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Executive Summary

In the past three decades, bleaching events—a stress response that results from extended warm periods—have caused reef-wide declines in coral across the Great Barrier Reef. Managing climate change is crucial to ensure the long-term survival of the Great Barrier Reef, and if the Great Barrier Reef is to be properly managed into the future, further research on seawater chemistry should be conducted in order to better understand the correlation between climate change and effects on coral growth. Coral reefs are one of the most diverse marine ecosystems on earth. Reef-building coral are able to support a wide range of ecosystem services due to their ability to build calcium carbonate reef systems. Various environmental variables such as, climate change, warming ocean temperatures, increased levels of carbon dioxide, and ocean acidification all influence the progression of coral calcification. Decreased levels of anthropogenic carbon dioxide emissions will allow calcification rates to become steady and maintainable. Considering that colonies respond differently to varied levels of carbon dioxide emissions, it is important that these environmental parameters are evaluated, and tests are done on multiple coral species to get a better understanding of future coral reef stability.

 

https://www.wwf.org.au/what-we-do/oceans/great-barrier-reef

https://www.barrierreef.org/

Draft of Paper

In the past three decades, bleaching events, a stress response that results from extended warm periods, have caused tremendous declines in coral across the Great Barrier Reef. Not only do increasing temperatures impact ocean acidification but it also controls seawater pH, both of which are important drivers of coral calcification. Coral calcification plays an important role in determining the health of reef ecosystems, as numerous species associated with reefs depend on the foundations provided by coral skeletons. Evidence of species tested to date indicate that calcification rates of tropical reef building corals will be reduced by 20-60%. A numerical modeling approach was taken to solve the interactions between the drivers of calcification. This approach analyzed the effects of environmental parameters on coral calcification. A majority of the marine calcifiers tested were sensitive to changes in the carbonate saturation state and have shown a decline in calcification rates. Results show that the impacts of climate change/heat stress on the global oceans have reached unprecedented extremes and changes in the chemistry of the seawater have caused coral to grow improperly. When seawater absorbs carbon dioxide, chemical reactions occur that reduce seawater pH, thus leading to ocean acidification. Increased levels of carbon dioxide reduces the ability of corals, that are still reef-building, to produce their hard skeletons. The results from this study suggest that climate change is the most severe threat to the Great Barrier Reef and is projected to lead to coral bleaching and changes to the abundance of marine species. Managing climate change is crucial to ensure the long-term survival of the Great Barrier Reef, and if the Great Barrier Reef is to be properly managed into the future, further research on seawater chemistry should be conducted in order to better understand the correlation between climate change and effects on coral growth.

This map shows coral reef distribution is in Queensland, Australia. The black lines show the depth contours. The orange dashed lines show transient currents. The red lines show surface currents. The scattered colorful dots show individual reefs separated into different geographical zones1 Map from Mongin, M., et al. (2016).

Above is a picture retrieved the National Center for Ecological Analysis and Synthesis (National Center for Ecological Analysis and Synthesis) depicting a lively and healthy coral reef. Healthy coral reefs contain thousands of fish and other species that can be found nowhere else on earth. Below is a picture retrieved from the Ocean Agency (The Ocean Agency). depicting a lifeless, acidified reef in Queensland, Australia. Weather-related damage to reefs lead to the decline in marine life biodiversity. The continuation of stress on coral could result in their disappearance in the ocean.

Above is a picture retrieved from the Ocean Agency  (The Ocean Agency) showing the same coral reef over the span of three major bleaching events due to warming ocean temperatures. Below is a graph showing the relationship between heat exposure and the amount of bleaching measured underwater in March and April of 2017. Graph from Hughes,T., et al. (2017).

The table above is showing estimated trends in years and sea-surface temperature (Cooper, T., et al., 2008). These estimates for skeletal density, annual extension and calcification were all based on different coral colony profiles as part of a mixed model analysis. Results show that over the years skeletal density, annual extension, and calcification have declined. As a result to climate change, thermal stress and warming oceans are few of the many environmental factors that have influenced the decline in calcification. Table modified from Cooper, T., et al (2008).

About 30% of the carbon dioxide emitted into the Atmosphere every year is absorbed by the world’s surface oceans. Thus, ultimately leading to a shift in the seawater carbonate chemistry (Albright, R., et al., 2013). Concentrations of carbon dioxide increases and the pH of seawater decreases. This relationship is known as ocean acidification (Albright, R., et al., 2013). Since preindustrial times, carbon dioxide uptake by the surface ocean waters have lowered seawater pH, increasing acidity of about 30% (Albright, R., et al., 2013). Much of the carbon dioxide that the ocean absorbs is anthropogenic; meaning that the carbon dioxide absorbed comes from human activity. Coral reefs can experience fluctuations in seawater carbonate chemistry on both daily and seasonal timescales (Albright, R., et al., 2013). These processes can alter based on a wide range of environmental factors, including biological activity, water depth, physical forcing, tide water activity, community composition, and residence time (Albright, R., et al., 2013)..Chemical conditions in seawater vary from reef to reef and will differ from open ocean conditions (Albright, R., et al., 2013).

