Crissy Marsh facts for kids
Crissy Marsh is a special wetland area in San Francisco, California, United States. It's a place where fresh water from the land mixes with salty water from the bay. This mix creates "brackish" water, which is perfect for many kinds of birds. These birds travel along a route called the Pacific Flyway.
Crissy Marsh covers about 130 acres on the northern tip of the San Francisco Peninsula. Long ago, much of this natural salt marsh was destroyed. It was turned into an airfield called Crissy Field during World War I and World War II. But now, the airfield is gone, and the marsh has been brought back to life. It's a home for lots of amazing wildlife along the San Francisco coast.
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A Look Back: Crissy Marsh's History
Long ago, in the late 1700s, the Ohlone people lived here. They were Native Americans who gathered food from the bay. When the Spanish arrived in 1776, they called the area "El Presidio." This is where the name Presidio comes from.
In 1846, the U.S. Army took over the land. They used it for dumping waste and later built an airfield. Crissy Marsh was part of this military land during World War I and World War II. The airfield was named after Major Dana Crissy, an Army artilleryman.
After years of military use, the land needed help. Cleanup of harmful materials began in 1997. The marsh was then restored between 1998 and 2000.
Bringing Crissy Marsh Back to Life
The San Francisco Bay has lost over 90% of its wetlands since the mid-1800s. This happened because people changed the land to build things. Losing these wetlands meant less habitat for animals and plants, and poorer water quality.
In 1994, a plan was made to restore Crissy Field. The main goals were to bring back the natural tidal wetland. This would create a healthy home for plants and wildlife. It would also give people more chances to enjoy the Presidio.
The restoration of Crissy Marsh started in 1997. Workers removed almost 90,000 tons of harmful materials from the area. This was much more than the 15,000 tons they first expected!
Between 1997 and 2000, 40 acres of natural habitat were restored. This included 18 acres of tidal marsh and 22 acres of sand dunes.
What Was Done During Restoration?
During the project, about 100,000 native plants were planted or seeded. These plants belonged to 73 different native species. Workers also planted 104 Cypress trees.
They removed 230,000 cubic yards of soil and 15,000 tons of rubble. About 130,000 plugs of salt grass were grown and planted. A walking path, about 1 and 1/3 miles long, was also created along the shoreline.
A huge amount of old asphalt and concrete, about 70 acres, was removed and recycled. The National Park Service and the Golden Gate National Parks Conservancy managed this big project. The restored Crissy Field reopened to the public in 2001.
Keeping an Eye on the Marsh: Monitoring Program
After the restoration, a special program was started to watch over Crissy Marsh. Experts from the Parks Service and the Environmental Protection Agency monitor the area. They check things like water levels, how the land changes, water quality, and the health of the plants.
Since 1999, a company called Philip Williams and Associates has been watching the water and land changes. They measure water levels and survey the beaches and marsh. They found that the biggest changes happened in the first 18 months after restoration.
To check water quality, a special device was placed under a footbridge in 2001. It records water temperature, oxygen levels, and saltiness every 30 minutes. Scientists also monitor how much mud builds up using special tools.
Every year since 2000, the plants in both the dunes and the marsh are checked. This helps make sure the native plants are growing well.
Amazing Plants and Animals of Crissy Marsh
The restored salt marshes and dunes at the Presidio are now a thriving home for many plants and animals. One challenge is dealing with "invasive species." These are plants that are not native to the area. They can grow too much and crowd out the native plants.
Crissy Marsh is a fantastic place for bird watching. Over 200 different bird species have been seen here! Many bird watchers come to enjoy the diverse array of birds.
The area is also home to some very special animals. There are as many as 35 species that are endangered, rare, or threatened. These include the California Red-Legged Frog, the Mission Blue Butterfly, and the San Francisco Garter Snake. Protecting these animals is a very important part of the marsh's future.
