Seasonal Wetlands

A Wetlands Preserve protecting 105 acres of seasonal wetlands forms more than half of Sunnyvale Baylands Park. Pickleweed and other salt marsh plants provide forage and shelter for many species. During the winter, rain water ponds in the seasonal wetlands providing an ideal habitat for waterfowl and shorebirds. Pickleweed, cattails and other wetland plants grow in areas saturated with water. As the water evaporates and recedes, shorebirds explore the muddy bottom for food. By summer, the water has dried up leaving behind plants that can survive the extreme wet and dry conditions of seasonal wetlands.

Wetland habitat has shelter, food, and space needed by the hundreds of birds that stay here year around or stopover on their winter migration. Wetlands are also important for replenishing groundwater for drinking, absorbing flood waters, protecting shorelines from storms, and filtering pollutants. Small fish, worms, and crustaceans thrive in wetlands and provide food for foraging wildlife. 

Benefits of Wetlands

• Decreased Flooding
  Heavy rains and runoff are absorbed by wetlands, limiting flooding in nearby areas. Replacing wetlands with development increases surface runoff from paved and covered areas, insuring overflow elsewhere. In the spring, wetlands slow the runoff from snow melt, preventing erosion and siltation farther down stream.
• Filtering of Pollutants
  Due to the high productivity of wetlands, pollutants are filtered out and used as nutrients by growing plants, microorganisms, and decomposition. Sediment- filled runoff can smother marine animals and choke fish. Wetlands slow the flow of water, allowing particles to settle out.
• Drinking Water
  Groundwater supplies for drinking are recharged as water absorbs through saturated wetlands. Overpumping of groundwater caused the land in Alviso and San Jose to subside by an average of 11 feet in the early 1900s.
• Nursery
  Small fish, crabs and invertebrates find shelter in wetlands from predators and fast moving waters. Larger fish and marine organisms use the wetlands for breeding.
• Wildlife Haven
  Attracted to the abundance of plants, worms, crustaceans, mice and fish, birds of all size find wetlands ideal habitat. Small birds find plenty of insects and in turn are eaten by larger birds like hawks and falcons.
• Open Space
  For people, wetlands provide a place to relax, away from the stresses of urban life. The air is fresher, views are wider and wildlife viewing is exceptional.Water-loving plants such as pickleweed, grow here even during the summer and fall when water has evaporated.