Kelp Forest Ecosystems
Ocean Habitat Feature of Local, National, and International Significance
by Carol Georgi and Karl Kempton
former Energy Planner for San Luis Obispo County
and Lead Author of "Proposed Central Coast National Marine Sanctuary, 1990"
Sea Otter Atop Kelp Forest
Photo by Carol Georgi
Introduction
Have you ever wondered what lives under the kelp floating in our California nearshore waters?
Kelp Forest Ecosystems are the richest ocean habitat, that provide filtering of water, fish nurseries, food, biodiversity, and tourism. They are underwater treasures needing protection from pollution and destruction for their survival.
Watch a sample of this video to enjoy a mind-expanding view of the underwater world along the California Central Coast.The kelp forest ecosystem is one of the most diverse places in the world and one of the least explored, known or understood.This DVD shows many ocean creatures, including: giant lingcod, huge schools of rockfish, rare angel sharks, colorful sea slugs and anemones in every color of the rainbow, 300 pound seals, giant crabs and lobsters.
Terry Lilley and Sue Sloan explore the undersea world of the kelp forests off California's Central Coast, filming a world of surprising beauty, color and diversity. Diving over 1000 times from kayaks, Lilley (marine biologist and former pro-surfer) and his assistant Sloan introduce us to the rich marine life of the kelp ecosystem. Watching this film, we easily see why these ecosystems, rarely found in Southern California, need to be protected, especially by a national marine sanctuary.Come with Terry Lilley and Sue Sloan as they descend into the world of the kelp forest off California's Central Coast.
Video and Narration by Biologist Terry Lilley and Assistant Sue Sloan
"Lilley and Sloan have documented the amazing richness of life just under the waves off California's Central Coast--known to some marine biologists and described in dry dissertations, but unguessed at and unseen by most. Lilley and Sloan have made it real, giving us all a great gift and making clear the need to preserve and protect this treasure."Andrew Christie, Director, Santa Lucia Chapter, Sierra Club.
You can order a Kelp Forest DVD from SLO Surfrider Foundation, PO Box 13222, San Luis Obispo, CA 93406. Please include a check made out to SLO Surfrider for $20, shipping is included.
Kelp Forest Ecosystems
The kelp forest ecosystems includes invertebrates, fish, marine mammals, birds, plants, and more. "An ecosystem is an ecological community comprised of biological, physical, and chemical components, considered as a unit. Coastal ecosystem science is the study of inter-relationships among the living organisms, physical features, bio-chemical processes, natural phenomena, and human activities in coastal ecological communities."
Given the scale of the sum total of the global coastlines, kelp forests are not that common. Considered the rain forests of the ocean, kelp forests are found along the coasts of Argentina, through the Straits of Magellan to Chile, off South Africa, Australia, New Zealand, and many sub-Antarctic islands, and from central Baja California to Sitka, Alaska. The most developed of all these kelp forests are found off of the California coast, from San Diego to Santa Cruz and the islands west of Southern California, especially the Channel Islands within the Channel Islands National Marine Sanctuary.
Increasing human populations pose threats to the survival of the kelp forests. According to a study by Lauretta Burke, Yumiko Kura, Ken Kassem, Carmen Revenga, Mark Spalding, and Don McAllister at the World Resources Institute, "As coastal and inland populations continue to grow, their impacts — in terms of pollutant loads and the development and conversion of coastal habitats — can be expected to grow as well. Nutrient pollution has increased dramatically this century due to greater use of fertilizers, growth in quantities of domestic and industrial sewage, and increased aquaculture, which releases considerable amounts of waste directly into the water. Increasing fishing pressures have left many major fish stocks depleted or in decline."
Sea Star |
Rock Fish |
Sunlight in Kelp Forest |
Sea Star, Sea Anemone, Sponge
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 Sunflower Star
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General Features
While we see only the top of the kelp forest floating on the water's surface, kelp canopies can reach depths of 200 feet. Different types of kelp and algae form under-stories which provide numerous benthic (bottom communities), mid-water, and surface habitats, nursery areas, protective covers, and food items important for invertebrates, fishes, and sea mammals.
