To Whom It May Concern:

It has been brought to my attention that the Port of San Francisco proposes to construct a  bridge across Islais Creek at the south end of Illinois St.  The National Oceanic and Atmospheric Administration (NOAA) has recently provided funding to aid in the establishment of the Muwekma Ohlone Sanctuary, adjacent to the

proposed bridge site.

NOAA‚s investment in the sanctuary is aimed to enhance marine habitat, and establish a learning area for schoolchildren and community members.  As a Restoration Ecologist responsible for managing NOAA‚s local restoration grants, I am concerned that the Illinois Street bridge construction and resulting traffic will

negatively impact the educational and biological resources of the Muwekma Ohlone Sanctuary.

Specifically, the proposed project will involve pile driving, which mobilizes large amounts of sediment.  This sediment has the potential to cover valuable (and rare) hard bottom habitat required by many Bay organisms.  In addition, underwater vibrations associated with pile driving can burst swim bladders of area fish, causing significant mortality. During a biological inventory of the Muwekma Ohlone Sanctuary, the native oyster, Ostrea lurida, was found to inhabit the intertidal zone at the site.  This native oyster was once thought to be extirpated from San Francisco Bay, but remnant populations were discovered in 1999.  Because major efforts are underway to restore this once abundant native oyster to the Bay, it would be counter productive to cover the remaining hard bottom areas, where the oysters naturally occur, with sediment. Furthermore, several other intertidal species uncommon in San Francisco Bay were found at the Muwekma Ohlone Sanctuary, suggesting that the intertidal habitat at the site is an important biological resource for the conservation of Bay species.

In addition, NOAA‚s investment in the Muwekma Ohlone Sanctuary involves the establishment of an outdoor education area for local school children and community members interested in Bay ecology.  Increased truck and train traffic on Illinois Street, directly adjacent to the established Sanctuary, will make it difficult for these people to learn at the site.  The Sanctuary will become less accessible due to this increased traffic, and inevitable rerouting of the existing park entrance.

I encourage the Port of San Francisco‚s decision making committee to consider the above factors before approving the Illinois Street bridge project.  If the project is approved, mitigation should include the donation of adjacent Port of San Francisco land to expand the existing Muwekma Ohlone Sanctuary. These Sanctuaries are rare in San Francisco Bay, and represent a valuable education and biological resource that, in its rarity, should be preserved.

Please keep me informed of all activities related to the Illinois Street Bridge project, and feel free to contact me if you have any questions.


Leah Mahan

Restoration Ecologist

NOAA Community Based Restoration Program

777 Sonoma Ave.

Santa Rosa, CA 95404