Petaluma Marsh/River Area

(www. wikipedia.org/wiki/Petaluma,_California)

This is an aerial view of the town of Petaluma, California. It is in Sonoma County, about 40 miles north of San Francisco. You can see the Petaluma River which runs through town. In the back ground are the Sonoma Mountains, which are east of Petaluma. The wetlands area is at the top of the picture.

The Petaluma River is not really a river. It is a tidal slough. The town was able to call it a river to get government money for dredging (visitpetaluma.com) so that the debris and silt that builds up from the rains and run off can be removed. This prevents flooding and allows boats to travel without hitting the bottom. The Petaluma River is a tidal slough because it is affected by the oceans tides. I have seen the water in the river so low all you could see was mud and so high I thought it would flood the downtown (Wetlands, 2009).

On the website at www.visitpetaluma.com/pdf/Shollenberger.pdf I learned that the Sonoma Mountains, which are between Napa and Sonoma County, are three to five million years old. The biggest mountain was a volcano.

The area that I observed is on the southern edge of Petaluma. It is a wetland area, a tributary, where the Adobe Creek runs into the Petaluma River. The River Heritage Center in Petaluma describes this area as the Petaluma Marsh/River area. On their website at www.petalumarhe.org/files/Petaluma_marsh.pdf I learned the Petaluma Marsh/River area “is the largest remaining intact tidal marsh within the San Francisco Bay Estuary”. Information on this website states the marsh/river area is composed of 5,000 acres of wetlands ecosystem. 12 miles of the Petaluma River run through this area and empty into the San Pablo Bay. Ducks, egrets, herons, bats, 25 species of fish, burrowing owl, ferruginous hawk, salmon, Dungeness crab and many other living things are found in this area. There are mudflats, ponds, and marshes. I saw grasses, reeds, flowers, lots of birds, very few rocks, mountains in the background, and butterflies.

About 10 million years ago this area and valley was covered with ocean water that was not very deep. The California coast was and is an area with many tectonic faults. As the faults moved the earth the continent shifted. Mountains were pushed up and valleys were created. About three to five million years ago, when the Sonoma Mountain range was formed, this area of marshes and wetland was 1,000 feet deeper than it is now (Chavez, 2002).

This is a picture of Adobe Creek. The water is very muddy. There are no real banks. Along the banks is what looks like grasses to me. The water is not pretty. I remember, from high school, that students helped restore this creek and bring back the Steelhead Trout. In 1982 the creek was dried up, full of trash and almost dead. It has been cleaned up and restored which helped save a species of steelhead trout from becoming extinct (Petaluma Visitors Center, 2009). The creek starts from the Sonoma Mountains in the east and runs into the Petaluma River which opens up into San Pablo Bay. San Pablo Bay is really just the northern portion of the San Francisco Bay and opens out into the Pacific Ocean.

The area I observed which includes Adobe Creek is a tributary. It is a stream that flows into a river and carries the water from the Sonoma Mountains. Also the area is a tributary because the Petaluma River flows into a bay which takes the surface water out to the ocean. Adobe Creek would have evolved after the Sonoma Mountain range was created – 3-5 million years ago – as a way for the water from the mountain to drain down and out into the ocean.

This is what I observed to be a pond south of Adobe Creek. There are lots of birds and grasses. When you walk around the pond there is an area where you see a marsh and the Petaluma River. I thought this was a natural pond but at the Audubon Society website I learned this is where the dredged material from the Petaluma River is placed Before the dredged material was put here it was a wetland where the water from the Petaluma River would go when it over flowed (Chavez, 2002; Madrone Audubon Society 2004).

Common Tule

Scirpus acutus occidentale – Common Tule variety occidentalisSpecies Schoenoplectus (bulrush) Family – cyperaceae (sledges) Class Liliopdida Monocotyledonous (flowering plants) Superdivision Spermatophyta (seed production) SubKingdom Tracheobronta (vascular Plants) Kingdom PlantaeaA Perennial herb, native to California(plants.usda.gov)

This is a picture of what I thought to be a kind of grass. It was growing in the pond, along side, into Adobe Creek, and all over the wetlands area. In order to identify the plant I researched names of plants found in this area. I learned that tule plants need water year around, grow in wetlands areas and fit the description of the plants I observed (.visitpetaluma.com). I could see that the ends of these plants once had something that flowered. Now the ends had what was left of a dead flower. The photo of the Common Tule (Scirpus acutus) best matches what I observed. The Common Tule is described as a bulrush and “native to freshwater marshes, lakes and stream banks throughout lower elevations in California and much of North America” (calfloranursery.com).

Evolution of the Common Tule: The plant kingdom evolved from algae’s. In the Paleozoic Era, around 410 million years ago the first vascular plants appeared. The first seed plants appeared about 360 million years ago, and flowering plants in the Cenozoic Era, about 130 million years ago. The Common Tule is a sedge or from the family of cyperacae which evolved from flowering plants. Sedge stems are usually solid and triangular in cross section. The stems are long and leaves are flat. They grow to four feet in shallow water and spread by tubers or rhizomes that grow underground (Cattails, 2010).

