Julie Zill


On heavily fished reefs, fishermen act as top predators in the system, however their prey selectivities differ from that of the natural predator assemblage. I’m interested in whether human preference for some desired fish species over others could lead to the release of untargeted mid-level predators (mesopredators) from top down control – specifically, moray eels. I also seek to understand the impact that such asymmetrical mesopredator release would have on the lower trophic levels of the reef fish community.

I became interested in marine biology while working at a sea turtle rehabilitation center and public aquarium during high school. While an undergraduate at the University of Florida, I took a coral reef ecology field course at the Bermuda Institute of Ocean Sciences and was introduced to scientific diving. In 2010, I did an internship in Brazil documenting the high biodiversity of the remote Rocas Atoll marine reserve with the Federal Rural University of Pernambuco. I then began volunteering in the invertebrate zoology lab of Dr. Gustav Paulay at the Florida Museum of Natural History, and worked with François Michonneau on various research projects involving sea cucumber phylogenetics and the host associations of their molluscan parasites.


I transitioned into the field of coral reef ecology in the lab of Prof. Craig Osenberg, where I assisted graduate students Mike Gil, Anya Brown, Elizabeth Hamman, and Lianne Jacobson with their doctoral research over the course of three summers in Moorea, French Polynesia. The projects in the Osenberg Lab included the behavioral effects of habitat fragmentation on herbivory, the chemically-mediated effects of vermetid snails on coral-algal interactions, the interactive effects of corallivorous snails and sediments on Pocillopora coral, and the density effects of vermetids on coral growth. I also led a multiple-stressors project that examined the context-dependent effects of vermetids and sedimentation on coral growth.

Experimental corals covered by a vermetid net.
Experimental corals covered by a vermetid net.

I entered the Donahue Lab first as a lab technician in 2013 and then as a Marine Biology graduate student in Fall 2014.


J. Zill, M. Gil, & C. Osenberg. (2017). When environmental factors become stressors: interactive effects of vermetid gastropods and sedimentation on corals. Biology Letters 13(3): 20160957



Gil, M., J. Zill, & J.M. Ponciano. (2016). Context‐dependent landscape of fear: algal density elicits risky herbivory in a coral reef. Ecology 98: 534–544. doi:10.1002/ecy.1668


muricidvermetidBrown, A., J. Zill, T. Frazer, & C. Osenberg. (2014). Death and life: Muricid snails consume the vermetid gastropod, Dendropoma maximum, and use empty shells for reproduction. Coral Reefs, 33(2): 497-497.



Atol das Rocas

Batista, H., D. Veras, P. Oliveira, D. Oliveira, M. Tolotti, Y. Marins, J. Zill, R. Pereira, F. Hazin, & M. Silva. (2012). New records of reef fishes (Teleostei: Perciformes) in the Rocas Atoll Biological Reserve, off northeastern Brazil. Check List, 8(3): 584-588.