MODERN PIONEERING IN CORAL REEF RESTORATION: MICROFRAGMENTATION Emily Ng

MODERN PIONEERING IN CORAL REEF RESTORATION: MICROFRAGMENTATION

Writt en By Emily Ng Designed By Lynne Kim

CIntroduction oral reefs are vital components of nature’s aquatic ecosystems. Over 1 million aquatic species depend on coral reefs to serve as feeding, habitation, and nursing grounds. Furthermore, approximately 25% of ecosystems depend on the existence of these reefs for habitation. Coral reefs also serve as a form of natural coastal protection, preserving life against destructive phenomena like tsunamis and storms. However, climate change has led to the endangerment of coral reefs in recent decades. At the time of its enactment in 2014, the Endangered Species Act stated that 22 coral species were considered as threatened, and 2 are endangered. Since then, the number of endangered coral species have increased rapidly, which also places the lives of various aquatic organisms in jeopardy. A specifi c consequence of climate change includes mass bleaching, which remains as one of the prime drivers of coral reef deterioration. The rise in intensity of mass coral bleaching is due to the increase in global temperatures. Bleaching mortality is rapidly escalating in various regions in the world—even the Great Barrier Reef, the largest coral reef in the world, is facing increased levels of bleaching. Public interest has been gradually pushing for international efforts to preserve and recover coral reefs. Microfragmentation, an extensive process in which coral is regenerated from its smaller counterparts, is a prominent example of modern solutions. Several groups have been advocating for more attention on this subject, such as Mote Marine Laboratory in Florida, an independent nonprofi t that is currently undertaking microfragmentation as a recent initiative. Such efforts, however, have also been countered by the need for more funding and governmental cooperation within global intervention.

Mass Bleaching

Derived from climate change, mass bleaching is a key driver of coral reef deterioration. The survival of coral depends on their symbiotic relationship with algae. Algae produces sugars using sunlight, and most are passed into the coral. In exchange, coral gives carbon and nitrogen to algae from their waste. Coral has the tendency to bleach when heat stress disrupts their symbiotic relationship with algae.

One proposal suggests that bleaching may be due to damage toward algae’s photosynthetic processes from high temperatures. Struggles to process light properly produce reactive oxygen and nitrogen species (e.g., hydrogen peroxide) as a harmful byproduct. Such Spring 2022 | PENNSCIENCE JOURNAL

molecules can damage proteins, so the coral host cell rejects these defective algae, which halts their symbiotic relationship and leads to bleaching. Furthermore, a 2018 study on parasitism in a coral reef ecosystem suggests that algae may become hostile in elevated water temperatures. Kim Ritchie, microbiologist in the Mote Marine Laboratory in Sarasota, recently discovered that higher temperatures can eliminate probiotic bacteria in coral reefs. These antibioticproducing bacteria fi ght off other pathogenic strains. This has led to an extensive and expanding search for fi nding bacteria that would grant coral immunity against such pathogens.

In recent years, studies have determined that some coral reefs may possess thermal adaptations in response to prolonged high temperatures. Nevertheless, regions such as Micronesia and western Polynesia are still extremely vulnerable to climate change, and only rapid, monumental efforts in suppressing climate change would eliminate mass bleaching in these regions.

Microfragmentation

Former restoration efforts have revolved around the usage of large fragments of coral. In this process, these fragments grow larger in size using in situ coral nurseries located at the original location of the corals. Once fully grown, they are often planted onto degraded reefs, and their development and survival are recorded. However, the need for larger pieces in this process requires the rapid growth of large coral reef species. Most massive corals usually possess relatively slow growth rates, which are unable to keep up with the immediate need for recovery. Microfragmentation introduces smaller pieces of fragments that have the potential to improve the rate of coral reef growth. Prior to outplanting, such pieces are cut to around 1 cm2 or less and grown to about 6 cm2. This is extremely small in comparison to larger pieces that have been used in stimulating regrowth of coral reefs (16-64 cm2). Even so, early success in research trials have presumed microfragmentation to be more high-yielding. A 2013 study by Mote Marine Laboratory on the outplanting of Orbicella faveolata and Montastrea cavernosa fragments on reefs in the Florida Keys demonstrated major fi ndings. Similar survival rates were found between 6 microfragments and 1 larger fragment, and all of these fragments were derived from the same material. Positive results like these continue to drive efforts to refi ne microfragmentation.

Rather than just serving as a means of effective and effi cient recovery, microfragmentation can also be used as an experimental tool. Microfragmentation could determine areas in which growth of certain corals are the most fi t as well as causes of death. The method can also be used to identify which coral species are especially vulnerable to bleaching as well as which are resistant.

Notably however, microfragments are subject to predators, such as parrotfi sh, at a higher rate than larger fragments of coral. In reference to Mote’s 2013 study, it suggests that the microfragments of the coral reef species O. faveolata can produce around 10 times more tissue than its larger counterparts. This deduction, however, only took into account arrays of microfragmentation exhibiting less than 40%

predation relative to other arrays. Thus, predation is a necessary factor to consider when refi ning the process of microfragmentation.

The need to protect microfragments throughout their stages of growth suggests that rapid recovery of coral reefs is only possible with increased investment. Thus, funding is crucial in implementing microfragmentation on a global scale. Furthermore, it is still unclear if successful reproduction of coral is dependent on size, not just age.

The Need For Funding

Facilitating microfragmentation on a global scale requires various equipment and cooperation. For instance, Frank Mars’s

Coral Reef Rehabilitation

Project has installed over 8,600 hexagonal steel structures (“spiders”) to plant microfragments onto the ocean oor nearby existing coral reefs. However, the potential of these positive advancements are limited without su cient funding. In the case of this particular rehabilitation project, much of the funding comes directly from philanthropists, not from federal agencies. No two coral reefs are the same, rendering experimentation in regrowth a primary concern. Mandated funding for coral research is crucial to providing such necessary exibility.

Furthermore, funding for coral reef restoration is o en limited in duration and in quantity. e short cycles of a majority of restoration projects inhibits precision and accuracy across all data collected from various sources. Such funding also motivates many researchers to limit the sample size of their experiments, which hinders the ability to create e ective conclusions regarding the success of microfragmentation.

e sources of increasing necessary funding remain unknown. At the moment, there is still not enough global concern to push for support behind microfragmentation and on coral reef recovery e orts on the whole. Some experts believe that such e orts would be relatively cheap, but it is up to others to be willing to take this leap that will lead to change. Dave Vaughan, who is spearheading e orts in microfragmentation at Mote Marine Laboratory, predicted that only $1-2 million is needed to save elk horn coral populations in Florida. Similar e orts across coral reef restoration are also cheaper than anticipated, and their enactment ultimately comes down to the willingness from international powers to collaborate with scienti c intervention. As research continues to search for more sustainable methodology, the need for recovery becomes more and more pressing.

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