Tidal Channels are the subtidal, saltwater habitats that occur below the elevation of the low tidemark or Mean Lower Low Water (MLLW) where the substrate is continuously submerged underwater. This includes parts of the main channel and tidal creeks.
The floor of the Elkhorn Slough’s main channel is largely composed of organic matter, mud, sand, and gravel. The channel depth averages about 9.8 feet but is as deep as 32.8 feet near the Highway 1 Bridge crossing and as shallow as 1.6 feet at the head of the estuary.
Tidal creeks form extensive winding networks through the salt marsh and mudflats. From the air these tidal creeks are like beautiful abstract paintings of marsh, mud and water. These quiet waterways and pools serve as nursery grounds (i.e. food and shelter) for numerous species of fish. Tidal creeks serve an important function of water conveyance and drainage onto and off the marsh surface as well as the transfer of sediment and nutrients between marshes and the main channel.
Many species of birds hunt for fish in these deeper waters such as the Brown Pelican, White Pelican and the Caspian Tern. It is home to otters, seals, sea lions and fish. Below the surface, invertebrates such as clams and fat innkeeper worms find a home beneath the mud and become food for sharks, rays and otters.
We are currently featuring the following slough life from this habitat:
For a more complete look at the habitats of Elkhorn Slough, we recommend Changes in a California Estuary, available in our Bookstore.
For more about tidal habitats see the Elkhorn Slough Tidal Wetland Plan, Chapter 2.