Synthetic Coral Reefs
By Kasia Schab, Sam Poffinbarger and Julia McMahon-Cole
Keywords: North Queensland's Great Barrier Reef, Ocean Acidification, Marine Drones, Crown-of-Thorns-Starfish, Artificial Intelligence
Summary
The Great Barrier Reef (GBR) system is arguably the world’s oldest and most well-known reef, spanning about 2000 kilometers off of the Australian coast. The Crown-of-Thorns Starfish, in the past few decades, have become the GBR’s top threat as the climate continues to harm its health.
With the Great Barrier Reef’s rich biodiversity, as the world’s oldest reef system, and overall ecological significance, the threats it faces due to climate change are not only numerous, but daunting. Coral bleaching is one of the well-known potential stressors to these kinds of reef systems, which occurs when there are increased heat events. The overabundance of Crown-of Thorns Starfish (COTS) species, native to the area, exacerbates and speeds up coral loss, only compounding on the bleaching effects. In the past years, governments have given more attention and investments in conservation research, as well as action, to tackle this specific issue. This support has led to technologies like Ranger bots, a robot that is programmed to target COTS by injecting a natural bile directly into them, as well as Larval bots, which deals with repopulating old coral with nursery coral polyps. These kinds of innovative technologies highlight real promise for future reef systems, marine restoration and potential for management. |
Ecological Genealogy
Australia's Great Barrier Reef system is an exceptional case study for exploring the ramifications of ocean acidification, owing to its vast expanse both geologically and on the global stage, alongside its pivotal role in ecotourism. Situated off the northeast coast of Australia, the incredible GBR system stands as arguably the largest coral reef system ever known, with its formation tracing back over 300,000 years (Davies, 2011). Today, this extraordinary ecosystem harbors an astonishing array of marine life, boasting over 1,625 fish species, 600 coral types, and countless other organisms (Healey, 2018). It's integral to recognize that the Great Barrier Reef is not a static entity but a living, evolving ecosystem, continuously responding to environmental shifts and interactions.
The origins of this reef system extends millennia into the past. While the foundations of the Great Barrier Reef is believed to have formed over 300,000 years ago, according to data collected from sedimentological drilling (Davies, 2011), the modern GBR as we know it today began its formation during the conclusion of the Pleistocene epoch, approximately 11,700 years ago. Geological shifts and changes, like warmer waters, sea-level ebbs and flows, as well as plate collision, allowed for more coral organisms to settle on the ocean floor, begin to grow, and colonize the shells and different invertebrate skeletons of the area during the beginning of the GBR’s formation (Davies, 2011). Following the most recent ice age (end of the Pleistocene), the lowered sea levels allowed for fertile grounds for the growth of what we now know as the GBR, around 6,000 to 9,000 years ago (Healey, 2018). A specific species that has played an unprecedented role in the GBR ecosystem is the Pacific crown-of-thorns starfish (COTS), or Acanthaster. cf. solaris. COTS has historically been a native predator species within the complex GBR system, and primarily is responsible for eating hard coral, which when in correct balance, is a vital role (AIMS, 2023). However, due to increasing human activity, leading to coral vulnerability and weakness, overpopulation outbreaks of COTS have been at a historic high over the past forty years (Wooldridge & Brodie, 2015). But the geological history of the Great Barrier Reef system is not the only existing knowledge we have about this complicated and diverse ecosystem; some of the indigenous peoples of Australia, have had a long and interactive history with this majestic marine system as well. There are over forty Traditional Owner groups that claim interest in the area where the GBR system exists today, pushing for Indigenous land/marine stewardship, management and education (Dale et al., 2016). To many of the different nations of Aboriginal and Torres Strait Islanders, the GBR system has a huge cultural significance, and can be seen in its prominence within their paintings, songs and stories that have been passed down through generations, documented connections going back 60,000 years (Kwek, 2014). |
Johnson, Johanna. (2014).