Seabirds roost and maintain rookeries on large exposed rocks close by or within the forests. Several endangered marine mammals, sea otters, northern elephant seals, harbor seals, and sea lions inhabit these areas and haul out on the rocks. Gray and humpback whales feed nearshore. Approximately 300 algae species are present. Rocky intertidal coastal marine habitats host an assortment of invertebrates and fish. Species such as blue rockfish and abalone use cracks and crevices for protection against predators and for breeding.
Much of the California Central Coastline is dominated by rocky intertidal zones lush with large and significant kelp forests. Kelp generally requires rocky hard-bottom for attachment and growth, but physical factors such as light availability and amount and type of rocky substrata affect the range of each species. In this environment, kelp — fed by the rich nutrient broth carried by upwellings (constant and seasonal) and their associated currents — can grow 10 inches or more a day, forming a lush underwater habitat.
Internationally Significant Persistent Upwelling
A major oceanographic feature of international significance, and perhaps the most important marine food source, is the persistent and constant upwelling which brings up rich nutrients between Point Conception and Point Sal through the underwater Arguello Canyon. This is the only persistent upwelling along the entire U.S. West Coast. The California coastal waters are also fortunate to have strong seasonal upwellings along the coast feeding these rich and diverse habitats. The kelp beds along the rocky intertidal zones are among the richest kelp habitats in the world. The upwellings feed this great treasure.
Stressors to the Kelp Forest Ecosystems
The kelp forests are under stress due to a number of causes. Among them are urban runoff, pollution, petroleum processing waters discharge, sewer water discharge, agriculture runoff, and once through cooling at power plants. Some kelp forests disappeared for a number of years before regrowing. Others are greatly stressed by an over abundance of kelp-grazing sea urchins that no longer are threatened by predators, such as the important kelp bed protector, the sea otter.
The Southern California Bight is the coastal region extending from Point Conception in Southern California to Cabo Colonett and Bahia de San Quintin in Baja California. Municipal waste outfalls are the worst source of pollution and outweigh all other sources. (Darwin) Even the Channel Islands kelp forests are impacted by pollution carried by the Southern California Bight Circulation System.
Such stress and impacts on these kelp forests greatly increases the international importance of preserving the unprotected kelp forests between Point Conception and Santa Rosa Creek. Expansion of either or both the Channel Islands National Marine Sanctuary and the Monterey Bay National Marine Sanctuary would add needed research and sustainable protection. Meanwhile, we can learn from marine sanctuaries how to restore, protect, and appreciate our coastal ecosystems in San Luis Obispo County.
According to the National Oceanic and Atmospheric Administration, (NOAA), "National Marine Sanctuaries are unique places addressing key issues facing our world — one special place at a time. Marine sanctuaries are helping to create a new paradigm, one that encourages a change in behavior. A lifestyle that sustains our planet, rather than using our planet to sustain our lifestyle. These special places not only offer beauty and inspire wonder, but also provide solutions to the challenges facing the ocean, the planet, and us. By working together, Marine Sanctuaries connect communities while working on solutions to complex problems. Now, more than ever, the protection of sanctuaries is critical to the health of fragile ecosystems."
Despite over fifty years of research, the complex dynamics of California kelp forests are not fully understood. The least understood dynamic is that of the nutrient cycle associated with nutrient-rich upwelling waters, seasonal or persistent. The food web is another dynamic needing greater study. Thirdly, the dynamic of kelp forest health and its foragers, the kelp eaters, and their predators is not fully understood. Lastly, winter storms break off the top canopy of the forests, carrying kelp either to the beach or into deeper waters. Exported kelp, slowly moving across the bottom into deeper zones, creates rich habitat for a variety of life forms not yet thoroughly investigated. Ecosystem effects of the drift exceed that of a terrestrial forest because of uses for the kelp far beyond the forest. Marine Sanctuary protection status would set the stage for needed research efforts. For more detailed information, see Chapter 8 Diversity and Dynamics of California Subtidal Kelp Forests by M. Graham.
California Central Coast Kelp Forest from Point Conception to Santa Rosa Creek
Much of the unprotected rocky intertidal nearshore coastal marine habitats from Point Conception to Santa Rosa Creek in Cambria are dominated by kelp forest. The kelp forest is not continuous, as it is broken by long stretches of sandy bottom between Point Arguello and Pismo Beach and north of Hazard Canyon to Cayucos. There is a long kelp forest area from south of Point Conception to Point Arguello. The area hosts great densities and diversities of flora and fauna. The southern zone of Point Sal hosts a small kelp forest. The densest and longest stretches are found between Point San Luis and Hazard Canyon along the Pecho coast and from Cayucos Creek to Santa Rosa Creek.
