Matthew Costa ’11


Ecology and Evolutionary Biology

Project Title

Lunar Periodicity and Reproductive Ecology of the Coral Porites Astreoides

Presentation Link

View Matthew's Presentation

I was one of two PEI interns in the lab of Dr. Samantha de Putron, a coral ecologist at the Bermuda Institute of Ocean Sciences.  I worked with Julia Lawson, a returning intern in the de Putron lab from Dalhousie University, on a project focused on the lunar timing of the reproduction of Porites astreoides, a reef-building coral native to Bermuda.  We collected adult colonies from two hand-picked sites, where the reef is exposed to very different light and sedimentation levels.  Over two lunar cycles in July and August, we observed the reproductive cycle of these colonies by counting the number of larvae released by each colony each night.  We sought to discover relationships between several variables and the lunar timing of release, including the size of the larvae, the size and growth rates of spat (the new coral polyps into which the larvae develop), and the density in the larvae of zooxanthellae (the photosynthesizing, single-celled symbionts that allow coral to derive energy from sunlight).

A major focus of our experiment was to study differences in the reproductive strategies of corals from reefs subjected to different sets of conditions, to gain insight into the potential for coral reefs to adapt to the increasingly changing ocean ecosystem.  Dr. de Putron plans on incorporating our results into a paper to be submitted for publication.  In addition to the chance to work on such a fascinating research topic, this internship has granted me the opportunity to explore the beautiful island of Bermuda, to learn to SCUBA dive, and to live and work in the unique and exciting intellectual community at BIOS.

Internship Year


Project Category



Bermuda Institute of Ocean Sciences (BIOS), Bermuda


Dr. Samantha de Putron, BIOS