People

PhD Candidate

ARC Centre of Excellence for Coral Reef Studies
Building 19, Room 123
James Cook University

Phone: +61 7 4781 3192
Email: justin.rizzari@my.jcu.edu.au

Justin grew up in Texas along the Gulf Coast of Mexico where his interests in the ocean began at an early age when he began surfing and fishing. After trips to the Caribbean and Central America he began to gain a keen interest in tropical marine life. He graduated from Texas A & M in Corpus Christi with a Bachelor of Science in Environmental Science with a concentration on marine and coastal resources. Participating in a research program in tropical marine ecology in the Caribbean and working at a coral lab in the Red Sea solidified his desire to study the marine environment, specifically coral reef associated ecosystems. He then moved to Townsville in 2011 to start a Master of Applied Science at JCU, and studied the effect of reef shark behaviour across different levels of management zones. His current PhD focuses on the effects of predators on coral reef trophic ecology, which is conducted under the supervision of Prof. Mark McCormick, Dr. Ashley Frisch, Dr. Andrew Hoey and Dr. Mark Meekan.

Project Title:

Effects of apex predators on coral reef trophic ecology

Project Description:

Apex predators, such as sharks, are experiencing rapid world-wide declines in coral reef ecosystems. Evidence from terrestrial and oceanic habitats indicate that apex predators often have disproportionate influences on ecosystem components via top-down control of community composition and prey behaviour. At present, our understanding of the ecological role and importance of apex predators on coral reefs is severely limited. Therefore, widespread declines in apex predator populations are of great concern to those who manage marine ecosystems, particularly coral reefs. This project aims to examine the trophic role and importance of apex predators on coral reefs and to what degree fishing disrupts these trophic interactions. This will be accomplished through use of manipulative experiments, diet analyses, stable isotope measurements and population assessments of apex predators and other key functional groups  in fished, un-fished and no-entry zones of the Great Barrier Reef Marine Park. Project findings will identify the importance of apex predators in maintaining coral reef health and assess the effects of declining apex predator populations on the broader ecosystem. It is anticipated that this research will underpin innovative approaches to ecosystem-based management of coral reefs.

Supervisors:

Professor Mark McCormick, Dr. Ashley Frisch, Dr. Andrew Hoey, Dr. Mark Meekan

Publications List:

• Rizzari JR, Frisch AJ, Connolly SR (2014) How robust are estimates of coral reef shark depletion? Biological Conservation. 176: 39-47
• Rizzari JR, Frisch AJ, Hoey AS, McCormick MI (2014) Not worth the risk: apex predators suppress herbivory on coral reefs. Oikos. 1293: 829-836
• Frisch AJ, Cole AJ, Hobbs J-PA, Rizzari JR, Munkres KP (2012) Effects of spearfishing on reef fish populations in a multi-use conservation area. PLoS ONE 7: e51938

Conference Presentations:

• International Coral Reef Symposium (2012) Estimating the abundance of imperiled apex predators: a comparison of census methods across a gradient of human interaction
  

Awards:

2014: Grant from the Save Our Seas Foundation

2013: James Cook University Graduate Research Scheme

2012: James Cook University International Postgraduate Research Scholarship