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Present tense
As we have established, the Great Barrier Reef is one of the world's most biodiverse and complex ecosystems that supports a diverse array of marine life (Healey, 2018). The GBR system, spanning around 2000 km, is situated on a shallow continental shelf with high nutrient and sediment discharge from nearby agricultural areas, making it susceptible to poor water quality due to improper nutrient concentrations. Thirty-five major rivers, including the Burdekin, Fitzroy, and Daintree discharge 5-8 times more nutrients and sediment than in pre-colonial times, leading to increased phytoplankton, coastal acidification, and reduced biodiversity (Smith, 2020). The GBR system faces threats, such as climate change, poor water quality, coastal development, and illegal fishing, resulting in the loss of almost half of its coral cover since 1985 (Healey, 2018). Coral bleaching events, exacerbated by heat stress and many of the above factors all pose significant challenges for the reef system. The GBR experienced a devastating bleaching event in 2016, causing approximately 22% of coral to die in the northern section (Healey, 2018). These abiotic factors leading to coral reef bleaching and decline also have the knock on effect of allowing biotic drivers like Crown-of-Thorns Starfish to have an increasing negative impact on the reef systems in the GBR.
Crown-of-Thorns Starfish (COTS) pose a significant threat to the Great Barrier Reef (GBR) ecosystem, contributing to coral loss in the Indo-Pacific region (Westcott, 2020). Despite manual control programs dating back to the 1960s, their effectiveness has been limited. The GBR, a world heritage area, has experienced degradation primarily due to factors like COTS outbreaks and climate change-induced coral bleaching. Since 2008, there has been a resurgence of COTS outbreaks in the GBR, causing coral loss mainly in areas unaffected by recent mass bleaching events (Westcott, 2020). Strategic and repeated manual control has proven effective in rapidly reducing COTS densities and shifting the population size structure towards less damaging individuals, ultimately leading to the recovery of hard coral cover (Westcott, 2020). While efforts to improve water quality are crucial for the reef's resilience, they have not yet resulted in detectable changes. One approach to tackle this issue is by undergoing classical ecological restoration, which looks at the recovery of ecosystems that have been damaged, degraded, or destroyed (Higgs et. al., 2014). This form of restoration also focuses on the historical function of an ecosystem, how it was, and how it looked prior to human disturbance. In the case of the Great Barrier Reef the history of this ecosystem's function is valuable information, as it will provide an idea as to how the ecosystem might operate under new conditions and shifting baselines. Overall, manual control using traditional restoration remains the most effective means of addressing the threat posed by COTS and supporting reef resilience in the face of global environmental change, but new technologies may soon outpace the traditional restoration methods. Efforts to address these challenges include significant investments by the Australian and Queensland governments, totalling 200 million Australian dollars annually (Healey, 2018, p.29). Initiatives like the Reef 2050 long-term sustainability plan, Reef Trust, the Great Barrier Reef Gully, and Streambank Joint Program aim to improve water quality, reduce sedimentation, and enhance overall reef health. The Reef 2050 long-term sustainability plan is a multi-stage management plan to alleviate and improve the negative factors affecting the GBR. The current stage outlines how government, industry and communities will work to improve water quality going into the ocean by improving agricultural and industrial runoff that runs into the major rivers (Healey, 2018). Additionally, the Queensland and Australian governments have begun to employ new A.I. technologies, like the innovative RangerBot to combat the COTS uprising. |
Future Trajectory
Over the most recent decades, as the climate has been warming, the GBR has slowly been dying and facing degradation due to oceans getting warmer, water pH levels decreasing and more human activity. With the way our climate is warming at such high speeds the future for coral reefs is not a positive one. If oceanic temperatures keep rising, coral reefs in the GBR will become extinct by the end of the century, unless there are dramatic action-based changes that could be done to help support the coral reef systems. Ocean acidification poses a monumental problem to many marine ecosystems. As the atmosphere gets hotter the oceans also become warmer and many marine plants and animals suffer the consequences. If we don't reduce our reliance on fossil fuels, ocean life will cease to exist.
