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• 2021 Annual Report - In the Spotlight - Helping Corals Survive in a Brave New World

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From 2009–2018, the world’s coral reefs lost 14% of their coral—a blow to fisheries that depend on coral reef habitats, coastal communities that need corals’ protection from storm waves, and economies supported by coral reefs’ services worth $2.7 trillion per year worldwide. These losses add up to more coral than you can find on Australia’s reefs today.

Fortunately, Mote Marine Laboratory’s response with coral research and restoration are adding up too.

Mote scientists restored more than 32,000 corals this year to Florida’s Coral Reef, the highest annual total in Mote’s 13 years of science-based restoration, with primary operations at our Elizabeth Moore International Center for Coral Reef Research & Restoration (IC2R3) on Summerland Key, Florida. Just as exciting: Mote scientists sampled 229 staghorn corals at three of our restoration sites and found that nearly 90% were sexually mature. That means they’re capable of spawning, initiating sexual reproduction to produce coral babies with fresh genetics to help revive imperiled populations.

Of course, this is no time to break out the champagne. The threats of increasing ocean temperatures, ocean acidification, coral disease, pollution and more continue to devastate many coral populations so severely that scientists are scrambling to collect and preserve samples of precious, native genetic varieties that could otherwise be lost forever. To that end, Mote’s new International Coral Gene Bank accepted its first corals this year—providing a secure, inland, “Noah’s Ark” for 1,650 corals of 14 species. Mote currently has nearly 2,000 genotypes of corals, the largest collection outside of Mother Nature herself.

Achievements like these are only possible because of Mote’s groundbreaking science. We’re spearheading efforts to understand and seek new treatments for the deadly stony coral tissue loss disease that has devastated many Floridian and Caribbean corals; we’re providing hard evidence that some corals are genetically resilient to environmental stress, while striving to breed this resilience in the native corals we restore; and we’re investigating and applying the coral restoration methods that work best—because our imperiled coral reef ecosystems deserve our very best.

SCIENCE

Here is a sample of results from Mote science this year:

• Some staghorn corals are genetically hardwired to tolerate climate change impacts (increased temperature and ocean acidification) better than others, and they can likely pass this advantage to their babies, according to a Mote-led study published this year in Proceedings of the Royal Society B. These climate-resilient, native coral genotypes (genetic varieties) are being grown in Mote’s coral nurseries and are valuable for helping reef restoration succeed in our changing climate. Mote scientists exposed the corals to increased temperatures, increased carbon dioxide (the driver of ocean acidification), both stressors together, or seawater with neither stressor, and they collected data to check for changes in 12 traits of coral physiology. As a group, the corals experienced the worst impacts to their physiology when both temperature and carbon dioxide were elevated—a finding that portends trouble for wild staghorn corals that will bear the brunt of climate change. However, many traits varied among the coral genotypes, suggesting the population hosts diverse levels of resistance to stressors and several traits showed high levels of heritability. Excitingly, the corals in this study didn’t suffer any significant tradeoffs (having climate resilience but losing other beneficial traits), which indicates corals could be robust to multiple stressors without physiological disadvantages.
   
• Ocean acidification, a component of climate change, could boost the growth of sponges that can compete with corals, reported a Mote-led laboratory study published this year in the peer-reviewed Journal of Marine Science and Engineering. The study, titled “Ocean Acidification and Direct Interactions Affect Coral, Macroalga, and Sponge Growth in the Florida Keys,” tested how corals, algae and sponges grew when paired with each other or alone, under forecast levels of increased carbon dioxide—a driver of ocean acidification—vs. present day carbon dioxide. The sponges (a species called Pione lampa) grew significantly more amid the increased carbon dioxide. The algae (brown algae species Dictyota) declined slightly when grown alone or with coral, but it grew when paired with sponges. This might indicate that the water had limited nutrients, which the sponges supplied to the algae. In this 28-day experiment, the acidified water didn’t significantly change the growth of corals (lesser starlet corals, Siderastrea radians)—however, a growing body of research does suggest that many coral species will decline over time with ocean acidification, which can impede the formation of coral skeletons. By showing that sponges benefited from increased carbon dioxide, and algae may benefit from the sponges, this project supports a growing notion in the scientific community: that future reefs could be dominated by sponges and algae as corals decline. This study is one of relatively few to explore how ocean acidification could affect not just individual species, but also, the complex interactions between species that shape coral reefs.

