Area use and movements of the white croaker (Genyonemus lineatus) in the Los Angeles and Long Beach Harbors

• White croaker were tracked within the Los Angeles and Long Beach Harbors using both active and passive acoustic telemetry.
• Movement patterns varied significantly among different regions of the Harbors.
• Long-term dispersal of white croaker throughout the Harbors was not random.
• Movement between regions of the Harbors was directional and intentional.
• Emigration of white croaker from the Harbors to the PV Shelf was rare.

Understanding the movements of fish in relation to areas of contaminated and urbanized habitats is crucial to fisheries management and habitat remediation. In this study, the movements of white croaker in the Los Angeles and Long Beach Harbors were examined using both active and passive acoustic telemetry tracking. Daily area use for 20 fish actively tracked over multiple days averaged 94,720 ± 78,720 m2 (±SD), with daily activity spaces shifting over periods of up to 1 month. Long-term dispersal (up to 7 months) of 93 passively tracked white croaker followed significantly non-random patterns, with 55 individuals (59.1%) making inter-regional Harbor movements. Inter-regional movements took an average of 4.7 ± 4.1 weeks to complete. Dispersal was significantly faster than what was predicted by an individual-based random walk model generated from short-term white croaker movements recorded during active tracking within the Harbor. Longer-term dispersal is likely the result of intentional movements between patches of favorable habitat rather than random daily shifts in activity spaces, indicating that white croaker deliberately utilize different areas within the Harbor and over the course of a year utilize much of the favorable Harbor habitat.