Pismo Beach to Northern San Luis Bay
The rocky intertidal area of northern San Luis Bay begins at the northernmost end of the 26 miles stretch of sandy beach of Pismo Beach. From this rocky cliff area along the coastline to the southern end of Avila Beach, another high rocky cliff, a major kelp forest flourishes beyond the 200 foot depth bathymetric line (a depth contour line on the chart). The coastline varies from rocky cliffs with no beaches to cliffs with some beach. Despite the beach areas, the dominant rocky hard bottom offshore provides appropriate habitat for the kelp forest and its lush populations of plant and animal life.
The area is host to the southernmost population of sea otters in the sea otter southern range. In 1990 it was ranked as the sixth largest population cluster. Since then, the population has fluctuated up and down. The reason for these fluctuations remain under study. Pollution from onshore is considered the most likely cause or causes. High cliffs, intertidal rocky areas, beaches along the feet of the cliffs, and nutrients from a nearby upwelling provide a rich environment supporting otters, other sea mammals such as porpoises and sea lions, and large numbers of other species in the web of life.
Numerous offshore rocks provide bird and pinniped habitat. Hundreds of Brown Pelicans, for example, reside in the area. Their numbers swell in the late spring, and remain high until late fall when most return to the Channel Islands for breeding. Harbor seals haul out among and on the rocks. A resident population of harbor seals offshore Shell Beach is a source of enjoyment for people living in the area or visiting. Porpoises visit the area often. Gray whales pass southward and northward during their migrations. Giant flocks of Sooty Shearwater birds feed here in the summer during their travels around the Pacific basin. Huge schools of anchovies moving through are a food source for a wide variety of bird and mammal populations.
Pecho Coast
The Pecho Coast marine environment consists of a 13-mile stretch of intertidal rocky reef beginning at Point San Luis and ending at Hazard Canyon to the north. The shoreline is characterized by sheer, wave-eroded cliffs, jutting headlands, and massive offshore submerged and exposed rocks. Above shoreline the narrow coastal bench is flanked by hills. The tidal zone is generally narrow and may terminate abruptly where protection from wave shock is minimal and deposition is reduced or absent. These topographical features form a highly irregular coastline. The coast provides many different exposed and protected habitats which extend or control the abundance and composition of marine plants and animals.
Long sandy stretches of coastline are found north and south of the reef. The reef supports important communities of vertebrates and invertebrates each integrally dependent upon each other and upon dense stands of canopy formed of kelp and lower growing algae. Damage to or extermination of reef fauna would result in a extremely slow recovery due to the reef's isolation from other rocky coastal habitats and the non-migratory behavior of indigenous species.
Because of the combination of rocky intertidal zone, a seasonal upwelling off Point Buchon, large offshore rocks, kelp beds, climatic and oceanographic province transition zone, and lack of direct human interference, the area between Hazard Canyon and Point San Luis remains a lush floral and faunal habitat. The area supports a significant and growing population of breeding female sea otters, a large breeding population of sea lions which haul out at Lion Rock, a population of elephant seals which haul out on the mainland, a community of harbor seals, and a large number of seabird species populations.
Waters within the area are considered pristine not only due to the abundance of life as indicators, but also because of the presence of Allopora Coral, an hydrocoral. This hydrocoral, a tree-like form usually found in waters 50 meters deep, has been discovered near Lion Rock in waters only 15 meters in depth.
Diablo Cove and Diablo Nuclear Power Plant (DNPP) use of Once Through Cooling (OTC)
Diablo Cove has been one of the primary focal points for intertidal research in the proposed sanctuary area. Financed by PG&E, numerous investigations have resulted in descriptions of an abundance of flora and fauna. Among a host of important finds, research shows the area to be an important nursery for both rocky reef and deep water fish. The research supports conclusions that the San Luis Obispo (SLO) County coastline supports one of the richest intertidal rocky reef fisheries in the world. This research, however, neglected to make public the continued extensive damage the OTC system of the DCNPP does to marine life.
