Wetlands of the California Central Coast
Habitats worth protecting with National Marine Sanctuary Designation
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")
Introduction
"Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season." EPA, America's Wetlands: Our Vital Link Between Land and Water
Wetlands are the most biologically productive of any habitat. They are critical to the survival of local and regional ecosystems because of the diversity of species they support. Coastal wetlands form a vital link between land and sea, exporting nutrients and organic material to ocean waters.
Wetlands not only provide critical habitat for various life-cycle stages of many plants, fish, shellfish, birds and other wildlife, but also provide protection of resources from storm and wave damage and improve water quality by filtering pollutants from sewage outfalls and agricultural runoff.
Coastal wetlands include all wetlands in coastal watersheds — areas of lands from which water drains directly to the ocean — an estuary or bay. There are many types of coastal wetlands: estuarine salt marshes, freshwater marshes, riparian wetlands, bogs, and vernal pools. This article will focus on estuaries.
Estuaries — Where Rivers Meet the Sea
Watch the video below, What is an Estuary?, and learn why these vital waterways of life, culture and economic growth should be protected and restored.
Produced by the Association of National Estuary Programs
Coastal wetlands most common and highly valued in California are estuarine salt marshes with associated tidal channels and mudflats. Estuaries are formed where freshwater streams meet the sea, and contain variably brackish (semi-salty) water that provides a unique mixture of aquatic, semi aquatic, and terrestrial habitats. Typical habitats include salt marshes dominated by pickleweed and eelgrass, mudflats where bivalve mollusks and polychaete marine worms bury themselves, and deeper water tidal channels that provide fish nurseries.
Morro Bay Estuary
Sweet Springs, Los Osos Wetlands
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One of the most significant wetland habitats in California is the Morro Bay Estuary. This estuary is mainly fed by Chorro, Los Osos, and Walters Creeks and is protected from the Pacific Ocean by a long sandspit. Its large areas of eelgrass beds provide critical foraging grounds for thousands of migratory waterfowl of the Pacific Flyway each year. In the Audubon's winter bird count, Morro Bay is consistently one of the top five regions in the country for avian species diversity.
The Morro Bay National Estuary Program (MBNEP) works to protect, restore, and enhance this vital resource to improve our quality of life. MBNEP uses a watershed approach to water and wetlands protection that includes not only the water resource, but also the surrounding land from which the water drains.
The identified priority problems in this 48,000-acre Morro Bay watershed include: rapid sedimentation, increased bacterial and nutrient concentration, freshwater flow reductions, increased heavy metal concentrations and habitat loss, as reported to the EPA "Adopt Your Watershed."
San Luis Obispo Science and Ecosystem Alliance (SLOSEA) brings Cal Poly University students and professors to conduct hands-on problem solving and scientific study of water quality in Morro Bay Estuary. SLO Sea Initiatives
The 2011 review of the MBNEP offers complete information and photos of the ongoing work and successes of estuary restoration.
San Luis Creek
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Oso Flaco Lake
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Besides the Morro Bay Estuary, other important California coastal wetland habitats are the Pismo Dune Marsh located along Highway One to Oceano, the Dune Lakes between Arroyo Grande Creek and Oso Flacko Lake, Oso Flaco Lakes, Santa Maria River Mouth, the Santa Ynez River Estuary and many smaller streams along the coast line such as Santa Rosa Creek, Vila Creek, Morro Creek, San Luis Creek, Pismo Creek, Arroyo Grande Creek and Jalama Creek.
Wetlands Aquatic and Terrestrial Features
Coastal Wetlands are biologically productive habitats supporting both aquatic and terrestrial species. Over many years, plants and animals that inhabit wetlands have successfully evolved morphological (form and structure) and physiological (normal functions) adaptations to the presence of high levels of salt and periodic drying out as well as low concentrations of dissolved oxygen in the waterlogged soils and exposure to alternating fresh and salt water.
Salt marsh food webs are the most complex in nature. Ecologists have estimated that a healthy salt marsh produces from five to ten times as much oxygen and corresponding carbohydrate biomass per acre as a wheat field. Marsh plants capture the energy of sunlight and, through the process of photosynthesis, convert it to carbohydrates that provide food for the complex wetlands food web.
A key part of each food chain and the wetlands success begins with the breakdown of plant matter into detritus (smaller organic material), which is then consumed by filter feeders, deposit feeders and other omnivores and scavengers. Decomposers, such as bacteria and fungi, also break down plant and animal matters and recycle the nutrients. This assemblage of producers and consumers creates a large food web, with fish, birds and humans as the ultimate links.
Morro Bay Wetlands
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Wetlands Survival
California has lost over 90% of its historical wetlands and heavily polluted other important estuarine areas from human activity. When cities are built near wetlands, threats to estuaries may include landfill, diking, dredging, and pollution.
Thus, the remaining wetlands are of great importance to the food chain and habitat niche. Wetlands are critical to the survival of local and regional ecosystems because of the diversity of species that they support.
Coastal wetlands provide a home to a variety of animals, numerous fish species, insects, and birds. Coastal California is part of the Pacific Flyway, one of the four principal bird migration routes in North America. During the spring and fall months, coastal wetlands support flocks of waterfowl, shorebirds, and others that stop in the wetlands to rest, feed, and in some cases overwinter.
Fresh water and storm water enters a wetland from rivers and streams flowing to reach wetlands, exporting pollutants picked up along the way to both the wetlands and the ocean waters.
"Think Blue Main" is a creative video using rubber duckies to show how pollution enters our waters.
Wetlands of the California Central Coast are habitats worth protecting with National Marine Sanctuary designation. Many groups are contributing to the scientific study and protection of our estuaries.
For further information:
Central Coast Salmon Enhancement – Enhancing Fisheries While Improving the Environment
The Central Coast Wetlands Group (CCWG) - works to improve the condition of our local wetlands.
California Coastral Resource Guide, by California Coastal Commission, Madge Caughman, Joanne S. Ginsberg, ISBN: 9780520061866, November 1987
