Presidio Marsh

Presidio, San Francisco

Since 2018 professors Margaret Ikeda and Evan Jones have been working in Crissy Marsh in San Francisco’s Presidio to to promote habitats for oysters and other marine organisms in preparation for a new culvert within the marsh. The project represents the final phase of the Doyle Drive redesign of the 101 freeway which includes connecting the Tennessee Hollow Watershed to the marsh and expanding the marsh inland to almost double it’s size. The Presidio Trust sought to tie the ecologies through two new sixty foot long culverts and came to the Architectural Ecologies Lab to look at the potential to increase the available habitat along these new hard edges. Using parametric software, the Architectural Ecologies Lab designed a series of plates which built upon AEL research projects looking at optimized substrates for marine invertebrates  previously tested in Monterey Harbor and the San Francisco Bay, and currently part of the experiments deployed at the Float Lab in Middle Harbor Shoreline Park. Through the creation of diverse habitats along these new walls, an ecological connectivity can be facilitated to the new marshland. In partnership with longtime collaborators, marine biologist at Benthic Lab in Moss landing (John Oliver and Kamille Hammerstrom) and advanced polymer fabricators at Kreysler and Associates (Bill Kreysler and Joshua Zabel) two series of experimental plates were designed to understand the extent of the presence of oysters in the marsh. AEL Research Fellow Sean Cunningham (CCA March ’19) worked throughout the project to adapt these digital workflows to the new plates. The first phase involved the generation of ten variable experimental substrates which comprised the research phase of the project. Variations in this phase included the addition of crushed oyster shells and whole shells onto the surface to study the effect of various surface materials. With consultation and monitoring of Benthic Lab, these floating experiments were deployed into the marsh under floating glass buoys and able to recruit hundreds of oysters within the marsh over the course of nine months. The success of creating oyster habitats on these plates formed the basis of the next phase of the project which involved working closely with the contractors to texture the culvert walls and design attachment ledgers to install the next series of plates. These latest series of plate design, finalized under the specter of the pandemic lockdown, are to be installed into the finished culvert before the official opening of the marsh by early 2021. Four variations were designed which explored variations in surface rugosity, larger peaks and valleys and variable hole surfaces. A total of 32 Plates were constructed at Kreysler and Associates, using CNC routed molds and layers of fiberglass resin. The design of the attachment ledgers allows for the panels to be moved based on the ideal locations of oyster habitats and has ample attachment points for further panel research and explorations of alternate materials.