An application of underwater imaging for marine vertebrate ecology

Moss Landing Marine Laboratories (MLML) and the National Marine Fisheries Service have conducted leatherback (Dermochelys coriacea) sea turtle research for the last eight years. Leatherbacks come to the central California coast to forage on concentrations of jellyfish that accumulate in the nutrient rich waters over the coastal shelf. The research includes tracking leatherbacks across the Pacific Ocean with satellite transmitters, suction-cup attachment of time-depth-recorders (TDR) tags, and collection of morphological data. The TDRs are used to record the dive profiles of the leatherbacks foraging for jellyfish near shore. The TDR data provide graphical representation of the dive profile, showing decent and ascent rates, along with variations or deviations in the ascent pattern. This paper describes an application of a modest, but unique underwater imagining system designed and constructed at MLML to answer some of the questions inspired by the dive profiles. MLML's Turtle Cam synchronizes dive profiles with video images, providing researchers with a tool that is giving new insights to leatherback foraging ecology.