reef is like, and bright, colorful fish and corals would typically come to mind.  Kelp forests seldom render such an impression.   The reality is somewhat surprising to most people, however.  Take a look at a healthy, surge-swept pinnacle wall and bland is hardly the word that comes to mind.  Colors of all shades, particularly reds, scream for attention.  Purple and pink hydrocoral, orange cup corals, strawberry anemones, rose anemones, volcano sponges, bryozoans, tunicates and a plethora of other colorful sessile forms create living tapestries of unrivaled beauty.  A bright patch of white stands out, revealing itself to be a living wall of white-plume anemones.  All of these sessile invertebrates, grounded for life, depend on plankton rich surge and current to make home deliveries for their meals.  Although not reliant on giant kelp, shallow rocky reef communities generally associate with kelp forests since each has similar goals -- clean, cool, nutrient-laden water with abundant sites for attachment.

     Vibrant strawberry anemones are among the prime artists painting this undersea canvas.  Pinnacle tops capped by patchwork quilts of violet, pink and red harbor different clones contesting for living space.  Within this dense thicket of life, myriad benthic creatures reside cryptically.  Aptly named painted greenlings, snubnose sculpins, cabezon, juvenile gopher rockfish and menacing wolf eels are some of the more familiar characters.  Plodding invertebrates, including chitons, jeweled top-shell snails, nudibranchs, sea cucumbers, urchins and a splendid array of colorful sea stars, relentlessly cruise the reefs in search of food. 

     Rivers of sand lie between the imposing rocky reef walls.  As you might expect, certain kelp forest creatures have devised ways to survive in this always shifting habitat.  The constant back and forth surge that blasts between the rocky reefs swirls the sand, always striving to bury those animals not equipped to deal with the onslaught.  Anemones, cup corals and other attached forms are at constant risk of being buried alive if positioned at the base of a rock wall.  Others, like tube dwelling worms, clams and tube anemones, have no problem with the challenge presented by shifting sand and easily stake claims in this dynamic habitat.  Flatfish appropriately known as sanddabs blend perfectly with the background, waiting to ambush tiny prey that unknowingly approach.  In the deeper sand flats just beyond the kelp bed, massive mating aggregations of squid deposit their contribution to the next generation.  Gardens of brilliant white egg masses attract hordes of patient predators, who dine on the spent female squid or wait for the eventual bounty of countless squid hatchlings. 

     All is not peaceful in this deceptively placid community.  Predators lurk in every corner, whether obvious types like toothy lingcod, or more devious forms such as nudibranchs.  Most kelp forest creatures exist under the continual threat of being consumed.  Small fishes warily keep their eyes open for the monstrous jaws of lingcod and cabezon.  Larger individuals may avoid these ferocious beasts, but must contend with marauding sea lions and harbor seals.  Tiny copepods and other zooplankton that venture into the kelp forest face an imposing gauntlet of filter-feeding appendages belonging to a menagerie of animals that specialize in grabbing microscopic morsels.  Some feasts take place on a far slower time schedule.  Nudibranchs and grazing snails may spend days on a sponge or tunicate, patiently rasping away at their ever-shrinking host.  Sea stars, particularly voracious plodders like sunflower and giant-spined stars, methodically cruise the kelp forest reefs in slow-motion searches for prey.  

     By mid summer, the kelp canopy is at its zenith, fueled by nutrient-rich water and sunlight.  The nearly impenetrable surface mats create a dim underworld beneath the surface, even on those days when sunlight wins the battle against persistent coastal fog.  The cool waters of the California Current, which hug the coast after arriving from the north, ensure that kelp forest waters rarely exceed 55 degrees F, even during spring and summer months.  Phytoplankton blooms frequently reduce visibility to less than ten feet, much to the dismay of divers and other visually oriented kelp forest dwellers.  The resulting profusion of life is certainly well worth any inconvenience to human visitors.  Warmer oceanic water breaks the grip of the California Current a bit during the fall, when phytoplankton blooms tend to diminish and clear water prevails. 

     All this hard effort by giant kelp to conquer the water column seems for naught as the year comes to a close.  Winter storms can wreak havoc in a kelp forest.  Huge swells dislodge kelp holdfasts from their footholds.  Weakened fronds break free, reducing the canopy to a mere skeleton of its summer appearance.  Relentless surge pounds sessile invertebrate colonies that may have spent years trying to blanket several square inches on a rock wall.  Shifting sand covers anemones and other low-lying attached animals.  It might seem to be the worst time to contemplate visiting a kelp forest.  Come between storms however, when seas are glassy calm, and you will see the forest in its most impressive glory.  Lacking the nutrients that bath sanctuary waters during the spring, winter months actually bring the best water clarity of the year.  Combined with the sunny skies that predominate during these generally fog-free periods, winter visibility enables undersea visitors to experience the kelp forest in its ideal splendor. 

     As is usual in nature, when one loses another gains.  Holdfasts that shed their tenuous grasp open territory for multitudes of colonizers whose tiny larvae wait patiently in the surrounding waters.  Bare space is a precious commodity that does not linger.  Deposed kelp in turn serves useful functions throughout the sanctuary, from shorelines to the deep sea.  Tangled, stinking mats appear to mar beaches, but in reality provide shelter and food for kelp flies, amphipods, birds and other opportunists.  Within the kelp forest, snails, bat stars, crabs and isopods munch the toppled fronds.  More adventuresome dislodged plants venture into the open waters of the sanctuary.  Here the floating fronds create oases of shelter in this otherwise vast, barren habitat.  Even the deep-sea benefits.  Kelp that is not decomposed or eaten elsewhere may find its way into the depths of Monterey Canyon, transporting precious organic matter to denizens of the canyon slopes.

     Day by day, the drama of life and death cycles without end in the kelp forest, largely unseen by the eyes of humans.  

Cabezon - Scorpaenichthys marmoratus (Family Cottidae)
Crevice Kelpfish - Gibbonsia montereyensis (Family Clinidae)
Coralline Sculpin - Artedius corallinus (Family Cottidae)
Mosshead Warbonnet - Chirolophis nugator (Family Stichaeidae)
Snubnose Sculpin - Orthonopias triacis (Family Cottidae)
Senorita - Oxyjulis californica (Family Labridae)
Lingcod - Ophiodon elongatus (Family Hexagrammidae)
Longfin Sculpin - Jordania zonope (Family Cottidae)
Wolf Eel - Anarrhichthys ocellatus (Family Anarhichadidae)
Sarcastic Fringehead - Neoclimus blanchardi (Family Clinidae)
Ocean Sunfish - Mola mola (Family Molidae)
KelpPipefish - Syngnathus californiensis (Family Syngnathidae)
Sheephead - Semicossyphus pulcher (Family Labridae)
Kelp Rockfish - Sebastes atrovirens (Family Scorpaenidae)
Painted Greenling - Oxylebius pictus (Family Hexagrammidae)
Gopher Rockfish - Sebastes carnatus (Family Scorpaenidae)
Yellowfin Fringehead - Neoclinus stephensae (Family Clinidae)

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