The San Francisco Estuary Invasive Spartina Project (ISP) treats and removes invasive Spartina (cordgrass), protecting native tidal marshes and mudflats across a 70,000-acre project area in San Francisco Bay. Thank you to all partners for your dedication and involvement in this critical and ongoing work!
The Invasive Spartina Project team and our partners are creating a world where Ridgway’s rails can thrive in native wetlands. Our goal has always been to maintain and expand native habitat for rails, shorebirds, and other wildlife by removing invasive Spartina before it replaces native marsh vegetation and degrades critical food resources found in mudflat habitat. Over more than 20 years of work, we are seeing visible results and on a large scale. Sites that were formerly dense monocultures of invasive Spartina are now rich in habitat, restored with native plants. Biologists have observed rail populations expand to four tidally-restored former salt pond sites in the Eden Landing Ecological Reserve, as well as several other restored salt ponds at Bair Island and Alviso (more below). The team is currently planning to resume treatment in the next few years at the final sites of the estuary. It is increasingly important for Bay Area restoration leaders to help the public understand the need to control and treat invasive Spartina in order to achieve the long-term vision of healthy habitat for endangered Ridgway’s rails and other species that are dependent on our native tidal marshes and adjacent mudflats. The partners of the Invasive Spartina Project are excited to engage with community groups and agencies to share future plans, and receive broad input as we plan for phased treatment and revegetation that protects rails and healthy tidal marshes.
Invasive Spartina removal and prevention, native tidal marsh and upland ecotone plantings, and high tide refuge island construction are successful restoration methods that are increasingly becoming integrated into living shoreline efforts in the region. The State Coastal Conservancy and the San Francisco Estuary Institute are working with a coalition of landowners and resource managers on the Regionally Advancing Living Shorelines Project, which seeks to transfer knowledge and share best design and constructability practices and build capacity for nature-based shoreline adaptation in the region.
The next Living Shorelines Collaborative meeting is on March 13 and will include presentations by project managers on how to better integrate invasive and native Spartina considerations into your wetland and living shorelines projects. All are welcome! To sign up for the zoom meeting, please email Emily Corwin at emily@sfei.org.
Read on for more project highlights from October 2024 to February 2025.
Restoration:
The restoration team kicked off the revegetation planting season in November with a field trip to long-time plant propagation partner, The Watershed Nursery Cooperative, to tour the facilities and to learn more about nursery best management practices. The restoration team is now busily wrapping up their 14th successful season planting natives with help from project partners SOLitude Lake Management and RECON Environmental. Project crews planted more than 18,000 natives at nine sites in the central and south Bay with the goal of rapid habitat enhancement for Ridgway’s rails and other wildlife dependent on tidal marshes.
Monitoring and Treatment:
In January, project partners conducted the winter round of survey and removal of Chilean cordgrass (Spartina densiflora) at historic infestation sites around the San Francisco Estuary. In the early years of the project, large infestations of S. densiflora had been reduced with a combination of treatment methods. The population has been reduced so significantly that the crew can switch to targeted manual removal of any S. densiflora plants as they are detected by the biologists in the field. At this point in the eradication process, most plants detected are only seedlings or small plants less than a year old. As these plants are removed, they are bagged and disposed of off-site.
The winter round of S. densiflora management has concluded and only six seedlings were found. With S. densiflora approaching full eradication from the Estuary, the team now focuses on high-scrutiny surveys of areas where S. densiflora was detected within the previous five years (the estimated length of seed viability for this species). A hybrid between S. densiflora and native Pacific cordgrass (S. foliosa) was also found near a detection from a previous year. The plant was “tarped” (covered with thick landscape fabric staked firmly to the substrate) to inhibit photosynthesis and slowly starve the roots over the next few seasons.
The Invasive Spartina Project team will be recruiting seasonal staff for the next monitoring and treatment season soon. Please check job postings online.
New tidal marsh restoration projects will expand the work area of the Invasive Spartina Project. The project team is currently planning the next season’s monitoring and treatment season as well as looking ahead to future years. If you are planning any tidal marsh restoration, please plan ahead and contact us at info@spartina.org!
California Ridgway’s Rail Monitoring:
Biologists began call-count monitoring of Ridgway’s rails on January 15, and the season had an exciting start. For the first time ever, staff detected Ridgway’s rails during surveys at Eden Landing Pond E8A and at Knapp Tract (Pond A6) in Alviso (eight birds counted at Knapp Tract!). Both sites are recent South Bay Salt Pond Project restoration marshes that are rapidly developing into Ridgway’s rail habitat. Rails continue to increase in number in the Eden Landing Ecological Reserve, at North Creek Marsh, with over 20 rails detected during the first round this year. The rail population in this area is likely increasing in response to the spread of native Spartina that was planted by the project’s Restoration Program, which has propagated and outplanted more than 50,000 native seedlings at this site since 2012.
Field crew members also detected rails at Inner Bair Island and Central Bair Island this summer while conducting invasive Spartina inventory. In order to increase the chance of detecting rails at these sites during the rail survey season, the rail monitoring team added a transect and additional stations in the area, leading to confirmed rail detections at both sites as of February 24.
Prior to the season start, project biologists joined partner biologists from Point Blue Conservation Science, California Department of Fish and Wildlife, California Department of Water Resources, East Bay Regional Park District, and U.S. Fish and Wildlife Service to practice rail surveys at Stege Marsh and Meeker Marsh in Richmond. This site is perfect for calibration surveys since it is adjacent to the Bay Trail and a prime spot for seeing Ridgway’s rails darting across open channels and hearing them call from the extensive native Spartina meadows.
Thank you!
Thanks to the wide range of collaborating organizations and dedicated staff and contractors that make this work possible including: State Coastal Conservancy, US Fish and Wildlife Service, San Francisco Bay Restoration Authority, East Bay Regional Park District, California Dept. of Fish and Wildlife, Port of Oakland, SF Bay Joint Venture, California Invasive Plant Council, Olofson Environmental, Inc., Valley Water, and more than 150 project landowners, partners, and contractors. Together, we are working to protect the Bay’s shorelines, bolster the native green infrastructure, and thus help increase regional resilience to climate change.
If you are working at sites along creek mouths, shorelines, or any waterways that connect to the Bay, please get in touch with our team at info@spartina.org.