Spatial distribution of submerged aquatic vegetation in the Shark River Estuary and implications for understanding movement and feeding patterns of manatees (Trichechus manatus latirostris)

摘要

The purposes of this study were to 1) characterize the distribution of submerged aquatic vegetation (SAV) in the Shark River Estuary, 2) determine water quality parameters driving distribution of SAV, 3) document the stable isotopic and elemental content of potential food sources for manatees, and 4) explore the utility of natural variability in isotope ratios of SAV in determining feeding patterns of manatees using isotopic compositions of manatee hairs as analytical tools. The marine/freshwater interface of the estuary was found to be the main factor driving SAV distribution. δ13C of manatee hairs showed significant differences between captive (mean = -24%) and wild (-15.7%) manatees. These results show that manatee hairs reflect the isotopic compositions of their food sources. This provides researchers with the ability to explore manatee travel routes and food consumption habits across a broad spatial range using non-invasive techniques.