• The deadly stony coral tissue loss disease (SCTLD) is worse in areas with higher coral species diversity, more coral cover, and greater numbers of certain coral species (boulder brain corals, mountainous star corals and great star corals). These are just a few of the discoveries reported this year in Mote’s peer-reviewed paper “Fine Scale Temporal and Spatial Dynamics of the Stony Coral Tissue Loss Disease Outbreak Within the Lower Florida Keys,” in Frontiers in Marine Science.
  
  The study reinforced earlier Mote findings that SCTLD spreads contagiously, but it changed our understanding of how water temperature relates to SCTLD. There were fewer cases of the disease when the environment had been hotter for longer periods—different from the pattern seen in many coral diseases that worsen in warmer months. Study findings could support better use of future treatments developed for SCTLD—which affects Florida and Caribbean reefs and is arguably the largest and deadliest coral disease ever recorded—by helping point out which corals are more vulnerable and what time of year they tend to be more vulnerable.

• Mote scientists led a study describing the microbiomes of corals with SCTLD that was featured in a special issue of Microorganisms: "Microorganisms and Wildlife Conservation in the Face of Climate Change." In this collaboration with FWC and NOAA/University of Miami, three tissue types were collected per coral species: lesion (DL) and unaffected tissue (DU) of diseased colonies, and tissue (AH) of apparently healthy colonies. Their findings showed that, for each of the five species under investigation, the microbial community compositions of AH and DU tissues were similar. Furthermore, these two tissue types differed from DL tissue. Bacterial orders Rhodobacterales and Clostridiales were present at relatively high abundances in the DL tissue of four and three species, respectively. For more information, check out the peer-reviewed article titled "Characterization of the Microbiome of Corals with Stony Coral Tissue Loss Disease along Florida’s Coral Reef."

• Restored staghorn corals are more likely to survive if they’re bigger (with branch lengths adding up to 15 centimeters or more) and if they’re planted on specific parts of the reef (known as fore-reef and back-reef habitats) in spots with moderate water flow. The corals are also most likely to survive in certain Florida areas—Biscayne Bay, Broward–Miami, the Dry Tortugas, then the lower Florida Keys. This study, co-authored by Mote scientists in the peer-reviewed journal Restoration Ecology, provides a holistic view with data contributed by multiple partners throughout Florida’s Coral Reef producing novel insight into restoration success.

• Mote scientists developed the first protocol for measuring growth rates of live coral microfragments using structured-light 3D scanning, described in the peer-reviewed journal Frontiers in Marine Science. They found that, by following their protocol, scientists can measure the surface area of corals more accurately and precisely than with current 2D tools, especially corals with complex shapes and rough surfaces. When multiple people conduct scans for multiple projects, 3D scans yield more consistent data than 2D scans. While 3D scanning is not yet as time- or cost-efficient as 2D, Mote’s protocol describes how best to capitalize on its strengths to improve coral research now. 

As these peer-revieweed journal articles shared Mote's results with the world, Mote scientists were busy with multiple new and ongoing studies:

• Mote scientists completed 20 unique staghorn coral breeding events this summer in our land-based system. As part of those efforts, we successfully bred staghorn coral genotypes that can resist the devastating white-band disease, to investigate whether these coral parents can pass disease resistance to their babies.
   
• Mote welcomed its first batch of baby elkhorn corals from parent corals grown in our underwater breeding nursery established in 2020. While these brand new coral parents produced a relatively small number of babies—about 150—this project in Mote’s first land-based spawning system at IC2R3 allowed us to breed our nursery corals with wild fragments we brought in, to enhance the genetic diversity needed for the survival of this severely imperiled coral species. (Learn more about the challenges facing elkhorn coral and how we’re helping in the “Preservation” section below.)
   
