MOSAIC MANIA
Our photomosaic program is in full swing! This month, we completed one of our largest mosaics, covering an area of 2,500 square meters at Carysfort Reef, where we plan to outplant staghorn corals next year. We also completed photomosaics for each of our 8 restoration sites at one-month post-outplanting, the most mosaics we’ve ever used to monitor our corals on the reef.
Photomosaics are transforming our restoration strategy. Going forward, our divers will be taking photomosaics of each restoration site before we outplant, giving us a permanent visual record to see the direct impact our corals have on the benthic ecosystem. We will then take a new mosaic at the time of outplanting, with follow-ups after one month and one year. These images provide multiple data points for a specific outplant site over time, clearly documenting the change that occurs as a result of our outplanting.
By monitoring in this way, we can explore new methods of outplanting and dramatically increase the density of our coral coverage. Currently, we outplant our corals in small clusters along transect lines, which divers use to survey the health of each individual coral by hand. This limits where we can plant our coral and small cluster size further limits our outplant capacity.
Photomosaic of Carysfort Reef prior to restoring corals in this area.
Photomosaic monitoring, on the other hand, allows us more flexibility in our outplant design as the corals can be traced in the mosaics and do not rely on in-water tagging of genetically unique clusters. Not only does this give us much more freedom in our outplanting, it shifts the focus of our monitoring from individual coral survivorship to total area of reef restored.
Photomosaics also require less resources than in-water diver surveys. To take a mosaic, one diver swims across a restoration area with two mounted cameras, each taking one photo per second. These photos are then digitally compiled into a single image, providing a high resolution birds-eye-view of every coral. This captures more information in a single dive than a full team of divers could record by hand in an entire day.
As we train our staff on photomosaics, they will eventually replace diver surveys entirely. This will drastically reduce the amount of time spent collecting raw data, and increases the quality of our monitoring over different site substrates, locations, and species. Our new mosaic of Carysfort Reef is the first step into a new practice of restoration that is more flexible, more efficient and more effective.
PILLAR CORALS ON THE RISE AT CRF™
CRF™’s pillar coral stock is growing! Our nursery holds 95 pillar corals across 22 genotypes, many of which have moved to our in-water nursery from our collaborator’s land based facilities. As Stony Coral Tissue Loss Disease (SCTLD) continues to impact pillar corals across the Caribbean, the healthy specimens in our nursery could lay the foundation for the species’ next generation in the keys.
Our science department is responsible for looking after the pillar corals. Two of our interns, Krista and Nik, are tracking the growth of each individual coral over time using digital imaging software. The data we’re collecting will eventually reveal which pillar coral genotypes are most successful in our nursery, as well as the optimal environmental conditions for growing pillar corals quickly. Potentially, this project could lead to a timeline for bringing the species into outplanting production.
We also spend plenty of time cleaning the frags, repairing their coral trees and doing all the necessary housekeeping to make sure our corals stay happy and healthy. This also includes treating any signs of disease with antibiotics to prevent Stony Coral Tissue Loss Disease from getting a foothold in our nursery. We’re very happy to give our pillars all the attention that they need, and are looking forward to unpacking their growth data over the next few weeks. Stay tuned for results!
We’re not the only ones working to save pillar corals; CRF is part of a network of organizations in south Florida dedicated to preserving the species, including the Florida Aquarium, NOAA, Keys Marine Laboratory, Mote Marine Lab and Nova Southeastern University. Dr. Karen Neely, a pillar coral specialist, is one of the driving forces behind this effort. She recently sent out an update on our progress:
“There are over 500 individuals representing over 100 genotypes currently in holding. And that’s not counting the babies that the Florida Aquarium team was amazingly able to produce this year from these rescued individuals. As a result of everyone’s efforts, we have learned so much about how to collect, transport, care for, and propagate this species.”
Overall, we’re thrilled with the success of our collaborators and could not be happier to see our group’s positive impact. The immense dedication that this team has shown is a true ray of hope for the species, and proves that there is still reason to be optimistic for the future of pillar corals in Florida.
BEN YOUNG SHEDS A LIGHT ON CORAL DISEASE
CRF™ was happy to host PhD candidate Ben Young last month for our Sips and Science program. Young, a third year PhD student at the University of Miami, studies the genetics of coral disease, and has been using corals from our nursery to investigate the role of genes in host response to disease transmission.
It’s often difficult to determine the cause of a coral disease because there are so many different organisms living inside of a coral’s tissue. Each polyp is a tiny ecosystem, and contains photosynthetic algae, bacteria, viruses and other symbiotic microorganisms that contribute to the polyp’s health.
When the polyp becomes sick, it’s usually unclear whether the sickness is caused by a new invading pathogen, the loss of a symbiont, or a ‘misbehaving’ symbiont harming the polyp. This is complicated further by differences in the corals themselves; certain corals’ genes help them resist disease, while others make them more vulnerable. All of these factors combined make it very hard to predict how an individual coral will respond to a disease.
Young is disentangling this problem by focusing on the role of genetics in corals affected by White Band Disease, specifically. In 2016, a disease grafting experiment was conducted in which healthy corals of many different genotypes were permanently attached to diseased corals. Researchers tracked which corals contracted the disease and which stayed healthy, in the hopes of determining which coral genotypes might be most successful in the wild. Young took this a step further, analyzing the genetics of each coral sample to determine which individual genes are associated with disease resistance.
Although Young’s results did not show that certain genotypes were substantially more resistant than others, he did find that the expression of certain genes was more common in corals which showed no disease transmission. This indicates that the disease response of the entire coral, including symbiotic organisms and abiotic factors, was more significant than the coral’s genotype. This is a potentially encouraging result, as it indicates that corals of many different genotypes have the tools to resist disease.
Going forward, Young is building on these results by exposing corals to specific disease treatments while controlling abiotic factors in a lab. He and his team are also collecting samples from corals that CRF has outplanted, in the hopes of creating a large database of our corals’ genetic responses to disease events. Ultimately, Ben aims to build a tool that researchers can use to quickly determine whether a coral is vulnerable to disease based on its genotype, significantly improving diagnosis and treatment.
You can read more about Ben Young and his research in our Collaborations feature. Check out upcoming Sips and Science events on our social media.
"Talking Science" Editorial Intern
Nik is a recent graduate of the University of Chicago, where he studied English and environmental science. He grew up in Virginia, and first learned to dive on a family trip to the US Virgin Islands in 2011. During college, he travelled to Bocas Del Toro, Panama to study ocean acidification with the Smithsonian Tropical Research Institute. Nik is very happy to be contributing to the Coral Restoration Foundation™’s important work, and hopes to make a positive impact on the Keys’ marine communities both on land and in the water.