Giving coral babies a headstart
Three long-spined sea urchins share a mini pool with baby golfball corals growing on the tetrapods. (SECORE International)
Together with their new team of students (Lars ter Horst (University of Amsterdam), Julia van Duijnhoven (Utrecht University) and Jeroen Schneider (Aeres University of Applied Sciences)) Kelly Latijnhouwers and Valerie Chamberland built a new ‘mini-pool-setup’ consisting of 16 small basins that can be mounted inside SECORE’s in-situ larval rearing pool to run replicated experiments. Inside these mini-pools, the team reared baby golfball corals (Favia fragum) settled on SECORE tetrapods within different feeding and grazing treatments.
In some of the mini-pools, juvenile long-spined sea urchins (Diadema antillarum) grazed on the tetrapods to limit the growth of algae that can kill coral settlers, while in other mini-pools, baby corals were fed every other day with nutritious brine shrimps. In case you wonder: scientists in the pictures look a little blue due to the blue-colored cover of the pool.
All the tetrapods with Favia fragum settlers were outplanted to the reef at the end of March. The effect of feeding and co-culturing these settlers with grazing urchins on their growth and survival will be monitored over the course of the next few months. Preliminary results are looking promising!
Fed settlers have already grown to larger sizes than their unfed counterparts. While similar diets have been shown to improve coral growth and health in aquaculture settings before, this is to our knowledge, the first time feeding protocols are implemented within ocean-based nurseries within a restoration context. We are hopeful that will allow them to stay healthy and survive better on the reef.
The baby golfball corals were less than a centimeter in diameter (left) when our team run the experiment in the mini pools (center). A big shoutout to our students, which helped to build the mini pools and took care of the coral babies (right). (SECORE International)
We are very thankful that the team managed to place these corals on the reef just before Curacao went on a full lock-down due to the ongoing COVID-19 pandemic. The team of students has unfortunately been repatriated and could not finish their research projects on the island, but we are very grateful for the time and effort they invested in making this project such a success.