Introduction
from Handbook
Welcome
to the San Diego National Wildlife Refuges which
was established to protect, restore and enhance rare and
endangered habitat, fish and wildlife and is the largest
remaining salt marsh on San Diego Bay. Rare eel grass
beds are nurseries for fish. Rare and endangered species
such as the Light-footed Clapper Rail, California Least
Tern, Western Snowy Plover and a state-listed bird, the
Belding's Savannah Sparrow, all make their homes and raise
their young here. Salt Marsh Bird's Beak, an endangered
plant, grows at Sweetwater Marsh. Hundreds of thousands
of birds migrating along the Pacific Flyway twice each
year use the Refuge as a place to rest and feed before
continuing on their long journeys north to Alaska and
down to South America. Sweetwater Marsh is home to over
270 species of birds, hundreds of thousands of invertebrates
and fast-diminishing marsh plants which support much of
the wildlife.
This
curriculum opportunity was created through a joint venture
of the San Diego Zoological Society, the U.S. Fish and
Wildlife Service San Diego Refuges and the Chula Vista
Nature Center to provide an educational adventure for
local students to learn about science and the local environment
in a hands-on manner. The curriculum program was designed
for fourth grade students and matches the state educational
science standards for fourth grade.
The program includes step-by-step information on how
to arrange for your field trip, pre-visit teaching lessons,
on-site curriculum and equipment, and a post-visit curriculum
to further the learning process. The on-site curriculum
is taught by the teacher and chosen chaperones. The Chula
Vista Nature Center will coordinate your visit and greet
you upon your arrival. 
The
Chula Vista Nature Center is not able, however, to provide
on-site teaching or supervision of students. Please note
that this unique field trip is only available to a teacher
and his/her class once the teacher has attended a mandatory
workshop, provided quarterly and free of charge at the
Chula Vista Nature Center.
The Refuge's first priority is to conserve the wildlife
and wildlife habitats of the San Diego National Wildlife Refuges. Therefore, this field trip opportunity
is only open to one classroom of approximately 32 students
per day. While ensuring that the reserve is not overly
impacted, this also provides each visiting class the opportunity
to enjoy this experience in a quiet natural setting. The
refuge trails are flat, wide and wheelchair accessible.
The hiking distance is about a mile maximum and would
be considered an easy trail. Comfortable, sturdy shoes
are recommended, however.
Before visiting, students should be divided into four
research teams: Clapper Rail, Least Tern, Savannah Sparrow
and Peregrine Falcon.
Each bird group will rotate among four 45-minute research
stations: Plankton, Plants, Animals, and Birds.
During each station, students will learn about the living
and nonliving components of the Refuge ecosystems and
how these components interact. The field curriculum consists
of an interactive activity designed to promote exploration
and learning and a data collection worksheet to be completed
and saved for the post-visit curriculum in the classroom.
Each station is conducted in a different area of the refuge.
See Refuge map for the location of each research area.
Pre-lessons were organized to prepare the students with
necessary background knowledge to enhance their learning
experience once on-site. A post-visit curriculum is provided
to guide students as they review, organize and publish
their field data. This real-life experience provides authentic
assessment of gained science knowledge.
For further information about this unique educational
experience, please contact the Chula Vista Nature Center
at 619-409-5903.
Habitats
The
San Diego National Wildlife Refuges has several
distinct wildlife habitats.
The salt marsh is characterized by salt-tolerant vegetation
such as Salt Marsh Rosemary, Alkali Heath, Pickleweed,
Cordgrass, Arrowweed and Batis. All of these plants have
developed strategies for dealing with the daily inundation
by tides and the salinity of the water. The soil is always
wet and permeated with burrows of fiddler crabs, clams
and other burrowing creatures. On the surface you can
see California Horn Snails and Channeled Basket Shells.
Many large shorebirds like willets, curlews and godwits
take advantage of the rising and falling tides to feed
on these invertebrates. The endangered Clapper Rail constructs
its floating nests in the cordgrass and the endangered
Savannah Sparrow needs to nest in the pickleweed.
Tidal channels meander through the salt marsh bringing
the life-giving salt water. In the channels live the long-jawed
mudsuckers and yellow-finned gobies that make up the food
of the Great Blue Heron and the white Snowy and Great
Egrets. Round stingrays and halibut can be seen swimming
in the channels and terns, Black Skimmers and Osprey can
be seen hovering over them in search of fish.
Mudflats are exposed at low tides. They are riddled with
the burrows of ghost shrimp, worms, clams and other invertebrates.
Then thousands of shorebirds of all sizes can be seen
intently probing into the mud for food. The birds have
different leg and bill lengths and each species searches
for different foods
The beach here is often covered with dead eelgrass and
human items (such as trash, chemicals) that wash down
from the watershed. At high tide it is used as a roost
by the larger shorebirds. As the tide recedes, hundreds
of tiny sandpipers scurry along the edge of the water
looking for isopods and other morsels on the surface.
The Coastal Sage Scrub habitat of the uplands of Gunpowder
Point has been degraded over the past century by human
activities. When the Kumeyaay people were living here,
they were able to utilize the plants and animals that
lived here to make a decent life. With the coming of the
kelp processing factory that employed 1500 people to make
the components of gunpowder, the creation of two levees
to impound water, the cottonseed oil storage facility
and then the farming, most of the native mammals, birds,
reptiles and plants disappeared. The Nature Center and
the U.S. Fish and Wildlife Service are now working together
to restore the uplands.
Plants of the Coastal Sage Scrub community such as lemonadeberry,
toyon, sagebrush, black, white and Cleveland sages and
bush sunflower are among those being planted by volunteers.
In time it is hoped the plants will mature enough to provide
shelter and food for displaced native mammals, birds and
reptiles such as the San Diego Coast Horned Lizard, Gray
Foxes and California Gnatcatcher.
Contact Barbara
Simon for more information.
