by Greg Karpain
The Gaviota Coast spans 76 miles and some 200,000 acres located in western Santa Barbara County between Coal Oil Point and Point Sal. Its southern portion lies between the Channel Islands National Marine Sanctuary and the Los Padres National Forest. For reference, the Gaviota Coast Conservancy’s (GCC) area of active interest and stewardship is marked by the solid red line as seen on our website at:
https://storymaps.arcgis.com/stories/2ace08fd24b04e36a3f0956c385f4b1e.)
The Gaviota Coast encompasses many coastal watersheds of the Santa Ynez Mountains. Where these watersheds eventually join the ocean, marine and terrestrial bio-geographic boundaries merge along the Gaviota Coast to create safe harbors for many rare and endangered species. These meeting and merging places are called estuaries and are unique because they are a major ecotone on the coast. Generally, an estuary is where a creek or river empties into the ocean, the river mouth. An ecotone is defined as a transition area between two biological communities, where two communities meet and integrate. In the case of the Gaviota Coast estuaries, the marine ecosystem and the riparian stream ecosystems are the two ecotones that meet and mingle, much to the delight of the many species that call these estuaries home, either permanently or as a stop along their migratory travels.
Estuaries and Salt Marshes: Kissing Cousins
A salt marsh (or salt wetland) is basically part of an estuary. Not every estuary harbors a salt marsh. For example, a creek or river estuary could conceivably spread out into a nice freshwater estuary on a coastal plain above the ocean, creating a wetland in a flat area, and then fall into the sea from above. This difference in elevation would prevent the sea from mingling with the freshwater wetlands above. However, for this blog, we are going to be discussing only areas where the stream and the ocean do intermingle. Freshwater streams rush down the steep slopes of the Santa Ynez Mountains toward the ocean, creating a number of estuaries with salt marsh habitats. They share the mixing of the salty marine and freshwater environment in common. A salt marsh is a wetland area found near estuaries and sounds. The water in salt marshes varies from completely saturated with salt to mainly freshwater with only light saltwater mixing. Estuaries are partly sheltered areas found near river mouths where freshwater mixes with seawater. In general, if a river or creek estuary rushes straight into the ocean, as many of the creeks in the Gaviota Coast watershed do, there is a minimal mixing of marine and freshwater environments. It is more of a “river mouth” than a salt marsh. However, where the geography, dunes, flatness of the estuary, etc. allow, a salt marsh may have formed over the ages.
The size and power of high and low ocean tides determines much of the character of how the two ecotones intermingle. Some areas of the world, for example, the bay of Fundy in eastern Canada https://bayoffundytourism.com/worlds-highest-tides/. Twice each day, 160 billion tons of seawater flow in and out of the Bay of Fundy, more than the combined flow of the world’s freshwater rivers! The Bay of Fundy’s tides transform the shorelines, tidal flats and exposed sea bottom as they flood into the bay and its harbors and estuaries. We don’t find anything that dramatic on the Gaviota Coast. Anyone who visits our local beaches is familiar with average range of the lowest and highest ocean tides. I’ve seen a coastal salt marsh almost completely “drained” at low tide and have seen the same marsh fill up and look like a lake, with little land showing at a high king tide. And that means that means that whatever flora and fauna is in the salt marsh, is flooded with salt water.
These intertidal habitats are essential for healthy fisheries, coastlines, and communities—and they are an integral part of our economy and culture. They also provide essential food, refuge, or nursery habitat for more than 75 percent of fisheries species, including shrimp, blue crab, and many finfish.
Although the Gaviota Coast has several estuaries where the ocean and riparian freshwater ecotones mix, it doesn’t have any really large salt marshes. However, many examples of large California salt marshes are found to the north and to the south of the Gaviota Coast. Up north we find many well-developed examples of northern coastal salt marsh communities. This plant and animal community occurs along the California coast from Oregon to near Point Conception where it intergrades with southern coastal salt marsh. It is especially extensive around San Francisco Bay but is also well developed at Humboldt Bay, Tomales Bay, Elkhorn Slough, and Morro Bay.
