This study provides the first assessment of demographic and habitat information
for pinto abalone (Haliotis kamtschatkana) in San Diego, California, two decades after
the closure of all abalone fisheries in southern California. SCUBA surveys conducted
from June 2014 to December 2016 indicate that current low densities (0-0.03
individuals/m2) were far below critical thresholds identified for other abalone species
(0.15-0.30 abalone/m2) for successful spawning and recruitment. A broad range of sizes
were represented (13-146 mm), however, only 95 individuals were found. Some sites
showed significant aggregation of adult (> 50 mm) pinto abalone, 30% of adults had a
nearest-neighbor within a critical spawning distance of 2 m, and 65% had a neighbor
within 5 m, indicating that at least a small proportion of individuals may be capable of
reproducing successfully. Pinto abalone showed a significant preference for boulder
habitat at a lower relief (< 10 cm) relative to available habitat– a preference that may
influence aggregation around habitat features and enhance reproduction. The frequency,
timing, and broad spatial distribution of these surveys was not sufficient to measure
patterns in recruitment or changes in abundance, particularly over a strong El Niño event
that occurred during the study period. There is a critical need for consistent long-term
monitoring in southern California to better understand demographic and environmental
processes affecting recovery and persistence of populations, particularly at the southern
edge of the broad range of pinto abalone.