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Seagrasses in the Age of Sea Turtle Conservation and Shark Overfishing
Frontiers in Marine Science
  • Michael Heithaus, Florida International University
  • Teresa Alcoverro, Centre d'Estudis Avançats de Blanes (CSIC); Nature Conservation Foundation, Karnataka, India
  • Rohan Arthur, Nature Conservation Foundation, Karnataka, India
  • Derek A. Burkholder, Florida International University
  • Kathryn A. Coates, Government of Bermuda
  • Marjolijn J. A. Christianen, Radboud University Nijmegen
  • Nachiket Kelkar, Nature Conservation Foundation, Karnataka, India
  • Sarah A. Manuel, Government of Bermuda
  • Aaron Wirsing, Florida International University
  • W. Judson Kenworthy, NOAA Center for Coastal Fisheries
  • James W. Fourqurean, Florida International University
Document Type
Publication Date
  • Overgrazing,
  • Top-Down Control,
  • Conservation,
  • Marine Protected Areas,
  • Sharks,
  • Sea Turtles

Efforts to conserve globally declining herbivorous green sea turtles have resulted in promising growth of some populations. These trends could significantly impact critical ecosystem services provided by seagrass meadows on which turtles feed. Expanding turtle populations could improve seagrass ecosystem health by removing seagrass biomass and preventing of the formation of sediment anoxia. However, overfishing of large sharks, the primary green turtle predators, could facilitate turtle populations growing beyond historical sizes and trigger detrimental ecosystem impacts mirroring those on land when top predators were extirpated. Experimental data from multiple ocean basins suggest that increasing turtle populations can negatively impact seagrasses, including triggering virtual ecosystem collapse. Impacts of large turtle populations on seagrasses are reduced in the presence of intact shark populations. Healthy populations of sharks and turtles, therefore, are likely vital to restoring or maintaining seagrass ecosystem structure, function, and their value in supporting fisheries and as a carbon sink.

Citation Information
Michael Heithaus, Teresa Alcoverro, Rohan Arthur, Derek A. Burkholder, et al.. "Seagrasses in the Age of Sea Turtle Conservation and Shark Overfishing" Frontiers in Marine Science (2014)
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