This Moonshot for Coral Breeding Was Successful

A woman wearing a polo neck with a logo on it hugs a cooler at an airport. She let out a short laugh. It's relief. There are 10 plastic bottles in the container. They are shaped like cornflakes and are similar to the coral reef of the Florida Keys and the Caribbean.

O'Neil drives back to the Florida Aquarium in Tampa, where she works as a senior coral scientist, after keeping the larvae inside their insulated cooler for 27 C. The beginning of those branching, antler-like shapes that define this species is when the larvae begin their transformation from free- swimming specks into settled polyps. The coral needs warm water with a gentle flow, a soft glow of sunlight, and some ceramic squares that act as landing pads to begin its life.

The last step in a coral breeding project that began on the shores of Curaao, an island off the coast of Venezuela, in the summer of 2018, involved a group of scientists who specialize in one specific stage of coral development. Every step had to go swimmingly for the project to have any chance of succeeding. Kristen Marhaver, a coral scientist at the Caribbean Research and Management of Biodiversity Foundation in Curaao, helped start the relay race by collecting eggs during a nighttime dive at a reef that's 45 minutes away. A second team of scientists at the Mote Marine Laboratory and Aquarium in Florida received their own after O'Neil picked up her coral "babies" in Miami. Both labs were under a lot of pressure. The baton should be dropped just before the final straight.

Hundreds of larvae settled as translucent and fragile blobs of tissue and then began to divide, branching into the clear waters of their shallow, open-top tanks. The average size of the elkhorn coral is 5 to 10 centimeters. The colonies had to be separated and moved over the course of the next year. She says that they almost ended up with a six-foot-by-four-foot solid piece of elkhorn coral. They were growing too much.

There are rows of coral in O'Neil's tank. The Florida Keys used to have a lot of elkhorn coral. Visiting these islands that curl southward from Florida like the tip of a bird of prey's beak, Rachel Carson peered into the shallows using a "water glass" She was able to see a forest of coral through the portal. Over 95 percent of the state's elkhorn coral has been lost after decades of disease. This population is impoverished from within like a forest that has been felled. Some of the reefs in the Keys descend from a single individual that has reproduced and started a new colony. This mode of reproduction allows corals to spread, but without the genetic mixing that comes with sex, these clones are more vulnerable to diseases. The coral that O'Neil raises at the Florida Aquarium are different, they are the result of sperm and egg, a shuffling of genes, and the growth of genetically unique clumps of coral. A boost to the coral's genetic diversity could be provided by re-introduction. Their return could spell disaster.

A map of an atypical origin is hidden inside the genetic code of the Florida Aquarium. The coral populations wouldn't breed in the wild. It is impossible for a sperm to travel hundreds of kilometers between the two. The coral housed in the Florida Aquarium are the product of human hands, the latest addition to a recent trend in conservativism known as "assisted gene flow."

Mary Hagedorn, who is based at the University of Hawai'i at Mnoa, has offered more help to the coral than any other person. Hagedorn traveled to the Caribbean to help with the project. This work is possible due to her research. She has developed techniques that can keep coral sperm fertile after they are frozen. The last few years have seen the use of Hagedorn's techniques for coral sperm in other groups. Tom Moore, a coral restoration manager at the time of this project and now in the private sector, says Hagedorn's work has matured into a solid science at a time when these methodologies are most needed. We are going to see a lot more of this in the next few years.

Without the option to freeze sperm, coral Conservators have been forced to work quickly. In Florida, scientists from the Lower Keys would drive north to meet colleagues from the Upper Keys and exchange sperm samples on the side of the road. Liquid nitrogen can be used to freeze sperm and it can be transported long distances. When eggs are collected from the reef, the sperm can be frozen and used for fertilization. Just a few years ago, Hagedorn's work was mostly ignored.

Hagedorn was self-funded for a long time. Funding didn't seem to see the potential of her work after her savings ran out She was about to close her lab. The Roddenberry Foundation was established in memory of Gene Roddenberry, the writer of Star Trek. The foundation wanted to fund Hagedorn's research for five years because of her work. Since then, her work has grown to include frozen coral, and it has been adopted by labs around the world. Hagedorn runs workshops and shares her techniques freely, and the instructions to build her equipment can be downloaded and made with a 3D printer.

