Coral sexual reproduction
The key reef building corals of the Caribbean reproduce through synchronized mass spawning events and fertilisation takes place in the water column until larval settlement takes place 3-10 days later. In most species, larvae are produced only a few nights per year. During this larval phase mortality is high, and only a small percentage of larvae successfully settle onto reef substrate. This can be a bottleneck to ecosystem recovery, as both the abundance of healthy adult corals and suitable substrate are reduced on degraded coral reefs.
To support natural sexual reproduction in corals, restoration practitioners collect coral gametes (eggs and sperm) from coral colonies in the field, assist them to fertilise in the lab, rear the coral recruits in aquaria through the most vulnerable life stages, and then transplant the baby corals back onto the reef.
Each summer, I coordinate spawning observations and gamete collection as part of the coral sexual reproduction for restoration program of CORALIUM, National Autonomous University of Mexico (UNAM).
In 2016, I trained under Professor Banaszak, who collabroates with Secore International to provide bilingual (Spanish and English) training programs for restoration practitioners from around the Mesoamerican and Caribbean region. The course is a month-long intensive course on coral sexual reproduction at the UNAM in Puerto Morelo and the following year, we initiated coral spawning monitoring in Akumal.
With local stakeholder support from Akumal Dive Center and Hotel Akumal Caribe, we made the first reported observation of coral spawning in Akumal in 2017. I trained local and international divemasters and instructors to observe field spawning and deploy coral spawning nets, and we collected gametes from Acropora palamta at three sites. We brought the gametes back to the Hotel Akumal Caribe, who provided us with a room to conduct assisted fertilisation and rearing of coral larvae. fertilized them in a hotel room.
Akumal's Coral Lab
Thanks to funding from the Coral Conservation Society, we developed Akumal as a new site in the CORALIUM network, and in 2018, granted funds to build an on-site wet lab on the grounds of the hotel to support this work each summer. Akumal’s coral lab has coral rearing bins which are gravity fed by 2 x 1100 litre tanks of UV-filtered water.
The Coral Observer App
Due to the pandemic, I was not able to travel to Akumal in 2020 and 2021; instead, I worked with my friend at quantumweb.co to create www.CoralObserver.com a web-based app designed to streamline data collection for coral spawning observations.
The app is free and easy to use. If you would like to use it for your database or to contribute your data to the datasets being collected in the region to support the science, please try out the app and get in touch with your feedback!