Ecological Niche Partitioning Within a Large Predator Guild in a Nutrient&
LIMNOLOGY and Limnol. Oceanogr. 62, 2017, 934–953 OCEANOGRAPHY VC 2017 Association for the Sciences of Limnology and Oceanography doi: 10.1002/lno.10477 Ecological niche partitioning within a large predator guild in a nutrient-limited estuary Philip Matich,1,2* Jerald S. Ault,3 Ross E. Boucek,4 David R. Bryan,3 Kirk R. Gastrich,1 Christine L. Harvey,3 Michael R. Heithaus,1 Jeremy J. Kiszka,1 Valeria Paz,1 Jennifer S. Rehage,4 Adam E. Rosenblatt5 1Marine Sciences Program, Department of Biological Sciences, Florida International University, North Miami, Florida 2Texas Research Institute for Environmental Studies Sam Houston State University, Huntsville, Texas 3Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida 4College of Arts Sciences and Education, Florida International University, Miami, Florida 5School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut Abstract Within oligotrophic ecosystems, resource limitations coupled with interspecific variation in morphology, physiology, and life history traits may lead to niche partitioning among species. How generalist predators parti- tion resources and their mechanisms, however, remain unclear across many ecosystems. We quantified niche partitioning among upper trophic level coastal and estuarine species: American alligators (Alligator mississippien- sis), bull sharks (Carcharhinus leucas), common bottlenose dolphins (Tursiops truncatus), common snook (Centro- pomus undecimalis), and Atlantic tarpon (Megalops atlanticus) in the Shark River Estuary of the Florida Coastal Everglades, USA using acoustic telemetry, stable isotope analysis, and visual surveys, combined with published diet and life history demographic information. Spatial and isotopic niche overlap occurred among most species, with variability in partitioning among interspecific interactions. However, seasonal variability in habitat use, movements patterns, and trophic interactions may promote coexistence within this resource-limited estuary.
[Show full text]