San Mateo
Creek
There is a little piece of
natural California tucked into the south eastern edge of
Orange County and the northern fringes of San Diego County.
It's a free flowing stream known as San Mateo Creek. It
rises in the Santa Ana Mountains within the Cleveland
National Forest. Most of its headwaters are included with
the federally designated San Mateo Canyon Wilderness.
Leaving the Forest the stream flows across the northernmost
portions of the Camp Pendleton Marine Base. Just before it
enters the ocean at San Mateo Point, it enters the San
Onofre State Beach, a unit of the California State Park
system.
This
natural area provides an almost pristine ecological
corridor from the habitats of the 5000 foot peaks of the
Santa Ana mountains to sea level. Its importance is
underscored by the World Wildlife Fund's only ecological
inventory that rated the area around San Mateo Creek as the
most ecologically important in all of the United
States.
If
you are a surfer, you love San Mateo Creek as a source of
sand and gravel to build the world famous Trestles break
south of San Clemente. As an undeveloped watershed, it is
almost unique in Southern California in that it's winter
runoff is still clean thus not forcing surfers to leave the
winter waves to avoid pollution related
aliments.
For
me San Mateo Creek holds one more fascination. It is the
southernmost known spawning and rearing habitat for any
species of Pacific Salmon, specifically the southern
steelhead.
Here
is one that we found on an expedition to look for the fish
in August of 1999. Lead by Alex Vejar of California Fish
and Game we seined the summer isolated pools looking for
steelhead and removing exotic species. We located about a
half dozen juvenile steelhead on that
trip.
Steelhead
were confirmed to using the creek to spawn and rear when
Toby Shackelford, a student at nearby Saddleback Community
College, caught one on cheesebait during the winter of
1998-99. Toby reported his find to his professor and the
state game department was notified.
Studies
performed on these fish confirmed that they were southern
steelhead, a distinct population of oncorhynchus mykiss,
the steelhead trout. These southern steelhead are unique to
Southern California and are a federally listed endangered
species. These steelhead are an older genetic form of the
better known fish that Northwest and Alaskan anglers
prize.
It
is thought that during the last ice age, all of the
steelhead stocks migrated south to find suitable habitat
and lived in the Southern California/Baja California area.
As the climate warmed fish again began to use habitat to
the north and they eventually evolved into newer
populations that were adapted for the cooler wetter
habitats farther north. The southern steelhead continued to
occupy its preferred Southern California habitat, until
recent human activities reduced it population by 99% to
perhaps 500 adults.
Sierra
Club is at work trying to protect this habitat in South
Orange County. You can visit their project website
at Friends of the
Foothills.