| Caltrans increased the drainage capacity and length of a stormwater outfall within the tidal area of Crissy Beach in the Presidio, San Francisco, California during the summer of 2015. As a provision of the National Parks Service special use permit, Crissy Beach was monitored for California grunion (Leuresthes tenuis). Grunion runs in Southern California are well documented but are considered rare in Northern California. Presence of grunion at Crissy Beach was undetermined prior to 2015 monitoring efforts, but suspected by the California Department of Fish and Wildlife. Monitoring at Crissy Beach was conducted by AECOM biologists at night, during peak high tides at full and new moons in June and July. Biological monitors recorded the number of individuals (10 - 1000), size, location, and timing of each spawning event. Grunion spawning was observed 13 out of 16 survey nights. The turbidity curtain deployed around the project footprint had an unintended secondary use as a grunion exclusion device. Biologists and construction personnel worked closely to ensure the outfall was completed on schedule while ensuring grunion spawning areas were protected. This project presented a rare opportunity to document grunion spawning in the San Francisco Bay. |