[5] Restored Salt Pond at the Eden Landing site (Cris Benton)
Goals and Benefits
Restoring the wetlands of the San Francisco Bay will provide more habitats for animals, protect endangered species, improve the bay’s water quality, and protect Bay Area cities from sea level rise.
Restoration Goals
The restoration of the salt ponds has three main goals:
1. Restore and enhance wetland habitats
2. Provide wildlife-orientated public access
3. Provide flood management in the South Bay [2]
1. Restore and enhance wetland habitats
2. Provide wildlife-orientated public access
3. Provide flood management in the South Bay [2]
Habitat Restoration
The wetlands in San Francisco are an important wintering ground for migratory shorebirds and waterfowl. In the past 150 years, Diking and filling have destroyed the habitats of native species, resulting in a dramatic decline in their populations. Many endangered and threatened species such as the Salt Marsh Harvest Mouse, the Snowy Plover, and the California Clapper Rail reside in San Francisco’s salt marshes and salt ponds [5]. Overall, the salt marshes in the South San Francisco Bay provide habitat for over 100 million water birds throughout the year [7].
Click here to learn more about species that live in the San Francisco Bay.
Click here to learn more about species that live in the San Francisco Bay.
Salt Marsh Harvest Mouse
[9] Salt marsh harvest mouse on pickleweed
The endangered Salt Marsh Harvest Mouse is a small rodent that weighs less than a nickel. The harvest mouse only lives in the San Francisco Bay in high marsh zones densely packed with pickleweed. This specific habitat is rare in the bay because of the presence of levees and activitives such as diking and filling [9]. Over 60% of salt marsh has a high marsh zone that is not wide enough to support a harvest mouse population. In addition, there are very few connections between marshes with suitable habitats, making it difficult for harvest mice populations to move [8]. Restoration of the salt ponds will continue to create and connect the pickleweed habitat necessary for harvest mice to thrive.
Click here to learn more about the salt marsh harvest mouse.
Click here to learn more about the salt marsh harvest mouse.
California Clapper Rail
[10] Clapper rail nests near urban areas are threatened by house cats
The populations of endangered California clapper rails have declined due to habitat loss. Much of the suitable habitat for this bird is small, fragmented, and close to urban areas, increasing the risk of non-native predation by house cats and red foxes. Currently the Don Edwards National Wildlife Refuge is managing and restoring the habitat to make it less suitable for non-native predators to support clapper rail populations [10].
Snowy Plover
[11] Snowy Plover
The endangered Western snowy plover nest on dry former salt evaporation ponds in the South San Francisco Bay. In 2010, restoring 330 acres of salt pond to tidal marshes displaced 23,000 California gulls from their nesting grounds. This caused them to invade the Western snowy plover habitat, further endangering the already fragile population [12]. Restoration of the snowy plovers includes removing posts that provide perches for their predators and adding oyster shells to help camouflage the white birds eggs from the brown and red soil of the evaporation ponds [11].
An issue facing the snowy plover population is the conversion of salt ponds to salt marshes, which reduces their habitat, but creates a healthier ecosystem overall. Until the introduction of salt ponds, snowy plovers were probably not native to the bay, but today this area is a crucial nesting ground for the global population. Currently two options have been proposed to face this issue. The first is to open only half of the salt ponds to the tides, leaving enough habitat for snowy plover nesting. Restoration advocates are pushing a different goal of restoring 90% of the salt ponds to salt marshes, which will mostly likely eliminate the snowy plover population in the bay [12].
An issue facing the snowy plover population is the conversion of salt ponds to salt marshes, which reduces their habitat, but creates a healthier ecosystem overall. Until the introduction of salt ponds, snowy plovers were probably not native to the bay, but today this area is a crucial nesting ground for the global population. Currently two options have been proposed to face this issue. The first is to open only half of the salt ponds to the tides, leaving enough habitat for snowy plover nesting. Restoration advocates are pushing a different goal of restoring 90% of the salt ponds to salt marshes, which will mostly likely eliminate the snowy plover population in the bay [12].
Visiting the Ponds
[12] Overlook near visitor's center
The South Bay Salt Pond Restoration has worked to increase the area of the restored wetlands that is accessible to the public. There are visitor centers at each of the three restoration sites (Alviso, Eden Landing, and Ravenswood) with exhibits, observations, and programs such as bird migration walks. In addition, there are more than 30 miles of trails that take hikers and bikers into the salt marshes. Waterfowl hunting, fishing, and boating are permitted in designated areas [2].
Enhancing Flood Management
Salt marshes provide many benefits to humans, including protection from floodwaters. On the coast, salt marshes act as natural sea barriers because the salt marsh grasses prevent erosion, reduce wave damage, and limit flooding [14].
The South San Francisco Bay is home to the Silicon Valley. Many of these businesses are at or below sea level, which puts them at a high risk for flooding due to sea level rise [2]. The Alameda County Flood control and Water Conservation District is working with the restoration project to design flood protection channels [18]. Salt pond restoration and flood channel improvement will help protect these cities from the impacts of climate change.
The South San Francisco Bay is home to the Silicon Valley. Many of these businesses are at or below sea level, which puts them at a high risk for flooding due to sea level rise [2]. The Alameda County Flood control and Water Conservation District is working with the restoration project to design flood protection channels [18]. Salt pond restoration and flood channel improvement will help protect these cities from the impacts of climate change.
Further Benefits
Due to human activities, the bay's water quality has declined because of increased pollutants such as pesticides, sewage, metals, and urban runoff. The loss of tidal marsh has further decreased the water quality because wetlands naturally filter pollutants from the water [2]. Restoring salt ponds to tidal marsh will enhance the bay's water quality and help prevent harmful algal blooms [14].