Some wonderful examples of larger salt marshes that we have locally (just past the southern border of the Gaviota Coast) are the Devereux Slough, the Goleta Slough, and the Carpinteria Salt Marsh. The actual boundary lines defining the Gaviota Coast are actually pragmatic and imaginary lines, and I would be hard-pressed to divorce the Devereux Slough and Carpinteria Salt marsh from the Gaviota Coast ecosystem just because it has a different zip code.
Salt Marshes
A salt marsh, often called a salt wetland, is a coastal ecosystem in the upper coastal intertidal between land and the open ocean. A key defining factor is that a salt marsh is regularly flooded by the tides, often taking on the appearance of a shallow lake. It is dominated by dense stands of salt-tolerant plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh in trapping and binding sediments. Plant species in salt marshes are adapted to high salinity conditions with various unique adaptations, including the ability to expel salt from the plant (Saltgrass, Distichlis spicata), sequester salt in tips of stems (Pickleweed, Salicornia virginica), and reduce water loss through succulent stems, reduced waxy and grey leaves. Salt marshes play a large role in the aquatic food web and in the delivery of nutrients to coastal waters. They also support terrestrial animals and can protect the coast from erosion.
A few salty wetlands worth mentioning on the Gaviota Coast are:
- Santa Ynez river mouth estuary (Vandenberg Space Force Base)
- Gaviota Creek estuary (Gaviota State Park)
- Refugio Creek (Refugio State Park)
- Dos Pueblos Creek (Dos Pueblos Ranch)
- El Capitan Creek (El Capitan State Park)
And south of the Gaviota Coast:
- Devereux Slough (Coal Oil Point Goleta)
- Goleta Slough (Goleta Beach / Santa Barbara Airport area)
- Carpinteria Salt Marsh (Carpinteria)
Restoration Efforts
Most of the Gaviota Coast estuaries could use a good restoration. Human influence along California’s coastline has a long history. The effect of this history is evidenced by the profound alteration of the natural environment, most pronounced of which are the modification and loss of the shallow-water / wetland habitats within the state’s bays and estuaries and the staggering loss of coastal wetlands. The total loss of California coastal wetlands is estimated at five million acres! This represents some 91 percent of the historic wetland acreage present before 1850. Although the entire coastline of the state has experienced losses of coastal wetland habitat, the largest losses are believed to have occurred in the San Francisco Bay estuary and along the southern coast of the state. Southern California once had over 53,000 acres of coastal wetland areas. This number is now down to approximately 13,000 acres. Fortunately, the tide has turned, pun intended, and tidal wetland protection and restoration activities have become front-page news in many areas of the state and funding sources, once unobtainable, are now becoming increasingly available. Due to the hard work of all environmentalists, wetlands are now recognized as them, and as aesthetic, functional, and most importantly, environmentally necessary elements in the interconnected web of life. California’s remaining coastal wetlands are highly valued as habitat for the multitude of species that depend on them.
The Gaviota Coast Conservancy has been supporting the Coastal Ranches Conservancy over the last three years in the complex struggle to restore the Gaviota Creek estuary to its natural state. This estuary, as well as others along the Gaviota Coast are important nursery areas for salt water and anadromous fish, like the Southern Steelhead and Tidewater Goby, as well as providing valuable habitat for birds. Also, they are all threatened by sea level rise unless the parking lots and other impediments are removed to allow the natural hydrological processes to proceed to restore and shape the estuary.
In fact, a wonderful example of the biodiversity (that GCC is always on the lookout to protect) can be found in the seven species of fish which live in the Gaviota Creek estuary in Gaviota State Park. Today, this estuary is only 1.9 acres in size, although it used to be approximately 11 acres before it was filled in over the years. And yet all these different species of fish can still be found here:
- Southern California Steelhead-endangered
- Arroyo Chub- rare species of concern
- Tidewater Goby- endangered
- Three-spine Stickleback
- Staghorn Sculpin
- Prickly Sculpin
- Topsmelt
Gaviota creek estuary has the endangered Tidewater goby and the endangered Red legged frog resides further up the estuary, even despite the fact that it is partially filed in to form the Gaviota beach parking lot. We still hope to help steward a complete restoration of the Gaviota Creek estuary to its former glory by removing areas of fill. The fish are standing by.