A recent study to help restore the GBR has been done using underwater drones (Rangerbots) to inject the Crown-of-thorns starfish, or COTS, with lethal toxins which causes the starfish to instantly be eliminated. Technology like these Rangerbots will become more advanced and will eventually be able to cover a larger scale of the GBR. A sister project that includes the deployment of tiny baby coral by the use of drones called LarvalBot is the next step into ensuring the survival of the GBR. These Larvalbots will eventually become ‘mothers’ to hundreds of baby coral. They will be able to release these baby coral into the dying areas of the GBR in a technique called larval restoration. This project will allow for reefs to grow and restore into healthy thriving coral. Another example of exciting future research is heat/pH level detection-mapping drones, these can be built in order to locate where there are lower concentrations of pH levels and high levels of heat. Once detected these drones can provide cooling effects that will decrease the rising temperature of the ocean in specific areas caused by ocean acidification which will result in overall survival of the GBR. Such technology will be beneficial as it will allow for oceanic life, specifically coral reefs to recover and invasive species such as COTS to be kept at appropriate rates. By studying the GBR history and understanding how it functioned before humans, it can illuminate a strategy for people to plan a future in which the GBR has a greater chance of surviving. If the history of the Great Barrier Reefs can be studied in more depth it will be easier to figure out a holistic restoration plan, one that will not only help the coral recover from ocean acidification, but will also help coral in the face of more changes due to climate change. Technology has the ability, if used correctly, to become a huge benefit for our coral reefs that are facing extinction. |
(Westcott 2022, 3.)
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References
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Dale, A., George, M., Hill, R., & Fraser, D. (2016). Traditional Owners and Sea Country in the Southern Great Barrier Reef–Which Way Forward?.
Davies, P. J. (2011). Great Barrier reef: origin, evolution, and modern development. Encyclopedia of modern coral reefs: structure, form and process: Springer, Dordrecht, 504-534.
Higgs, E., Falk, D. A., Guerrini, A., Hall, M., Harris, J., Hobbs, R. J., Jackson, S. T., Rhemtulla, J. M., & Throop, W. (2014). The changing role of history in restoration ecology. Frontiers in Ecology and the Environment, 12(9), 499–506. https://doi.org/10.1890/110267
Healey, J. (Ed.). (2018). Saving the Great Barrier Reef. Spinney Press. https://ebookcentral-proquest-com.ezproxy.library.uvic.ca/lib/uvic/detail.action?pq-origsite=primo&docID=5452496
Johnson, Johanna. (2014). Status of marine and coastal assets in the Wet Tropics region of the Great Barrier Reef. 10.13140/RG.2.1.2073.5523.
Knowlton, N. (2012, October). The Great Barrier Reef – Going, Going, Gone??? | Smithsonian Ocean. Ocean.si.edu. https://ocean.si.edu/ecosystems/coral-reefs/great-barrier-reef-going-going-gone
Kwek, G. (n.d.). Great Barrier Reef survival key to indigenous identity . Science X Network. https://phys.org/news/2014-10-great-barrier-reef-survival-key.html
Lam, V. W., Chavanich, S., Djoundourian, S., Dupont, S., Gaill, F., Holzer, G., ... & Hall-Spencer, J. M. (2019). Dealing with the effects of ocean acidification on coral reefs in the Indian Ocean and Asia. Regional Studies in Marine Science, 28, 100560.
Mankad, A., Hobman, E. V., & Carter, L. (2021). Genetically Engineering Coral for Conservation: Psychological Correlates of Public Acceptability. Frontiers in Marine Science, 8. https://doi.org/10.3389/fmars.2021.710641
Smith, J. N., Mongin, M., Thompson, A., Jonker, M., De’ath, G., & Fabricius, K. (2020). Shifts in coralline algae, macroalgae, and coral juveniles in the Great Barrier Reef associated with present‐day ocean acidification. Global Change Biology, 26(4), 2149–2160. https://doi.org/10.1111/gcb.14985
Technology (QUT), Q. U. of. (n.d.). Restore the Great Barrier Reef. QUT. https://www.qut.edu.au/engage/giving/support-research/great-barrier-reef
Westcott, D.A., Fletcher, C.S., Kroon, F.J. et al. (2020). Relative efficacy of three approaches to mitigate Crown-of-Thorns Starfish outbreaks on Australia’s Great Barrier Reef. Sci Rep 10, 12594, 1-12. https://doi.org/10.1038/s41598-020-69466-1
Wolanski, E. (1994). Physical Oceanographic Processes of the Great Barrier Reef (1st ed.). CRC Press. https://doi-org.ezproxy.library.uvic.ca/10.1201/9781351075602
Wooldridge, S. A., & Brodie, J. E. (2015). Environmental triggers for primary outbreaks of crown-of-thorns starfish on the Great Barrier Reef, Australia. Marine pollution bulletin, 101(2), 805-815.