Diablo's OTC system draws daily about 2.5 billion gallons of seawater with marine life from roughly 93 square miles of ocean. This daily cooling process kills about 1.5 billion eggs and fish larvae each year. Having begun in May 1985, Diablo's OTC system continues to cause marine life destruction in three main ways. (See: Slo Coast Journal.com - Marine_Sanctuary)
1.Impingement- The killing of larger organisms such as fish, shrimp, crabs, jellyfish, and sea turtles by pinning them against screens covering the intake when the strong suction of seawater with marine life are brought into the OTC system.
2.Entrainment- The killing of small marine life such as fish larvae and eggs when they are sucked into and drawn through the OTC system with the water. They die by combined effects of temperature, pressure, biocide residual, and turbulence and then are expelled back to the aquatic environment in the effluent. The estimate for DNPP is more than 1.5 billion larvae each year. (Diablo Canyon and PG&E Deal)
3.Thermal effects."Cooling water is typically 20 degrees warmer when it is discharged from Diablo Canyon’s cooling system. This influx of warm water alters the ecosystem of the discharge cove. Kelp, other forms of algae and small fish, particularly in the shallow areas along the shore of the cove, are the most heavily impacted." (Diablo Canyon and PG&E Deal and Diablo canyon and PG&3 Deal 2)
Diablo's OTC system impacts fish larvae 47 miles along the shore and in nearshore waters as far as two miles out. The kelp forest along the Pecho Coast is of great significance as well as the inner waters of the adjacent Morro Bay National Estuary waters where the now rare eel grass provides shelter for fish nurseries. The direct and indirect destruction reaches far. The (SLO) County coast line is about 109 miles in length. This means almost half our SLO County nearshore waters are negatively impacted by PG&E's nuclear power plant. (See Slo Coast Journal - November 2010)
Cayucos Pier to Santa Rosa Creek and Ocean Rose Abalone Farm
The northern kelp forests begin on the north side of the Cayucos pier, along the coastline passed Point Estero to Santa Rosa Creek, arcs outward beyond the two hundred foot depth bathymetric line and southward back to the north side of the pier. Santa Rosa Creek is the southern boundary of the Monterey Bay National Marine Sanctuary. This section of the coastline, with low lying benches rising to small coastal hills, contains jagged rocky coastline and offshore reef. Facing southward and protected by the hills, a portion of the area north of Cayucos is protected from prevailing northwest currents, winds, and harsh storms. Numerous small coves are found along the coastline.
Comprised of rocky intertidal zones associated with dense kelp forests and other algae populations, the area supports a wide diversity of life. One of the largest sea otter population clusters resides within this zone. Offshore rocks provide rookeries and roosting sites for birds and haulouts for pinnipeds. 500 to 600 harbor seals are found here. Whales other than gray whales occasionally visit within this zone. Gray whales stack at Point Estero during migrations.
Between Villa Creek and Point Estero is a commercial abalone farm that was established in 1968. It ships abalone to various national and international customers. From its web site: "The Abalone Farm is a proud participant in the Monterey Bay Aquarium's Seafood Watch program." The Abalone Farm maintains a kelp harvester, the 56-foot Ocean Rose, that cuts and collects kelp to feed to their growing abalone farm. The harvester has an 18-ton hold which can often be filled by noon. However, endangered sea otters live in kelp, and local residents have questioned the activity of the Ocean Rose harvester coming with a few feet of and endangering the sea otters in the kelp. The California Department of Fish and Game provides permits and guidelines for kelp harvesting.
Conclusion
The pristine kelp forest ecosystems along the nearshore of the California Central Coast between the Channel Islands National Marine Sanctuary and the Monterey Bay National Marine Sanctuary are both ecologically and economically highly valued by the marine environment and the human population. Preserving the sustainability of these kelp forests needs to be a top priority of every coastal economy. The human population needs to change their paradigm of throwing waste into the ocean. Beginning with picking up dog waste to eliminating the wastewater outfall from wastewater plants, we need to change for both our health and that of the ocean. For more information on water usage and to watch "The Cycle of Insanity" from the Surfrider Foundation, see Slo Coast Journal - February 2011.
