Fine-scale horizontal and vertical movement of barred sand bass, Paralabrax nebulifer, during spawning and non-spawning seasons

Habitat use, ecotone edge response, activity space size and association with seafloor and thermocline were compared for spawning and non-spawning season barred sand bass (Paralabrax nebulifer). Non-spawning season fish showed affinity with sand/reef ecotone using average activity space areas of 0.003 ± 0.001 km2 (±SD) and volumes of 0.00001 ± 0.000005 km3 while remaining 1.9 ± 1.7 m off the seafloor. Spawning season fish used activity space areas of 0.139 ± 0.370 km2 and volumes of 0.001 ± 0.002 km3. Spawning season individuals displayed two patterns of behavior, one indicative of spawning and another of resting behavior. Resting individuals tracked during spawning season behaved similarly to fish tracked during the non-spawning season, using smaller activity space areas while associating with reef structures and the seafloor. Presumed spawning individuals utilized sand habitats, using significantly larger activity spaces during the day than at night while associating with the thermocline and making repeated vertical dives toward the seafloor.