eelgrass in the estero

by Kyle Pinjuv

The Estero Americano, a 127-acre preserve located on the southwestern border of Sonoma County, is home to a variety of plant and animal species. The adjacent tidal estuary that acts as the border between Sonoma and Marin County is part of the Gulf of the Farallones National Marine Sanctuary and is considered one of the most important biological areas along the Northern California Coast. On the land, the Estero Americano has a variety of habitat types, including coastal prairie, perennial grasslands and northern coastal scrub. By protecting the land, we also help protect the estuary — and the life that thrives below the glassy surface of the water.

The Estero Americano.

There are many plant and animal species that reside in the waters of the Estero Americano. One species that goes mostly unnoticed by the recreationalist, the swimmer or even the environmental enthusiast is California eelgrass. Eelgrass, a type of seagrass, provides extremely valuable habitat for juvenile fish, as well as for crabs, scallops and other marine life. In addition to providing protection and habitat to the estuary’s many creatures, eelgrass also improves our water clarity by filtering polluted runoff, balancing the aquatic system by absorbing excess nutrients, and even sequestering carbon in the sediments below. Because of its many benefits to the underwater ecosystem, eelgrass is considered to be a keystone species, defined as a species on which other species greatly depend within the same ecosystem.

Eelgrass bed (photo credit to

​Eelgrass habitat has been lost worldwide primarily because of human-induced degradation, like dredging, urban development and heavily polluted agricultural runoff. Great strides have been made to reduce the loss — and even to restore some eelgrass habitats over the past few decades. The ecological and economic importance of this species has been recognized by organizations and agencies throughout the United States and new projects to protect and restore it are on the rise. Recently, Sonoma Land Trust allowed the California Department of Fish & Wildlife to access the estero from our Estero Americano Preserve to conduct eelgrass surveys that will inform the larger database of eelgrass habitat zones and areas containing marine species of concern. The effort to restore this species is reliant on participation from private landowners, organizations, government agencies and recreationalists. It provides a unique opportunity to connect with our partners by sharing the common goal of learning about and protecting the land above … and the water below.

​Kyle Pinjuv is an assistant stewardship project manager at Sonoma Land Trust.