Understanding the impacts of a mass mortality event of the long-spined sea urchin 
Diadema antillarum
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This project investigates the molecular and physiological response of sea urchins during a recent, extensive die-off of Diadema antillarum that occurred beginning in Spring 2022. This work is funded through an NSF Postdoctoral Research Fellowship in Biology (PRFB), Broadening Participation of Groups Under-represented in Biology, and is conducted in collaboration with researchers at Sociedad Ambiente Marino (SAM) and the University of Puerto Rico Río Piedras.

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The Problem

Coral reefs provide numerous ecosystem services. Within Caribbean coral reefs, the sea urchin Diadema antillarum plays a vital ecological role as an herbivore that feeds on macroalgae that can otherwise overgrow and outcompete the coral. In the early 1980s an extensive mass mortality event dramatically depleted populations of D. antillarum, leading to a shift from coral- to algae-dominated reefs. Unfortunately, similar mass mortalities of D. antillarum began being reported in February 2022 from the US Virgin Islands. Although the causative agent has yet to be identified, incidences of sick and dying D. antillarum have continued to spread throughout the Caribbean, reaching Puerto Rico by April. Affected urchins exhibit loss of movement, spines, and tissues followed by mortality. I am investigating the molecular, organismal, and ecological outcomes of this current die-off event. See the Diadema Response Network for more information about the mass mortality.

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The Goal

Using Diadema antillarum, this project aims to investigate mechanisms underlying environment-to-epigenetic changes and their role in ecosystem function and resilience. The project objectives include: 

  1. Assembling a draft genome for D. antillarum

  2. Assessing existing environmental and biological variability in coral reefs in Puerto Rico

  3. Determining how the prospective pathogen influences epigenetic marks and physiology of unaffected, sick, and recovering D. antillarum

  4. Assessing the epigenetic and genetic diversity of the individuals that remain after the die-off event

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Broadening Participation

Planned activities associated with this project include educational outreach events with students at the Marine Academy of Science and Technology at FIU's Biscayne Bay Campus. Public outreach will also be performed in Puerto Rico with Sociedad Ambiente Marino. This project also supports mentorship in research and professional development to undergraduate and graduate students. You can check out more information about the work done by REU student, Jesse Margolies here.