Saturday, November 22, 2008

(2) Waters Meet

To return to our present day, the Tijuana Estuary is a wetland
rarity. Many of California's estuaries and wetlands have been
destroyed because of highway and housing construction. Including
Oregon and Washington State, along with California, these special
wetlands are a necessity for the many kinds of migratory birds--
during seasonal change--that fly down and up the North and
South American coastlines. This migratory route is called the
"Pacific Flyway."

Now, with so few wetland stops available, the Tijuana Estuary is
a very important haven for these migratory birds--as well as for the
local birds who permanently make their home here. Besides being
a food source, the estuary is also a safe haven for birds to raise their
young.

I specifically came to volunteer at this estuary, because this is a
place "where the waters meet." This is a place where fresh water
intersperses with sea water, hence producing what is called brackish
water--a kind of salty water, if you will. The tides come and go in
the Tijuana Estuary, naturally bringing in fresh nutrients. These
provide a constant food source for the inhabitants of the estuary.
As for it being a safe haven, its high sand dunes protect the
estuary from the ocean, hence allowing safe nesting areas for
the birds who stop-over or make their permanent home in this
area.

But, now, let me be more specific. There are eight different kinds
of habitats within the estuary that mesh one into the other.

• Riparian: This habitat runs along the Tijuana River where fresh
water dominates.

• Uplands: Here desert plants--such as cactus--grow, a few inches
above the marsh.

• Salt Marsh: It is here where plants adapt to the changing water levels,
moving more into a salty environment.

• Ponds: These are now full of brackish water.

• Mudflats: At low tide the water rushes out of the estuary, leaving a
muddy flatland that exposes a waterlogged soil full of food.

• River valleys.

• Salt Pannes: These are poorly drained areas, where the salt content
can be three times that of ocean water.

• Dunes: These sand dunes protect a calm estuary from the sea.

As for food, the Tijuana Estuary is full of different forms of algae,
phytoplankton, benthic invertebrates, and bivalbe molluscus.
There are also fish, crabs, ghost shrimp, and worms.

And throughout the estuary there are indigenous "salt marsh" plants.
To name a few: Pickleweed, Glasswort, Heath, Rosemary, Sea
Lavender, Cordgrass; Saltwort, Marsh Bird's Beak, Shoregrass,
Saltgrass, Rabbit's Foot Grass, Tamarix, and Sea Fig.

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