Dale, A., George, M., Hill, R., & Fraser, D. (2016). Traditional Owners and Sea Country in the Southern Great Barrier Reef–Which Way Forward?.
Davies, P. J. (2011). Great Barrier reef: origin, evolution, and modern development. Encyclopedia of modern coral reefs: structure, form and process: Springer, Dordrecht, 504-534.
Higgs, E., Falk, D. A., Guerrini, A., Hall, M., Harris, J., Hobbs, R. J., Jackson, S. T., Rhemtulla, J. M., & Throop, W. (2014). The changing role of history in restoration ecology. Frontiers in Ecology and the Environment, 12(9), 499–506. https://doi.org/10.1890/110267
Healey, J. (Ed.). (2018). Saving the Great Barrier Reef. Spinney Press. https://ebookcentral-proquest-com.ezproxy.library.uvic.ca/lib/uvic/detail.action?pq-origsite=primo&docID=5452496
Johnson, Johanna. (2014). Status of marine and coastal assets in the Wet Tropics region of the Great Barrier Reef. 10.13140/RG.2.1.2073.5523.
Knowlton, N. (2012, October). The Great Barrier Reef – Going, Going, Gone??? | Smithsonian Ocean. Ocean.si.edu. https://ocean.si.edu/ecosystems/coral-reefs/great-barrier-reef-going-going-gone
Kwek, G. (n.d.). Great Barrier Reef survival key to indigenous identity . Science X Network. https://phys.org/news/2014-10-great-barrier-reef-survival-key.html
Lam, V. W., Chavanich, S., Djoundourian, S., Dupont, S., Gaill, F., Holzer, G., ... & Hall-Spencer, J. M. (2019). Dealing with the effects of ocean acidification on coral reefs in the Indian Ocean and Asia. Regional Studies in Marine Science, 28, 100560.
Mankad, A., Hobman, E. V., & Carter, L. (2021). Genetically Engineering Coral for Conservation: Psychological Correlates of Public Acceptability. Frontiers in Marine Science, 8. https://doi.org/10.3389/fmars.2021.710641
Smith, J. N., Mongin, M., Thompson, A., Jonker, M., De’ath, G., & Fabricius, K. (2020). Shifts in coralline algae, macroalgae, and coral juveniles in the Great Barrier Reef associated with present‐day ocean acidification. Global Change Biology, 26(4), 2149–2160. https://doi.org/10.1111/gcb.14985
Technology (QUT), Q. U. of. (n.d.). Restore the Great Barrier Reef. QUT. https://www.qut.edu.au/engage/giving/support-research/great-barrier-reef
Westcott, D.A., Fletcher, C.S., Kroon, F.J. et al. (2020). Relative efficacy of three approaches to mitigate Crown-of-Thorns Starfish outbreaks on Australia’s Great Barrier Reef. Sci Rep 10, 12594, 1-12. https://doi.org/10.1038/s41598-020-69466-1
Wolanski, E. (1994). Physical Oceanographic Processes of the Great Barrier Reef (1st ed.). CRC Press. https://doi-org.ezproxy.library.uvic.ca/10.1201/9781351075602
Wooldridge, S. A., & Brodie, J. E. (2015). Environmental triggers for primary outbreaks of crown-of-thorns starfish on the Great Barrier Reef, Australia. Marine pollution bulletin, 101(2), 805-815.