In fact, a wonderful example of the biodiversity (that GCC is always on the lookout to protect) can be found in the seven species of fish which live in the Gaviota Creek estuary in Gaviota State Park. Today, this estuary is only 1.9 acres in size, although it used to be approximately 11 acres before it was filled in over the years. And yet all these different species of fish can still be found here:
- Southern California Steelhead-endangered
- Arroyo Chub- rare species of concern
- Tidewater Goby- endangered
- Three-spine Stickleback
- Staghorn Sculpin
- Prickly Sculpin
- Topsmelt
Gaviota creek estuary has the endangered Tidewater goby and the endangered Red legged frog resides further up the estuary, even despite the fact that it is partially filed in to form the Gaviota beach parking lot. We still hope to help steward a complete restoration of the Gaviota Creek estuary to its former glory by removing areas of fill. The fish are standing by.
Other Local estuaries and marshes south of the Gaviota Coast
Carpinteria Salt Marsh : https://carpinteria.ucnrs.org/
The Carpinteria Salt Marsh Reserve protects a critically important Southern California estuary which supports many sensitive plant and animal species. The site includes extensive wetland and channel habitats along with some uplands. It lies adjacent to a sandy beach, subtidal rocky reef, and kelp beds. The reserve provides habitat for migratory waterfowl as well as endangered plants and animals such as the salt marsh bird’s-beak, light-footed clapper rail, and Belding’s savannah sparrow. The Marsh serves as an important regional nursery for halibut and other marine and estuarine fish.
The marsh is now a busy, healthy ecosystem filled with rare birds, fish, snails, sharks and plants. Nestled between homes, agriculture, nurseries, the railroad and freeway, the marsh is one of the last remaining coastal estuaries in California. Less than 10% of the historic wetland habitat exists in California, and this 230-acre reserve is one of the only places left where the land meets the ocean, providing an essential environment for numerous plants and wildlife.
Carpinteria Salt Marsh was once part of the much larger El Estero wetland that is now largely occupied by the city of Carpinteria. UC Natural Reserve System founder Kenneth Norris identified Carpinteria Salt Marsh as a priority for the nascent NRS in 1966.Through a combination of gifts and purchases the University of California acquired the center portion of the marsh and established the Carpinteria Salt Marsh Reserve in 1977.
Coal Oil Point/Devereux Slough: https://copr.nrs.ucsb.edu/
Coal Oil Point Reserve is part of the University of California Natural Reserve System. The reserve protects natural habitats to support research, education, outreach, and stewardship.
One of the best remaining examples of a coastal-strand environment in Southern California, the Coal Oil Point Natural Reserve protects a wide variety of coastal and estuarine habitats. Largely undisturbed coastal dunes support a rich assemblage of dune vegetation and rare wildlife, including the dune spider, the globose dune beetle and the threatened Western Snowy Plover.
In the heart of the reserve, Devereux Slough is a seasonally flooded tidal lagoon that dries out in the summer to form salt flats and hypersaline ponds, and channels. A variety of intertidal habitats occur along the sandy beach and the large rocky reef at the point. Thousands of migratory birds visit throughout the year. Coal Oil Point Reserve is part of Audubon’s Important Bird Area (IBA) and it is visited daily by birders. Previous studies observed how this estuary changes seasonally. We have a lot more to learn about how changes in Devereux Slough affect the flora and fauna of the reserve.
The grassland and coastal scrub mix have patches of disturbed and undisturbed areas and offer opportunities for experiments in restoration. Vernal pools host a number of rare and endemic species. At low tide, the intertidal and subtidal zones at the reserve provide an opportunity to observe the rich assemblage of invertebrates and algae living on the rock formations.
Located less than 3 miles from the UC Santa Barbara campus, the reserve provides a unique and accessible research and teaching resource. A Nature Center is now open to better serve the students, researchers, and community.
