September 2, 2024

Brian M. Meux
NOAA Fisheries
Fisheries Biologist
West Coast Regional Office
777 Sonoma Ave. Room 325
Santa Rosa, CA 95404
brian.meux@noaa.gov

Re: Treasure Island Marina Replacement and Expansion Project (USACE #SPN-2022-00219)

Dear Brian Meux:

The Sierra Club has held a long-standing interest in preserving the health of San Francisco Bay in the face of sea level rise. To respond to this issue, we have created the Bay Alive Committee. Of major concern is the threat sea level rise poses to the Bay's shallow water habitats such as tidal marshes and tidal flats, beaches and eelgrass beds. We also recognize that the Bay Area's under-resourced, environmental justice communities are among the most likely to be impacted by sea level rise.

The Treasure Island Marina Replacement and Expansion Project poses a severe threat to the conservation of essential fish habitat. The proposed marina expansion project and associated new dredged channel would very likely have an adverse effect on eelgrass and eelgrass habitat located in Treasure Island’s Clipper Cove as well as in adjacent areas while providing little to no public benefit.

Eelgrass is a linchpin species for the long-term health of the San Francisco Bay which hosts an estimated 17% of California’s eelgrass. Eelgrass (Zostera marina) plays a critical role in the marine food web and bay ecosystem. Healthy eelgrass beds are a keystone of climate-resilient bays with its ability to mitigate ocean acidification, anchor shorelines, dampen waves, and store carbon besides providing rich habitat and critical fish nurseries. However, eelgrass is a notoriously difficult species to restore and to establish, leading to expensive and inconsistently successful conservation efforts.

NOAA’s consultation on this project with the U.S. Army Corps of Engineers (USCAE) and other government agencies should call for hydrodynamic analysis to investigate and assess the potential impact of this project on eelgrass, in line with NOAA’s California Eelgrass Mitigation Policy and Implementing Guidelines, particularly as hydrodynamic analysis was not conducted for the 2005 EIR evaluation of eelgrass impact concerns. NOAA should not concur with the proposed permit for this project if hydrodynamic analysis is not performed. Per NOAA’s California Eelgrass Mitigation Policy and Implementing Guidelines, the adverse impacts of this project are most appropriately addressed by avoidance. Unless hydrodynamic analysis can confidently affirm limited impacts, the project as designed should not be permitted.

The elements of the project that pose a threat to eelgrass are the dramatic expansion of docks and the dredging of a new entrance channel along the southern edge of the Cove. The new pilings, decking and entrance channel all pose significant risk of altering currents, sediment accumulation and scouring, per the NOAA Programmatic EFH Consultation with USACE For Construction & Maintenance of Overwater Structures.

Further, the project proposes to dredge the new entrance channel directly alongside historic eel-grass habitat per the Pacific Marine and Estuary Fish Habitat Partnership data layers webpage, especially eelgrass maximum extent.

As such hydrodynamic analysis is required to better understand the impact of this project on eelgrass habitat within the Cove and immediately adjacent to the mouth of the Cove, i.e. along the southeastern shoreline of Treasure Island, the southern portion of the eastern shoreline and the northern portion of the eastern shoreline of Yerba Buena island - all eelgrass habitat.

NOAA’s California Eelgrass Mitigation Policy and Implementing Guidelines states that “...parties should evaluate if and how the action may alter the hydrodynamics of the action area such that eelgrass habitat within or in proximity to the action area may be adversely affected.” The Guidelines further state that “Biologists should consider the potential for project actions to alter conditions of the physical environment in a manner that, in turn, reduce eelgrass habitat distribution or density (e.g., elevated turbidity from the initial implementation or later operations of an action, increased shading, changes to circulation patterns, changes to vessel traffic that lead to greater groundings or wake damage, increased rates of erosion or deposition)”. The necessity for this analysis in Clipper Cove aligns with a professional biological opinion calling for hydrodynamic analysis of the project by Keith W. Merkel, Principal Ecologist at Merkel & Associates, Inc., who has surveyed and monitored eelgrass within the Clipper Cove area of Treasure Island for two decades.

Further the proposed entrance channel would cut directly through an area of potential and current eelgrass habitat deemed likely to withstand the impact of 1.2 meters of sea level rise [See the San Francisco Bay Eelgrass Habitat Suitability Model.] Given that 1.2 meters of sea level rise is almost certainly locked-in by ongoing physical processes, this habitat is important for the conservation of essential fish habitat.

Even as the project poses a significant risk to essential eelgrass habitat, it would provide little to no public benefit. The proposed project is a private marina developed as a private amenity for private owners of landside development on Treasure Island. In addition, the marina is designed exclusively for large and very large boats, despite the existing public demand for berthing for small boats as evidenced by the waiting lists for small berths at the other two marinas in San Francisco: South Beach Harbor and the San Francisco Marina Small Craft Harbor. Further, the development of a new entrance channel along the south side of the Cove would do little to facilitate access to Clipper Cove, as current marina residents and transient boaters currently access the Cove though the existing northern channel. In this light, the guidance from the NOAA Programmatic EFH Consultation with USACE For Construction & Maintenance of Overwater Structures is particularly relevant: “Given the significant alteration of existing shoreline and shallow water habitats in some regions of San Francisco Bay, all overwater structures should be water dependent (e.g., could not be constructed over land). Proposed projects should clearly explain their water dependency and why the project is in the public's best interest.” (emphasis added).

NOAA’s California Eelgrass Mitigation Policy and Implementing Guidelines states that: “For all of California, compensatory mitigation should be recommended for the loss of existing eelgrass habitat function, but only after avoidance and minimization of effects to eelgrass have been pursued to the maximum extent practicable.”

Given the significant risk to essential fish habitat, given the lack of adequate environmental analysis, given the lack of public benefit from the project, and per NOAA Eelgrass policy, this project should not be permitted as designed, pending hydrodynamic analysis, to avoid the loss of existing eelgrass habitat.

Thank you for your attention to this issue.

Sincerely,

Arthur Feinstein
Chair, Sierra Club Bay Alive Committee
415-680-0643