For California coastal wetlands, one may conjure up visions of vast mudflats with swarming flocks of shorebirds. This would alternate twice a day with high tides and equally wide areas of shallow water accompanied by teeming masses of ducks. A variety of fishes would flood onto the flats with the invading waters. Restricted to deep channels or hiding away in burrows at low tide, they would take advantage of the newly exposed mudflat fare. Surprisingly, this scenario does not fit the original description of most California coastal wetlands.

Most of the flow in local rivers and streams comes in a few winter months due to our Mediterranean climate. The steep, geologically young coastal terrain erodes rapidly and sediment production is high. Thus, many of the original coastal wetlands and lagoons opened to the ocean only during a few winter months. The declining flow and build up of sediment by ocean waves closed them off for the rest of the year. The resulting trapped water was low in salinity (15% or less) and often did not fluctuate with the tide. Such systems harbored few species and seemed barren since California has few aquatic species that can permanently inhabit such areas.

Larger bays, however, maintained openings at their mouth by force of tidal exchange. Early explorers testified to the shallow, dangerous nature of these openings. Even when tidal flow existed, it was dampened by shallow sills of sediment at the entrances. Such fully tidal conditions prevailed only in San Francisco, San Pedro, and San Diego (including Mission Bay) Bays, where prominent headlands maintained openings.

In the past, some of our most famous southern California wetlands, such as Ballona, Malibu, and Mugu lagoons, were only open to the ocean during the winter months. Even larger systems such as Newport and Morro Bay probably closed often. During the Gold Rush, the demand for safe harbors led to channelization and construction of jetties at the mouths of these and many other sites. Farms and other enterprises encroached upon the margins. Lagoons could not be allowed to close as man-made structures would be flooded. Ironically, extensive or complete tidal exchange is now considered desirable to prevent stagnation of the water.

Man-made changes in most wetlands attenuated the original low salinity estuarine conditions. Surrounding levees stopped inland invasion of salt water and blocked regular flow of freshwater into the system. With good tidal exchange, temperature and salinity closely paralleled local oceanic conditions. Many marine species, originally highly localized near the mouth of rivers and streams, became widespread in bays.

Increases in erosion from gold mining and logging before 1900 and from agriculture thereafter also impacted wetlands by tremendously expanding and filling them in with softy muddy sediments.

Additional coastal modifications included construction of piers and wharves. Many wharves in upper San Francisco Bay existed for many years in the low salinity waters. The construction of large dams on California rivers in the early 1900s reduced freshwater inflow. Subsequently, saltier water carrying wood-boring clam and worm larvae penetrated upstream. Within a few years, the disasterous destruction of wooden structures revolutionized the standards of marine construciton as well as stimulated support for several large marine biological studies.

The creation of many small dams and debris basins stopped the flow of sediments (as well as water) into coastal areas. Agriculture and increasing populations led to more extraction of water from the water table and less water to the coast. The lower water table also allowed salt water to invade further inland under the sediments. All of these changes contributed to tranforming extensive reaches of fresh and brackish marshes and lagoons to restricted bays and mudflats.

Several species of animals that thrived under these original conditions are not considered marine species, but are rare, threatened, or endangered today. Best known of them are the Tidewater Goby, Pacific Pond Turtle, Red-legged Frog, some coastal garter-snakes, Light-footed Clapper Rail, and Least Tern. Estuarine fishes prominent in the original lagoons were the California Halibut, Steelhead, Topsmelt, California Killifish, Threespine Stickleback, Staghorn and Prickly Sculpin, Bay Pipefish, Shiner Perch, Mudsucker, Arrow Goby, Diamond Turbot, and Starry Flounder.

The two high-profile game species, the California Halibut and the migratory Steelhead, are dependent on coastal lagoons for nursery grounds.

Today, four lagoons on Camp Pendleton in San Diego County best exemplify the original wetlands of southern California: Santa Margarita, Las Flores, San Onofre and San Mateo. Activities of the U.S. Marine Corps prevented encroachment of other kinds of civilization and continue to protect these natural conditions. Additionally, Malibu Lagoon is being restored by the California State Department of Parks and Recreation, with plans to re-introduce the Tidewater Goby proceeding there.

Other major southern California estuaries, Tijuana Slough, Mugu Lagoon and Carpenteria Marsh retain regular flow of "estuarinized" habitats of today. They remain undiminished as refuges for migratory birds and a wide variety of estuarine animals, but are not in their original condition. Hopefully more former or marginal wetlands will be restored further "back-wards" towards the original lagoons and wetlands they once were.

Dr. Swift is an Associate Curator of Fishes at the L.A. Natural History Museum where he works on the status and biology of freshwater and estuarine fishes.

**Footnote Source: Tidelines, is the Newsletter by Cabrillo Marine Aquarium. Please note also that the Cabrillo Marine Aquarium in San Pedro is a long established educational facility, that exists despite the City of Los Angeles not funding it properly. The citizens of San Pedro, marine biologists and environmentalists, have overcome the bureacracy of Los Angeles. The City of Los Angeles does not deserve credit for this Aquarium because they do not fund it adequately. However, the citizens, volunteers, scientists, children, environmentalists and educators that work hard to make it a success deserve the credit.**

Today, in 2001, just four years after 1997, when Camm Swift taught us about the Southern California Wetlands, we are making some progress, but threats to these imperiled ecosystems still exist. For example, the Tidewater Goby has been restored and recovered at Malibu Lagoon. However, the threat of breaching the Lagoon so that seawater can enter the Lagoon is a saltwater threat to the Tidewater Goby. Also, the increased sewage outfall from septics which adds nitrogen to Malibu Lagoon is a threat that imperiles the Lagoon.

Today, in 2001, opportunities for restoration and recovering abound. Opportunities waiting to happen. Time will tell! Humans from Europe, via their American colonies, have only been here with their covering of the Earth with cement and asphalt for about 150 years. In Los Angeles, the U.S. Army Corps of Engineers is a "misguided" force against nature lovers and liveable city advocates. The Sierra Club, Wetlands Action Network, and CalPIRG, have joined forces to take on the Engineers at the U.S. Army. The case is in front of the UNITED STATES SUPREME COURT about the NATIONAL ENVIRONMENTAL POLICY ACT (NEPA) and Ballona Wetlands destruction.

Abolishing the "Army Engineers" as an agency will not work, but lessening its power in civilian matters in Los Angeles is a proper goal. As we replace this federal agency of the "Army Engineers," we need to elevate other federal agencies such as USEPA (Environmental Protection Agency) and USFWS (Fish & Wildlife Service) to take the lead in regulating wetland delineations, open space, liveable cities, and nature protection in Los Angeles.

We need more Parks of the natural kind. The ecological and logical choice is CALIFORNIA STATE PARKS. Their influence is increasing in urban Los Angeles. Topanga, Los Angeles River, Baldwin Hills, Chino Hills, and Ballona Wetlands are examples of California State Parks' involvement. Their resource ecologists are the guiding forces to restore and recover wetlands at Malibu, Ballona, Mugu, and Bolsa Chica as Camm Swift recommended.