THE WETLANDS: ORANGE COUNTY’S EMBATTLED RESOURCE : PORTRAIT of a SALT MARSH

A salt marsh is one of three types of wetlands in Orange County. Fed by the ocean, it provides crucial habitat for aquatic life and birds--including several endangered species. Below, a closer look at this complex ecosystem. California Least Tern:

This nine-inch, gull-like bird flies high above marshes, looking for fish, then plunges into water to share its prey. Hundreds used to nest on Southern California beaches.

Brown Pelican:

With powerful wings and a pouch for collecting fish, this bird occasionally roosts in marshes. In the late ‘60s, DDT caused eggs to break before chicks hatched. Species is recovering and may be reclassified.

Cordgrass:

Hardy plant that survives long immersions in salt water.

Pickleweed:

A predominant marsh plant that rids itself of salt absorbed from the marsh by storing it in leaves that are eventually shed.

Black-Bellied Plover:

This small shorebird is commonly seen foraging for food on mud flats.

Belding’s Savannah Sparrow:

The only songbird in salt marshes, this five-inch bird nests exclusively in pickleweed, just above the high-tide line.

Light-Footed Clapper Rail:

A shy bird, about the size of a chicken, that weaves its nest in cordgrass. Orange County is home to more than 70% of the U.S. population, estimated in 1989 at 163 pairs. Predators include cats and the non-native red fox.

Arrow Goby:

Lives in mudflat burrows made by other animals. Young halibut dine on these fish.

Mud-Flat Animals:

Shrimps, crabs, worms, and other small creatures that live in mud flats find a plentiful supply of microscopic food in salt marshes. They, in turn, are food for birds and fish.

Migration Pit Stop:

Southern California’s coastal marshes provide places for birds to feed and rest as they migrate each fall and winter along what is known as the Pacific Flyway.

California endangered species list:

California Least Tern

Brown Pelican

Belding’s Savannah Sparrow

Light-Footed Clapper Rail

United States endangered species list:

California Least Tern

Brown Pelican

Light-Footed Clapper Rail

Marsh Pecking Order

Birds with long beaks tend to probe deep into the mud for small animals to eat, while those with short beaks may rapidly peck at the surface.

Semi-palmated plover: 0.5 in.

Western sandpiper: 1.1 in.

Willet: 2.6 in.

Dowitcher: 3.0 in.

Marbled godwit: 4.8 in.

Linked to the Ocean

Salt marshes are appendages of the sea. Tides pump seawater in and out of them, as a heart circulates blood through a body’s limbs. These wetlands wither and die when their ocean inlets are closed.

Tides: Regulating How Animals feed, Where Plants Grow

Low Tide (occurs twice daily)

Birds poke through exposed mudflats to snare small animals.

High Tide (occurs twice daily)

When mudflats are under water, small marine animals emerge to feed. Fish search for food in channels. Birds fly above, hunting fish.

Unusually High Tide

Tidewater can reach farther up into the marsh, depending on time of year and weather. Plants here can withstand the occasional immersion in salt water.

Inlets: Umbilical Cord to the Sea

Many Southern California salt marshes are only vestiges of what they were because large portions have been drained to make way for development. As a result, marshes may not be able to maintain there vital ocean links.

1) Inlets allow seawater to flow in and out of a marsh with the tide.

2) Birds and fish find plenty of small marine animals to eat in the shallow channels that an inlet creates inside a marsh.

3) Marsh plants take their moisture from the sea. They provide nesting and foraging habitat for some endangered birds and support other creatures.

When Inlets Close

As it slowly evaporate, seawater trapped inside a marsh becomes too salty for small marine life to survive. Birds lose a primary food source. Soil becomes too salty for some native marsh plants, which die. Creatures that depend on these plants lose habitat.

FRESHWATER WETLANDS

Salt marshes along the coast may be Orange County’s best-known wetlands, but they are not the only type. Two kinds of freshwater wetlands are found inland.

Riparian Wetland

These wetlands line freshwater creeks and rivers. Most have been paved and channelized, so few riparian areas remain. They are dominated by willow woodlands and a thick underbrush, which provide foraging areas for birds and animals. Local examples are Santiago Creek and Aliso Creek.

Freshwater Lakes and Marshes

Extremely rare, these wetlands are fed by runoff from mountains as well as underground water that surfaces. They are inhabited by waterfowl, including herons, ducks and Canada geese, fish and small mammals. Local examples are the Laguna lakes and the San Joaquin Marsh.