Coastal Tidy Tips

Kingdom Plantae Subkingdom Tracheobionta Subclass Asteridae Order Asterales Family AsteraceneSpecies Layia Platyglossa (Tidy Tips)(.plants.usda.gov)

This flower is growing all over the land surrounding the Adobe River and marshes. The petals are yellow in the middle and white around the edges. I identified the plant on the website califlora.org. There are many kinds of Tidy Tips. This species is native to California. The Platyglossa is a coastal Tidy Tip. They are from the Aster family. They evolved from vascular plants that produce seeds and flowers (Tidy Tips/plants.usda.gov).

This is a Black-Necked Stilt. I saw several of these birds in the pond. They have white bellies and a black back and head. Their legs are really long and pink. I watched them eat from the bottom of the pond. Their scientific name is himantopus. They are a shorebird. Their species is humantopus humantopus mexicanus. They come from the family called recurvirostridae which are all wading birds with extremely long legs, small heads and long slender bills. Mostly this group is either stilts or avocets. They fall into the Order category as charadriiformes which are birds that fly, live in open country or water, nest in the ground and feed on animal matter found in or near water. They are in the Class of Aves. Aves are warm-blooded, beaked vertebrates covered with feathers and who have wings (britannica.com).

The Evolution of the Black-Necked Stilt. The evolution of birds is thought to go back to the Jurassic Period. There are different ideas about their evolution but the theories I read about link them to reptile like prehistoric animals. A fossil was found in Germany which is called Archaeopteryx and is prehistoric dinosaur with wings. There are different theories about the exact evolution of birds. Dinosaurs, reptiles and fish fossils have been found with characteristics of birds, including the wings. Modern bird fossils go back to the early Tertiary period (Origins, 2007).

Mute Swan

It is not a native bird to the area. The swan’s tribe is Cygnini. The Mute Swan originated in northern and central Eurasia. They are all white, their bill orange, neck long, and feathers are white. Their chicks are gray and white (allaboutbirds.com). They come from the family of Anatidae which are geese, ducks and swans. The class is Aves or modern birds (britania.com). They are found in most parts of the world. Most likely they were brought to North America by people. Their ancient evolution is the same as the Black-necked Stilt.

Rocks

During the end of the Pliocene Epoch, about two million years ago, volcanoes erupted. The lava from Sonoma Mountain hardened into igneous rocks. Most of these are granite rocks. Basalt is found in the Sonoma Mountains. Another common rock, formed from the erosion of older rocks and material that washed off the mountains, was sedimentary rocks. The erosion of gravel turns into conglomerate rocks, sand into sandstone rocks and clay into shale. When sedimentary or igneous rocks are buried deep in the earth they become metamorphic rocks. Metamorphic rocks are not found in the area I am describing. Rocks in this area are also moved by tectonic movements (Ford, 1975).

There were not many rocks to found in this wetland area. I found these on the shore off an inlet pool of water next to the Petaluma River. They are light grey with white lines and spots. The rock is very hard and mostly smooth. There are white grains. This rock has characteristics of granite: fine grained, near tectonic plate and area of mountain building. It has grains which are rocks from an earlier date (Monroe, 2009).

There were many of these rocks in all sizes on the banks of the pond. The rocks are not as hard as the granite and look similar to the cracked mud bank. It looks like they are formed from the mud, gravel and the debris that flows into the pond. There is gravel in this area as well. It looked like it would break if I touched it but it did not and it was a hard rock. It is very rough, has holes in it and I can see different kinds and sizes of rocks and small grains. This is a sedimentary rock. It fits the characteristics of a sedimentary rock. It looks like it is composed of gravel, sand and silt. It is also a conglomerate. It is (Monroe, 2009)

References

Black-Necked Stilt and Mute Swan. Retrieved from www.britannica.com on July 16, 2011.

Cattails. (2010). http://www.ipm.ucdavis.edu/PMG/WEEDS/cattails.html#content retrieved on July 17, 2011.

Common Tule and Tidy Tips. Retrieved from www.plants.usda.gov/java/profile?symbol=LAPL) on July 16, 2011.

.Chavez, C. (2002). Self guided tour of shollenberger park. Retrieved from www.petalumawetlands.org on July 15, 2011..Ford, R. (1975). Geologic and hydrologic data. Retrieved from

http://www.sonoma.edu/users/n/norwick/Document/Ford/gws2.html on July 20, 1011

Madrone Audubon Society. (2004). Retrieved from (www.audubon.sonoma.net/birding/Shollenberger.html on July 16, 2011.

Monroe, J. and Wichander, R. (2009). The changing earth: exploring geology and evolution. Cengage pub.

Mute Swan. Retrieved from www.allaboutbirds.com on July 16, 2011.

Origin and Early Evolution of Birds. (2007). Retrieved fromwww.geologyrocks.co.uk/tutorials/originandearlyevolutionbirds on July 16, 2011

Petaluma. (2008) Photo retrieved from wikipedia.org/wiki/Petaluma,_California on July 16, 2011.

Petaluma Visitors Center. (2009). Retrieved from www.visitpetaluma.com/pdf/Shollenberger.pdf on July 14, 2011.

Scollenberger Plants and Animals. (2009). Retrieved from www.petalumawetlands.org on July 15, 2011.

Tule and Tidy Tips. Retrieved from www.calfloranursery.com/pages_plants/pages_s/sciacu.html) on July 16, 2011

Wetlands Campaign. (2009). Retrieved from www.petalumarhc.org/files/Petaluma_River on July 14, 2011..