• Mote scientists are studying how to give baby corals the best chances to survive by optimizing larval settlement, acquisition of their beneficial algae and post-settlement rearing as they develop into adult coral colonies. This research uses different coral species to investigate the various aspects of settlement and post-settlement rearing to be able to effectively upscale assisted coral sexual reproduction efforts. One study involving the mountainous star coral species is testing the best methods for conditioning substrates (ceramic mounts) on which the coral larvae settle. Coral larvae rely on chemical and spectral (light) cues given off by crustose coralline algae (CCA) to show them where to settle. CCA naturally occurs on reefs and in Mote’s land-based system. By manipulating where and how the CCA grows on the substrates, scientists hope to be able to have greater control over where the larvae will settle, which will help them better care for and grow the baby corals. In another study, Mote scientists are testing the spectral cues associated with CCA and whether larvae prefer to settle on substrates that are similarly colored (e.g., pink, red, purple) or not. Consistent with their predictions, the scientists found that staghorn coral larvae preferred pink and purple substrates the most, while green, blue and orange were the least popular. These results may help to improve settlement rates moving forward as settlement substrates used are typically white or cream colored. A second component of the study is comparing the rate at which the coral babies take up their symbiotic algae when in the presence of adult corals or not. The algae promote growth and survival and can be taken up in different ways. Since the coral babies are very small and vulnerable after they settle, any strategy to accelerate the acquisition of these crucial symbiotic partners should support greater chances of survival. 

• Mote scientists tested 13 treatments for a deadly coral disease called black band disease (BBD), finding highly promising results from one treatment—a natural, topical, antimicrobial and antiviral substance from the company Ocean Alchemists LLC. The detailed results of this project will be shared in the coming year. Mote scientists led the research in the U.S. Virgin Islands in collaboration with the U.S. National Park Service, and results are expected to ripple far and wide, as BBD can sicken or kill corals around the globe.

  In a newer study in progress now, Mote and Ocean Alchemists are testing new potential treatments for the deadly stony coral tissue loss disease (SCTLD) that are antimicrobial and antiviral substances similar to the treatment found for BBD. Other scientists have found that the antibiotic amoxicillin can be used against SCTLD, but alternative treatments must be developed to reduce the risk of antibiotic resistance in coral disease bacteria. The new treatments Mote is testing don’t include antibiotics.

• Mote scientists conducted one of the first studies of how sunscreen affects spawning corals and their offspring. The researchers exposed mustard hill coral (Porites astreoides) to sunscreen continuously for a month and a half, including during their spawning event. The tested sunscreen contained oxybenzone and multiple UV-filter compounds whose potential impacts on corals must be better understood to inform coral conservation and management. Results are being analyzed now.

• 20 groups of scientists from across the nation did research in Mote’s Climate and Acidification Ocean Simulator (CAOS) system this year. Project scientists hailed from Mote, Smithsonian Institution, Oregon State University, University of Southern California, Appalachian State University, College of Charleston, Goshen College, Florida Atlantic University, Old Dominion University, Pennsylvania State University, Louisiana State University, University of Mississippi, and University of Florida. Several peer-reviewed scientific publications came out this year from previous experiments in CAOS, demonstrating the versatility and importance of this system that can house fish, sponges, urchins, macroalgae, and corals under unique temperature and pH levels for short- or long-term studies.

• Strengthening our climate change data: Mote scientists were selected for a competitive grant from SECOORA/IOOS to place a continuous pH monitoring station at Looe Key, Florida, to fill an important monitoring gap in ocean sensing networks for detecting ocean acidification impacts. Ocean acidification, a climate-change impact caused by excess carbon dioxide in the atmosphere entering the ocean, and coastal acidification due to multiple processes, are accelerating challenges affecting multiple marine species in ways that scientists are striving to predict and detect.

