Estuary Explorers Quiz – Question #3

Ecological Restoration

Look across this landscape. What are some of the urban impacts that pose constraints to future tidal  wetlands restoration efforts?

• Urban development: These wetlands are bound by housing, commercial, and industrial developments. Light, noise, air, and water pollution are all generated by the surrounding developments and the wetlands require a buffer from these edge effects in order to prosper.
• Poor soil conditions:  Much of the soil here is compacted, fine-grained, and saline. In many instances it is laden with gravel, asphalt, or other debris left behind by former industrial land uses. These conditions make it challenging to establish vegetation.
• Restricted Tidal Connection: Levees and dikes separate much of Los Cerritos Wetlands from the tidal waters of the San Gabriel River and Alamitos Bay.
• Oil production: Ongoing oil operations act as a constraint to the expansion of  wetlands habitat.
• Fragmentation of the land: These habitats are fragmented by roads, fence lines, water ways, levees, development, etc.
• Trash and Water Quality: Urban developments within the 640 square miles of the San Gabriel River watershed contribute to the trash that enters the River year-round. Los Cerritos Wetlands is located at the terminus of the watershed, therefore it is subjected to all of this trash and the poor water quality that is associated with urban run-off. While mature estuarine systems can act as watershed filters before reaching the ocean, too much pollution makes it difficult to restore tidal wetlands.
• Invasive species: A wide variety of non-native plant species like mustards and ice plants invade Los Cerritos Wetlands and compete for limited resources with native plant communities. Furthermore, non-native animal species like European starlings compete with animals for niches in this ecosystem.