Relative Abundance, Temporal Patterns, and Growth of Sea Turtles at the Mansfield Channel, Texas

Abstract

Species composition, relative abundance, residency, seasonality, size classes, and growth of sea turtles at the Mansfield Channel, Texas were investigated from 1989-1992. Forty-three juvenile green turtles (Chelonia mydas) (N = 72 captures) and one juvenile hawksbill turtle (Eretmochelys imbricata) (N = 1 capture) were netted during 435 hours of year-round effort (1.38 turtles/km-h). Eighteen of the green turtles (42%) netted were subsequently recaptured, with a mean interval from first to last capture of 120 days (range 22-478 days). However, few of the individuals initially netted between September and February or measuring more than 35 cm straight-line carapace length at initial capture were recaptured. Collectively, green turtles were caught during all months except January. Catch-per-unit-effort was pos- itively correlated with water temperature, air temperature, and water salinity and most green turtles were captured during early morning and late afternoon hours. The Mansfield Channel may provide foraging and resting habitat for both itinerant and seasonally resident green turtles. Juvenile Kemp's ridley (Lepidochelys kempi), green (Chelonia mydas), and loggerhead (Caretta caretta) sea turtles are found within inshore wa- ters of New York, Virginia, and Florida, areas which may serve as important developmental habitats (Mendonca and Ehrhart, 1982; Lutca- vage and Musick, 1985; Byles, 1988; Withering- ton and Ehrhart, 1989; Burke and Standora,