Spatial, temporal, and size-specific variation in mortality estimates of red abalone, Haliotis rufescens, from mark-recapture data in California

Abstract

Estimates of size-specific mortality were made for red abalone, Haliotis rufescens, from mark-recapture data for three size classes at six sites in California. Instantaneous mortality for the smallest size class (≤100 mm) was 0.67 y −1 (0.52–0.84 y −1, mean ± S.E.) to 1.02 y −1 (0.84–1.24 y −1, mean ± S.E.) and decreased with increasing size in both northern and southern California. Mortality was spatially variable for legal size abalone (>178 mm), 0.05 y −1 (0.0–0.14 y −1, mean ± S.E.) to 1.35 y −1 (1.17–1.56 y −1, mean ± S.E.) in northern California and varied temporally in southern California, 0.27 y −1 (0.15–0.42 y −1, mean ± S.E.) to 0.89 y −1 (0.73–1.08 y −1, mean ± S.E.). Estimates of fishing mortality were 0.97 y −1 (±0.21S.E.) and 1.29 y −1 (±0.17S.E.) at two sites in northern California. Understanding the spatial and temporal dynamics of mortality estimates is critical for fishery management and conservation.