Coral fertilization isn't a perfect science. Hagedorn and her colleagues found that fertilization rates from frozen coral sperm are half the rate of fresh sperm. The coral that lived on the same reef was used to make the figures. It was not known if populations that had been isolated for thousands of years could produce viable offspring, especially after their sperm had been frozen. The most extreme test of Hagedorn's methods was the idea to breed coral from the Florida Keys with coral from the other side of the world. It was a project to conserve coral. It was something that had never been done before.

They had a small chance of success. She didn't think about the hundreds of healthy coral sitting in tanks. They are more aware of the danger. It is not familiar territory to have a moonshot success. Not everyone is comfortable with the idea of moving from the lab to the ocean.

The first rule of restoring ailing ecosystems is to do no harm. The organization that decides the fate of the Florida-Curaao coral is worried that they aren't suited to the local conditions of the Florida Keys. The islands are formed from volcanic activity. The Florida Keys have their own unique combination of problems, from hurricanes to coral bleaching. There are a lot of issues here. It is likely that the corals that are still alive in Florida are the ones that are best suited to living in Florida and providing offspring that are capable of surviving there. Lower rates of reproduction, shorter life spans, or lowered resistance to local diseases might be caused by the introduction of Curaao genes. Depression caused by outbreeding can cause a population to weaken over time. It is possible to introduce genes that haven't experienced the same history.

It is thought that the risk of outbreeding depression is very low. Iliana Baums, head of marine protection and restoration at the University of Oldenburg, Germany, says she is not worried about the impact of the Curaaogenes on the native Florida population. My knowledge of the literature for other species is what leads to that. I don't have any proof of that. The very thing that is controversial and potentially dangerous is the only way to understand it.

O'Neil, Marhaver, Hagedorn, and their colleagues were clear from the beginning of this project that they wanted to work together. They knew that they wouldn't be able to out plant the coral. It wasn't in doubt. She says that the FWC is the most neighborly when it comes to coral reef preservation. I think the nearest neighbor would be Cuba. Mexico or the Bahamas are acceptable places for corals to come from. It's far away from Florida if you have corals from Curaao.

Hagedorn has been researching for almost two decades, but she is tired of waiting. She believes that a large population of captive coral should be introduced given the critical status of A. palmata. She says that there is a joke about the lack of coral in Florida. Scientists have tried to find evidence that new, sexually produced elkhorn coral are in the area, but they often come back empty-handed. The lack of natural recruitment is a sign that mass spawning events are failing. Warmer waters, pollution, a thick covering of algae, and the rarity of mature coral make it hard for baby coral to settle. Sexual reproduction is so low that it doesn't support the population anymore. Sexual reproduction isn't working so we lose more coral every year. We didn't think these coral populations would die out so quickly. I think we need to try something new and I don't think anyone could have wrapped their heads around that 10 years ago.

There is still time to try a less extreme version of assisted genes. The success of the Florida-Curaao experiment has allowed her team to consider crossing coral from Mexico, the Bahamas, or Cuba with Florida stock. The planktonic larvae can travel the current from the Bahamas to Florida so they are considered part of the same subpopulation. She supports any restoration project that complies with the FWC's policy. It will be limited to laboratories and aquariums until then.

O'Neil said goodbye to the coral in December of 2021. They were going to join the rest of the coral grown as part of the study when they were transported from the Florida Aquarium. Some people are being exposed to warmer temperatures in order to see if they can survive in the warmer waters predicted for the future. They will be taken to museums and aquariums in the US. The rest sit and watch as they divide and grow. Their existence opens a wide-angle vista for coral preservation. Anything is possible if the populations can be crossed and grown by the hundred. The coral babies that O'Neil collects from the airport will travel a short distance in their cooler.

Hakai Magazine is an online publication about science and society in the ocean. There are more stories like this at ha Kai Magazine.

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