Our first batch of 6-month-old Tridacna Gigas arrived on the island 2 1/2 years ago! Celebrating their third birthday, all of our Tridacna Gigas juveniles are now in the ocean and thriving in their natural habitat. Their growth has been excellent since moving to the ocean nursery, but there have also been a few challenges!
As a remedy, we have introduced "clam condos" to the reef. These are small individual cages with very large protective grating. This prevents the larger predators from attacking the clams but still allows them to adapt to their reef ecosystem and lets them live symbiotically with smaller species. All fo these cages are bottomless, so when the timing is right, we hope to simply lift the cages and the adolescent clams will remain in their forever home!
Cylone Sarai presented another problem... This was the first major weather event since the clams have been in the sea. In preparation for the storm, cages were secured and additional concrete slabs were installed to prevent them from overturning. Unfortunately, Sarai’s direction did quite a bit of damage to our reef and the clam cages. None of the cages were overturned, but their contents were severely tumbled. We were able to rescue nearly all of the babies, with only a few casualties caused by the debris. To combat this moving forward, we've installed dividers into some of the cages in the hopes that this helps should we be faced with similar weather conditions. There is quite a bit of trial and error going on here, and together with the Fisheries Department, we are learning a lot!
When the minister of fisheries visited the island he also suggested installing spat collectors to collect data and contribute to the science aspect fo this project.
These collectors are a rope of 300 chaplets that are slightly furry and hang from the buoys outside our dive area. The idea is for these to pick up spawning materials from the various species thriving on Tavarua. While our gigas babies have not reached reproductive maturity, our many adult species have shown signs of regular spawning. These chaplets will pick up larvae from not only our giant clam broodstock, but oysters, sea cucumbers and other bi-valve species. In 4-6 months, we should be able to see what other kinds of species are thriving and reproducing in the reef system surrounding Tavarua!
Meanwhile, back on island... our land hatchery is celebrating our Tracna Derasa's 1 year birthday! These are slow growers, and still being monitored in the on-island nursery, but a very hardy species. With our experience starting to pay off, the success rate has been exceptional!
Stay tuned and vinaka vakalevu for your continued interest and support!