Invasive Species Program

Dwarf Eelgrass

Eelgrass is a grass-like aquatic plant that forms lush meadows in shallow, sheltered bays and estuaries. These meadows cushion our shoreline from wave energy, delay floodwaters, break down pollutants and support diverse wildlife. They also produce vast amounts of oxygen, which we all need to breathe.

There are two species of eelgrass in California. Pacific eelgrass, Zostera marina, is native to our coast and beneficial to the ecosystem. Dwarf eelgrass, Zostera japonica, is native to Asia and threatens to upset the natural balance of California's wetlands.

The recent introduction of dwarf eelgrass, which can be distinguished from Pacific eelgrass by its very narrow blades, is a serious concern to resource managers. Dwarf eelgrass invades mudflats, which are home to many creatures and vital feeding grounds for shorebirds.

Pristine coastal wetlands are rare in California and worldwide, and the invasion of dwarf eelgrass further imperils the little habitat remaining.

• Brochure:
  Stop the spread of dwarf eelgrass (PDF)
• 2009 Outdoor California magazine article:
  Eelgrass: Beneath the surface (PDF)