Hidden Wonders

You’ve probably passed the Carpinteria Salt Marsh while driving along the glorious section of the 101 Freeway between Ventura and Santa Barbara. You may have glanced oceanward and noted railroad tracks fronting the flat wetlands of the marsh.

At first glimpse, the flat terrain with stubby plantings and little variation in color seems a gloomy wasteland, a shabby second cousin to gleaming sand beaches where tide pools vibrate with life, and ocean waves splash and foam.

But get inside and the marsh works its magic, becoming ever more beautiful as closer investigation reveals its complexity and diversity.

Before a visit to the marsh, I reviewed my collection of books about California terrain to recall that a marsh, like a bog or a swamp, is one of the Earth’s soggy zones, the low places periodically or seasonally moist or flooded with water. Marshes develop in lowlands such as flood plains and muddy deltas of rivers and creeks where drainage is poor.

Salt marshes are unusual because they form along the ocean coastline, frequently near shallow lagoons, particularly those sheltered by sandbars or barrier islands. The vegetation in sea-saltwater marshes is regularly flooded by ocean water surging in and out twice a day and by fresh water flowing into the sea from mountain rivers and creeks.

Because of the delicate balance between tidal salt water and nutrient-rich fresh water, salt marshes are among the most productive habitats in the world and support a large variety of animal and plant life. They serve as breeding grounds for waterfowl, fish and other wildlife. For some endangered species, such as the salt marsh bird’s beak plant and the light-footed clapper rail, the marsh is the last stronghold.

The Carpinteria Salt Marsh has garnered much attention for the past 20 years as one of the few estuaries that remain in Southern California.

Cooperation among concerned citizens, city and county agencies, trusts and University of California scientists has not only preserved the marsh but enhanced it.

The marsh is accessible to the public, thanks to a restoration project that includes the Carpinteria Marsh Park, a city park with marsh access and interpretive programs.

Upon arriving at the marsh, our small group was met by Wayne Ferren, manager of the marsh reserve and associate director of the UCSB Natural Reserve System.

Ferren, who also is executive director of the UC Santa Barbara Museum of Systematics and Ecology, gave us the geologic and political background of the marsh, explaining that it is an estuarine trough covering 230 acres at the base of the Santa Ynez Mountains.

The Santa Ynez mountain range above the foothills feeds the creeks that deposit sediment into the marsh. If it weren’t for channels built in the late 1960s to convey storm runoff to the ocean and reduce the potential for flooding in the city, this sediment would exceed the capacity of the marsh. Construction of a rock retaining wall has helped keep open the mouth of the marsh.

No plants grow in the sloping areas of the marsh where large patches of highly salty mud predominate. And, at first glance, the plants that do grow seem less than spectacular.

Dave Hubbard, an expert on the plants of the marsh, bounded about the terrain like a puppy finally off the leash, bringing these plants to life for the group. Hubbard is part of the Marine Science Institute and the Natural Reserve System at UCSB, where he specializes in endangered plants, among other wetland topics.

He described the variables--frequency of flooding, depth of water, salinity and length of submergence--that determine where plants grew. These plants often have to contend with a salt concentration as high as 10%, due to evaporation of water in the irregularly flooded zones.

Salt-tolerant plants, known as halophytes, don’t absorb much water but have thick, leathery leaves to retain the water they have. Plants at the mud fringes such as glasswort and sea blite can tolerate high salinity because they excrete excess salt from their shoots. Their roots stabilize the mud and allow other plants to become established.

Others, such as sea lavender and narrow-leafed ice plant, are deciduous, shedding excess salt with their leaves. Holding up an ice plant, Hubbard seemed to chastise it while explaining, “This plant sequesters salt in the epidermal cells of the leaves. When it dies, the salt released by rain results in a high-salinity dead zone. Look how there are no plants growing around it.”

Hubbard’s interests include endangered plants such as salt marsh bird’s beak. The bird’s beak is restricted to high marsh habitat where rainfall determines its germination. Its resourcefulness as a root parasite allows it to survive summer heat and drought after most of the other annuals in the high marsh go to seed. Hubbard also pointed out shore grass, arrow weed, jaumea, and the plentiful, and edible, pickleweed.

As we walked toward the ocean on a road left over from past attempts to drill for oil, Andrew Brooks, our expert on marsh-dwelling fishes pointed out a series of pipes rising from the channel waters. These, he said, support the large, cylindrical enclosures used in his studies of two groups of fishes living in the marsh.