• 208 observations from 14 trained observers were submitted to Mote’s BleachWatch program, helping to reveal that corals in the Florida Keys Marine Sanctuary had a relatively mild year of coral bleaching—when corals lose their beneficial algae because of high temperatures or other stressors. 127 of the 208 reports submitted June-October 2021 showed no paling or bleaching, and those that did show paling or bleaching usually reported it for a minority of the corals—except for reports of a few inshore sites where more than half the corals were affected.

• Mote scientists visited 93 underwater sites and surveyed the 41 of those that had coral  this year as members of the Disturbance Response Monitoring (DRM) team within the Florida Reef Resilience Program—a partnership of government, academic and nonprofit organizations. Data from these efforts provide​​ reef managers with an annual assessment of the extent of coral bleaching and disease and its potential impacts on Florida’s Coral Reef. The DRM program is the largest collaborative, volunteer-based coral monitoring effort in the world. Mote, which surveys DRM sites for the Lower Florida Keys and Key West, is often the organization with the largest number of survey sites per year.

• More than $236,000 in competitive grants were awarded for coral science, restoration, and education efforts thanks to sales of the Protect Our Reefs license plate administered by Mote. These projects by multiple institutions, along with Mote’s internal projects also funded by the Reef Plate, are tackling myriad challenges—seeking better ways to detect coral-damaging snails, searching for sources of probiotic bacteria that could benefit coral health, investigating how lobsters affect other animals important to coral reefs, and much more.

PRESERVATION

• ​Mote’s International Coral Gene Bank received its first living corals on Jan. 16, 2021. So far, most of the corals in the Gene Bank are from Mote’s coral nurseries in the Florida Keys, and some elkhorn corals were the offspring of sexual reproduction efforts with coral parents from Florida, Puerto Rico and Curacao. Seven corals in Mote’s Gene Bank were rescued from Florida’s Coral Reef before they could experience the deadly stony coral tissue loss disease (SCTLD). Seven more were rescued from areas of the reef where the SCTLD had been documented, making them potential survivors of the disease.  Biologists at the Gene Bank hope to spawn these corals in an effort to convey disease resilience to their offspring. 
  
  We’re grateful to our colleagues who have contributed corals to our gene bank — Coral Restoration Foundation, The Reef Institute, Florida Coral Rescue Center, and the Florida Fish and Wildlife Conservation Commission — and those who donated coral larvae (babies) for us to settle — Florida Aquarium, Biscayne National Park, and Nova Southeastern University.
  
  This year, we filled our first coral spawning system at the Gene Bank with rescued corals brought to us by FWC. There, we are maintaining environmental conditions that will help the corals mature and produce gametes (eggs and sperm) needed for sexual reproduction to produce valuable, genetically diverse offspring.
  
  Mote’s unique coral Gene Bank has the capacity to store dozens of genetic varieties from at least 30 coral species in triplicate. It is housed in hurricane-resistant infrastructure and contains four separate life-support systems. If one system fails, corals supported by other systems will be preserved.  To avoid confusion with so many species and replicates, corals at the gene bank are in the process of being tagged with RFID chips (pet microchips).  Using this technology, corals can be identified even if their handwritten labels become compromised.  The Gene Bank is a true Noah’s Ark for precious coral genetic diversity needed for reef restoration.

• 41 samples of elkhorn coral (Acropora palmata) were collected, including 18 by Mote scientists, as part of a federally led effort to preserve and then restore this imperiled species that has declined severely on Florida’s Coral Reef. The Florida Palmata Coordination team is led by the National Oceanic and Atmospheric Administration (NOAA) with partnering scientists from Mote and 18 other institutions. Researchers estimate that only about 200 living elkhorn corals remain on Florida’s coral reef, following a dramatic decline over the past 40 years, and in just the past decade, we’ve lost more than half the known genotypes (genetic varieties) on the reef. Project scientists are analyzing corals collected this year to determine how many unique genotypes they represent.

