When a non-native hybrid cordgrass invades a salt marsh, what happens to the small creatures that live there?
An invasive species is a non-native species often introduced into an ecosystem either intentionally or accidentally by human action. They have a tendency to spread, disrupt ecosystems by changing physical processes, or otherwise reduce the habitat available for native species. Smooth cordgrass (Spartina alterniflora), an east coast plant originally introduced to stabilize the shoreline, has become invasive in San Francisco Bay Marsh ecosystems. Smooth cordgrass cross-breeds with native California cordgrass, producing “super hybrids” (Spartina alterniflora x foliosa) that grow much taller and denser than the native species. These hybrids can also survive at both lower and higher points in the intertidal zone. If hybrid cordgrass became established within the estuaries of Point Reyes, it could fill many of the mudflats used by shorebirds, drastically reducing the birds’ foraging areas. The small invertebrates that live in the sediment of salt marshes and mudflats are the food for migrating shorebirds and form the base of the food web.