Updated: Aug 6, 2020
This new study will include spawning data from the youngest staghorn outplants ever observed to reach sexual maturity.
This week Coral Restoration Foundation™ (CRF™) will be sending teams out to collect important data on coral spawning synchronization – a little-understood phenomenon.
The team will be looking at ways that genetic make-up and location may influence the timing of release of eggs and sperm (gametes) during a spawning event.
CRF™ has confirmed the presence of gametes in their staghorn outplants from 2018-19 at North Dry Rocks (NDR).
At just 15 months old, some of these staghorn corals are the youngest CRF™ coral outplants ever observed to reach sexual maturity.
Joining CRF™ will be South-East Zoo Alliance for Reproduction and Conservation (SEZARC) who will be collecting gametes for cryopreservation.
Staghorn polyps just seconds after releasing gamete bundles. © Dan Burdeno/Coral Restoration Foundation™
Corals are broadcast spawners, they release their gametes in a synchronized event. Along Florida’s Coral Reef, Acroporid corals normally release their gametes around one week after the August full moon. Synchronization is a critical aspect of the success of a spawning event; it ensures that there are plentiful eggs in the water column and sperm to fertilize them. Spawning is how corals create new, genetically unique, individuals.
Spawning is an energy intensive activity, and so when outplanted corals spawn it’s good news for restoration efforts – it means that these corals are thriving. Coral Restoration Foundation™, has now confirmed the presence of gametes in staghorn outplants at North Dry Rocks going into the 2020 spawning season.
Staghorn corals spawning in Tavernier Nursery © Alex Neufeld/Coral Restoration Foundation™
Over the next two weeks, CRF™ will be studying corals across 25 genotypes in both the nursery and on the reef to analyze the timing of their gamete release. This data will provide important insights into spawning synchronicity across genotypes and locations. Amelia Moura, CRF™ Science Program Manager explains:
"Broadcast spawning relies heavily on a species's ability to synchronize the release of gametes across colonies. This means that corals not only need to sync up their spawning on the same night, but also at the same time of night. A breakdown in spawning synchrony would lead to fewer genotypes in the mix as the gametes meet and fertilize on any given spawning night. Ultimately, preserving the genetic diversity of the staghorn population in the Florida Keys depends on keeping as many genotypes in the mix as possible."
Amelia Moura preparing coral colonies in one of our Coral Nurseries. © Dan Burdeno/Coral Restoration Foundation™
Moura continues, "This year, we want to get a better understanding of how timing might be impacting the larger reproductive success or failure of restored corals. We are going to be comparing identical genotypes on the reef and in the nursery to uncover any differences between spawning in these two environments.”
In the Field
Coral Restoration Foundation™ will be sending two boats out every night, one to the Tavernier Nursery and one to North Dry Rocks (NDR) - one of the organization’s most established outplanting sites.
In the Tavernier Nursery, the CRF™ team has set up “Spawning Alley”. Broodstock corals have been moved to special structures where they can be easily monitored and where nets can be staged for gamete collection.
Divers preparing colonies in Spawning Alley in Tavernier Nursery. © Dan Burdeno/Coral Restoration Foundation™
South-East Zoo Alliance for Reproduction and Conservation (SEZARC) will be joining the CRF™ team in the nursery to start the cryopreservation process as soon as gametes are collected each night. Cryopreservation is the immediate freezing of the gametes. It means that the gametes can later be thawed and used to create new coral genotypes. Preserving these gametes is important for maintaining a genetic bank of these endangered animals. CRF™ has been working with SEZARC and the Florida Aquarium since 2015 to preserve coral gametes and create new coral recruits.
At the North Dry Rocks restoration site, divers will be watching and taking notes on individual outplanted clusters of the same genotypes that are being watched in the nursery.
Staghorn polyps in the "setting" stage as they prepare to release their gametes. © Alex Neufeld/Coral Restoration Foundation™
A New Record for Coral Outplants
Some of the corals in this study group were returned to the reef as recently as May of 2019. At just 15 months old, these are the youngest CRF™ staghorn outplants ever observed to reach sexual maturity. CRF™ Restoration Program Manager, Jessica Levy, explains why this matters:
“That we are seeing corals reach sexual maturity in such a short period of time is incredibly exciting. It means that the corals we are working with are robust and healthy and these natural processes of reef recovery are kicking in almost immediately – it shows that our methods are working.”
The team expects to see spawning action during the nights of August 6th-12th. This year is predicted to be a split spawn for Acroporids (staghorn and elkhorn), which happens when the August full moon occurs very early in the month. Some corals may spawn after the August full moon, and some may spawn after the full moon in early September. While this often presents challenges for researchers, 2018 also saw a split spawning event and it resulted in one of CRF’s most successful spawning events.
Scientist observing Staghorn corals spawning in Tavernier Nursery. © Alex Neufeld/Coral Restoration Foundation™
We’re going to be sharing photos and videos from our boats, and you won’t want to miss out on any of the action! To keep up with the latest developments in our 2020 spawning saga, follow us on Facebook, Instagram, Twitter, and subscribe to our weekly e-newsletter!