• 25 genotypes of elkhorn coral reside in Mote’s underwater nurseries and 150 genotypes reside in Mote’s landbased nursery—critical raw material for restoration, likely representing most of the elkhorn genetic variation left in the Lower Florida Keys. We boosted the number of genotypes recently by raising new coral offspring from wild elkhorn coral eggs and sperm that we collected and combined in 2020.

• From 2019 to December 2021, 193 samples of staghorn coral (Acropora cervicornis), 314 samples of elkhorn coral (Acropora palmata), and samples from multiple species of mounding corals (197 from Orbicella, 14 from Pseudodiploria and 20 from Montastrea cavernosa) were processed with DNA analysis tools to determine the genetic identity (or genotype) of individual corals, test for clonality, answer population-based questions, and more.

RESTORATION

With more than 32,000 corals restored by Mote scientists this year—our best year ever—we have restored a cumulative total of more than 140,000 corals to Florida’s Coral Reef since 2008.

• The first corals were planted this year by Mote and partners for Mission: Iconic Reefs (M:IR), a NOAA-led, unprecedented collaborative effort to focus highly-aggressive restoration efforts at seven key reefs along Florida’s Coral Reef, all within the Florida Keys National Marine Sanctuary (FKNMS). M:IR builds upon decades of restoration science, including Mote’s, to ensure that the reef will last for generations to come. This year’s efforts focused on the Iconic Reef known as Eastern Dry Rocks, which contains ecologically significant bank habitats. EDR is also economically significant, as one of the closest reefs to Key West.
  
  EDR’s restoration is supported by a $5-million grant awarded In November 2020 to the National Marine Sanctuary Foundation in partnership with Mote Marine Laboratory & Aquarium and Coral Restoration Foundation™ by the National Fish and Wildlife Foundation (NFWF) and NOAA through the National Coastal Resilience Fund. This year, project partners restored 4,284 elkhorn and 2,250 staghorn coral fragments to EDR, and in the next three years, those numbers will grow to 24,000 elkhorn and nearly 10,000 staghorn colonies. 

  Starting at EDR and one other site, Mote scientists are using innovative photogrammetry software to turn 2D images collected by our divers into valuable 3D renderings of reef restoration sites. So far, Mote has imaged approximately 6,500 square meters of reef in an ongoing effort to characterize the habitat at a broad scale before and after coral restoration. We hope our surveys after restoration show increases in coral cover, with more structural complexity that will support more diverse wildlife, and decreases in nuisance species like certain algae. These 3D renderings are being analyzed using novel software provided by Scripps Institute of Oceanography and the Institute of Information Science and Technologies of the Italian National Research Council—among the latest and greatest tools for creating historical records of reefs that we can reference decades into the future.

• Since Mote’s reef restoration launched in 2008, we have planted corals on more than 35 separate reefs spanning nearly 45 miles of Florida’s Coral Reef, not only targeting EDR and other high-profile sites, but also helping to fill gaps to support a more connected, contiguous, ecologically healthy population.

• The first and only coral restoration nursery in Islamorada was brought to life this year by Mote, through a partnership with the famed Bud N’ Mary’s Marina. Just after the fiscal year concluded, Mote introduced the first coral fragments to this new home in the Upper Florida Keys—an exciting expansion of our restoration efforts from their home base in the Lower Keys, including the land-based coral nursery at Mote’s IC2R3 and underwater nurseries at Looe Key and Sand Key.

  2,582 elkhorn coral fragments, including 140 genotypes, are currently under Mote’s care in 10 raceways at the Islamorada Coral Nursery. 10 more raceways are available for future arrivals.

  Even before we populated the Islamorada nursery, Mote and partners were already making a difference in Islamorada. Mote provided 2,575 corals to be restored by citizen-science volunteers with I.CARE (Islamorada Conservation and Restoration Education) this year. A total of 579 I.CARE divers planted: 2,240 of Mote’s staghorn corals across Alligator, Captain Aronos, Rocky Top and Victory reefs; 135 of Mote’s elkhorn corals at Alligator Reef; and 200 massive starlet corals at Rocky Top Reef.