In such an environment, fish habitats constantly fluctuate with the tides, with water depth in many channels varying from several centimeters to a meter or more during the course of a day. As the water levels in the channels drop, the temperature of the water increases. Although most of the permanent marsh residents have adapted to living in the sometimes shallow and warm waters, others have not. According to Brooks, these more transient species must wait offshore or in the deeper channels until high tide when the cooler ocean waters refill the shallower channels.

Brooks explained that of the 37 species of fishes found in the Carpinteria Salt Marsh, only four or five, such as the California killifish and a variety of gobies, are permanent members of the marsh’s fish community.

According to Brooks, the remaining 30 or so species include leopard sharks, bat rays and the California halibut, which fall into a second group of fishes using the marsh as a temporary feeding ground or as a nursery.

What do these scientists like showing students in the K-12 education program who visit the marsh?

“I love showing them the marsh channels during incoming tides, especially in summer when sharks and stingrays enter,” said Ferren. “They love watching the sharks that come into the estuary to eat crabs, and the rays that come in to eat clams and to mate.”

Mark Page, another scientist from the Marine Science Institute, shared his insights on the mollusks that thrive in the marsh. He pointed out clams that reflected two styles of feeding. The common little neck clam is a suspension feeder--it filters nutrient-rich algae from the water.

Running a finger over the arched shell, which gives the name to the bent-nosed clam, Page seemed to take an almost parental pride in its skills as he explained that “This one is a deposit feeder that sucks up particles from the mud’s surface like a great vacuum cleaner. If you want to see these crabs and mollusks, the best time to come is low tide.”

As if to prove Page’s point, Ferren waded into the nearby channel, now at low tide, and brought up a clump of mussels, oysters and barnacles. He explained that oyster beds decline when smothered by silt and prolonged exposure to fresh water.

Suddenly, our attention was divided between a long-billed curlew in one direction and an exquisite snowy egret in another.

The marsh is at or near the limit of the northwestern geographic range for many species, including Belding’s savannah sparrow and the light-footed clapper rail. Cormorants, grebes and pelicans can be spotted off the coast. The estuary is important for both resident species, including shorebirds (marbled godwits), wading birds (great blue herons), gulls, terns and passerines (Belding’s savannah sparrows); and for migratory and seasonal use by long-billed curlews, least terns, snowy plovers and other species.

These migratory birds gorge themselves on fish or invertebrates before flying on to South America or the Arctic Circle, depending on the season. During winter migration, as many as 2,000 shorebirds have been recorded at the marsh in a single day.

Bird-watchers come to the marsh in July seeking the clapper rails. These birds are easiest to spot at evening high tide when they perch on the pickleweed-covered sand hillocks, silhouetted by moonlight to the east or the setting sun to the west. Upland areas provide roosting for raptors. Cooper’s and red-tailed hawks, black-shouldered kites and ospreys are also visitors to the marsh.

Currently the marsh is showing some strange signs of health. While the three other scientists recoiled slightly, Ferren held up several dormant horned snails and proudly proclaimed, “These snails are the primary hosts for at least 15 worm parasites, which cause sterility in snails.”

Birds feed on fish, crabs or mollusks, hosts to the free-swimming form of the parasite; then, through bird droppings, deposit the parasite eggs back in the marsh. Thus, the abundant population of worms in the snails reflects the ecosystem’s support of numerous fish, mollusks and birds.

But change is having its impact. This estuary is filling in with sediment after 9,000 years of interaction with humans. This is why the scientists are working to preserve the biologically important ecosystem of the marsh.

Their reasons range from the ecological to the academic to the poetic. As much as anything, they want generations of visitors to be able to enter a seemingly monochromatic flatland and discover, as we did, the vibrant palette of life and color within.

BE THERE

For a tour of the Carpinteria Salt Marsh that includes a full day of nature exploration, visit the salt marsh display at the Santa Barbara Museum of Natural History or its Sea Center at the Santa Barbara Harbor.

For more information on the Carpinteria Salt Marsh, contact the UCSB Natural Reserve System at the Marine Science Institute, University of California, Santa Barbara, (805) 893-4127.

Carpinteria Marsh Park: For information, call Bob Nisbet, public works director and project manager, city of Carpinteria, at (805) 684-5405, Ext. 402.