Near Tijuana, a River Marsh Worth Its Salt

At first glance, Tijuana River Estuary, one of the few salt marshes remaining in Southern California, looks lifeless. But a closer look--or a look through binoculars--might reveal a marsh hawk, brown pelican, California gull, black-necked stilt, snowy egret, Western sandpiper and American kestrel--to name a few of the more common birds.

The estuary, about 1 1/2 miles north of the border dividing Baja and California, 15 miles south of San Diego, is an essential breeding ground and feeding and nesting spot for more than 170 species of native and migratory birds.

A flotilla of land-use agencies have shared control of what is officially known as the Tijuana River National Estuarine Research Reserve: the California Department of Parks and Recreation, the California Department of Fish and Game, and the U.S. Fish and Wildlife Service.

The greatest challenge facing these agencies--and the biggest threat to the estuary--is sewage discharges from Tijuana. The fast-growing city sometimes empties sewage into the Tijuana River, which in turn empties into the estuary. Border Field State Park and the estuary have been closed to public use several times as a result of such sewage spills. In addition, nearby Imperial Beach and Silver Strand State Beach are occasionally closed due to sewage-related problems.

The various resource agencies staff a nice visitor center that interprets marshland ecology. One good source of information is the pamphlet, “A Walker’s Guide: The Natural History of the Tijuana National Estuarine Reserve.” The brochure lists some of the more common birds and plants found in the reserve. Guided nature walks take place on Thursday afternoons and Saturday mornings.

From the visitor center, trails lead into the estuary and continue all the way to the Tijuana River mouth. At times of low water and low tide, the river can be safely crossed, but at times of high water and high tide, crossing can be very dangerous.

At Fifth Street and Iris, a second signed trail leads into the estuary. The path parallels the Ream Field boundary fence. On weekdays, you’re sure to see more helicopters hovering over this stretch of trail than appeared in “Apocalypse Now.” Most first-time visitors figure that they must be U.S. Border Patrol copters searching for illegal immigrants crossing the border. Actually, the helicopters from Ream Field are flown by Navy pilots who are practicing their takeoffs, landings and air-sea rescues.

Though the estuary is almost flat, it’s not completely flat, and very small changes in elevation bring changes in vegetation. At higher elevations are hillocks of coastal scrub, and at the very lowest elevations are mud flats. Between is a marshland of pickleweed and cordgrass.

For an interesting return route or an addition to your marsh hike, take a walk along wide, sandy Imperial Beach. Imperial Beach was named by the South San Diego Improvement Co. around the turn of the century to help lure Imperial Valley residents to build summer cottages on the beach. Waterfront lots could be purchased for $25 down and $25 monthly, and developers promised the balmy climate would “cure rheumatic proclivities, catarrhal trouble, lesions of the lungs,” and a wide assortment of other ailments.

In more recent times, what was once a narrow beach protected by a seawall has been widened considerably by sand dredged from San Diego Bay. There’s good swimming and surfing along Imperial Beach , and the waves can get huge. Wander up to Imperial Pier, built in 1912 and the oldest in San Diego.

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Directions to trail head: From Interstate 5 in Imperial Beach, exit on Palm Avenue. Go west 2 1/2 miles to Third Street. Turn left and drive half a mile to the visitor center parking lot for the Tijuana River National Estuarine Research Reserve.

Tijuana Estuary Trails

WHERE: Tijuana River National Estuarine Research Reserve.

DISTANCE: 1-6 miles round trip.

TERRAIN: Tidal creeks, marshland, dunes, sandy beach.

HIGHLIGHTS: One of the Southland’s most important bird habitats.

DEGREE OF DIFFICULTY: Easy.

FOR MORE INFORMATION: Contact Tijuana River National Estuarine Research Reserve, 301 Caspian Way, Imperial Beach, Calif. 91932, (619) 575-3613 or (619) 575-2704.