UC San Diego

The Naval Weapons Station Seal Beach is undergoing construction to remove and replace an ammunition pier within the same vicinity as resident Seal Beach green sea turtles. The goal of this study was to determine green turtle movements, habitat use, and core areas of activity throughout the Seal Beach National Wildlife Refuge (SBNWR) and construction area in Anaheim Bay. Research took place prior to the commencement of construction through approximately six months during construction. Sixteen green turtles were equipped with FastLoc GPS-enabled satellite tags and tracked from November 2018 through July 28th, 2020. Volunteer visual data, hourly movements, and home range analyses determined that the majority of green turtle movements were within the inner portions of the SBNWR, although four turtles transitioned into Anaheim Bay, two turtles continued offshore prior to returning to Anaheim Bay and a single individual left the SBNWR and visited Huntington Harbour frequently. Core areas of activity (50% Utilization Distributions; UDs) for three spatial strata (SBNWR and Anaheim Bay combined, offshore, and Anaheim Bay only) were found to be 0.95 km2, 40.95 km2, and 0.27 km2, respectively. Individual 50% UDs within SBNWR ranged from 0.02 km2 to 1.43 km2 (mean ± SE: 0.36 ± 0.11 km2), and 95% UDs ranged from 0.18 km2 and 6.92 km2 (mean ± SE: 1.96 ± 0.57km2). These preliminary baseline results provide information on green turtle movements and core areas of activity in SBNWR, Anaheim Bay, and surrounding waters that will help inform conservation efforts to minimize impacts to green turtles.