Seasonal shifts in the movement and distribution of green sea turtles Chelonia mydas in response to anthropogenically altered water temperatures

Trace metals in green sea turtles (Chelonia mydas) inhabiting two southern California coastal estuaries

“…Along the western coast of the U. S., the northernmost resident foraging aggregations of green turtles inhabit San Diego Bay (SDB) and the Seal Beach National Wildlife Refuge (SBNWR) (Eguchi et al, 2010;MacDonald et al, 2012;Crear et al, 2016). SDB is home to a major U.S. Navy base and subject to other anthropogenic activities such as ship maintenance, dredging, fishing, and boating, which have resulted in the bay being listed (303D) as an impacted body of water (Fairey et al, 1998).…”

“…SDB is home to a major U.S. Navy base and subject to other anthropogenic activities such as ship maintenance, dredging, fishing, and boating, which have resulted in the bay being listed (303D) as an impacted body of water (Fairey et al, 1998). SBNWR is located within a naval weapons station and green turtles have been shown to forage in the surrounding area (Crear et al, 2016;Crear et al, 2017). The SBNWR is within 15 km of the Port of Los Angeles, has a naval weapons station, and has input from many impacted waterways and water bodies influenced by industrial and residential runoff (Schiff et al, 2011;Dodder et al, 2016).…”

“…Previous studies on green turtles have shown that SDB green turtles bioaccumulate anthropogenic contaminants such as trace metals (Komoroske et al, 2011). However, the green turtle aggregation in the SBNWR was only recently discovered as a permanent foraging aggregation and has not been previously studied for trace metals accumulation levels (Crear et al, 2016). Considering the different sediment trace metal profiles (Dodder et al, 2016), the high site fidelity green turtles exhibit (Eguchi et al, 2010;Crear et al, 2016), and previous research demonstrating green turtle trace metal bioaccumulation from urbanized habitats (Komoroske et al, 2011), we hypothesized that green turtles from the SBNWR and SDB would have location-based differences in trace metal bioaccumulation.…”

“…However, the green turtle aggregation in the SBNWR was only recently discovered as a permanent foraging aggregation and has not been previously studied for trace metals accumulation levels (Crear et al, 2016). Considering the different sediment trace metal profiles (Dodder et al, 2016), the high site fidelity green turtles exhibit (Eguchi et al, 2010;Crear et al, 2016), and previous research demonstrating green turtle trace metal bioaccumulation from urbanized habitats (Komoroske et al, 2011), we hypothesized that green turtles from the SBNWR and SDB would have location-based differences in trace metal bioaccumulation. By assessing trace metal concentrations in both aggregations we can: (1) determine whether there are differences in trace metal concentrations between sampling locations, (2) assess if trace metal concentrations have changed since previous studies in SDB green turtles, and (3) compare SBNWR and SDB turtle trace metal concentrations with those found in previous research around the world.…”

Finding Crush: Environmental DNA Analysis as a Tool for Tracking the Green Sea Turtle Chelonia mydas in a Marine Estuary

“…This is a local resident population that historically represents the northernmost sizable foraging population for C. mydas in the Northeast Pacific, consisting primarily of the Revillagigedo Islands and Michoacán breeding populations in Mexico (Dutton et al, 2019). In the past, C. mydas has been largely absent or rare in coastal waters along the US West coast, but the species appears to be increasingly present at foraging areas north of their historic range in Baja California, Mexico and the US Border region of San Diego (Crear et al, 2016;Crear et al, 2017;Dutton et al, 2019;personal observation). This change in distribution has created a need to incorporate the detection of C. mydas into habitat surveys in ways that were previously not considered.…”