Coral calcification is an important determinant of the health of reef ecosystems, as tens of thousands of species associated with reefs depend on the structural complexity provided by coral skeletons (De’ath, G., et al., 2009). Calcification increases linearly with increasing sea surface temperature and responds nonlinearly to annual temperature anomalies6. Increasing temperature stress and a declined state of seawater saturation could potentially diminish the ability for the Great Barrier Reefs’ corals to deposit calcium carbonate  (Cooper, T., et al., 2008).

Coral reefs are one of the most diverse marine ecosystems on earth. Reef-building coral are able to support a wide range of ecosystem services due to their ability to build calcium carbonate reef systems (Courtney, T., et al. (2017). Various environmental variables such as, climate change, warming ocean temperatures, increased levels of carbon dioxide, and ocean acidification all influence the progression of coral calcification. Decreased levels of anthropogenic carbon dioxide emissions will allow calcification rates to become steady and maintainable. Considering that colonies respond differently to varied levels of carbon dioxide emissions, it is important that these environmental parameters are evaluated, and tests are done on multiple coral species to get a better understanding of future coral reef stability.

Outline

Introduction

  • Background/Thesis: In the past three decades, bleaching events—a stress response that results from extended warm periods—have caused reef-wide declines in coral across the Great Barrier Reef. Managing climate change is crucial to ensure the long-term survival of the Great Barrier Reef, and if the Great Barrier Reef is to be properly managed into the future, further research on seawater chemistry should be conducted in order to better understand the correlation between climate change and effects on coral growth.

Argument 3

  • Argument: Climate change inhibits coral calcification in the Great Barrier Reef which prevents coral reefs from adequately growing their skeletons.
  • Evidence: Calcification is the process by which corals produce calcium carbonate (CaCO3). Coral calcification rates are proportional to sea surface temperatures. Changes in coral reef calcification associated with ocean warming outweighs those associated with decreases in seawater (Ω) aragonite. Data suggests that regional changes to coral reef calcification will vary depending on local CO2 conditions and ocean warming.
  • Counter: Though individuals (e.g. U.S. 45th) could argue that climate change and/or global warming is a hoax, there is scientific evidence that shows us that the Earth’s temperature has been rising for decades now. It is important that climate change deniers and advocates take into consideration the facts, and not make judgements simply on their own beliefs or opinions.

Argument 2

  • Argument: About 30% of the carbon dioxide emitted into the Atmosphere every year is absorbed by the world’s surface oceans. Thus, ultimately leading to a shift in the seawater carbonate chemistry.
  • Evidence: Concentrations of carbon dioxide increases and the pH of seawater decreases. This relationship is known as ocean acidification. Since preindustrial times, carbon dioxide uptake by the surface ocean waters have lowered seawater pH, increasing acidity of about 30%. Much of the carbon dioxide that the ocean absorbs is anthropogenic; meaning that the carbon dioxide absorbed comes from human activity.
  • Counter: There are multiple individuals who would disagree with this argument due to climate change denial. Carbon dioxide is one of the most prominent gasses in the atmosphere and it should be noted that even though people do not believe this, it is a gas that should not be overlooked.

Argument 1

  • Argument: Weather-related damage to reefs lead to the decline in marine life biodiversity. The continuation of stress on coral could result in their disappearance in the ocean.
  • Explanation: Increasing temperature stress and a declined state of seawater saturation could potentially diminish the ability for the Great Barrier Reefs’ corals to deposit calcium carbonate.
  • Counter: It can be argued that “coral have time,” or that “it’s only temporary” but in reality, once a reef dies so too does the marine life that rely on them. It takes decades for coral to rebuild themselves and in the midst of this phase, the biodiversity could expect to plummet.

Conclusion

  • Coral reefs are one of the most diverse marine ecosystems on earth. Reef-building coral are able to support a wide range of ecosystem services due to their ability to build calcium carbonate reef systems. Various environmental variables such as, climate change, warming ocean temperatures, increased levels of carbon dioxide, and ocean acidification all influence the progression of coral calcification. Decreased levels of anthropogenic carbon dioxide emissions will allow calcification rates to become steady and maintainable. Considering that colonies respond differently to varied levels of carbon dioxide emissions, it is important that these environmental parameters are evaluated, and tests are done on multiple coral species to get a better understanding of future coral reef stability.

Argument

Argument: Weather-related damage to reefs lead to the decline in marine life biodiversity. The continuation of stress on coral could result in their disappearance in the ocean.

Evidence: Increasing temperature stress and a declined state of seawater saturation could potentially diminish the ability for the Great Barrier Reefs’ corals to deposit calcium carbonate.

Counter-Argument: It can be argued that “coral have time,” or that “it’s only temporary” but in reality, once a reef dies so too does the marine life that rely on them. It takes decades for coral to re-build themselves and in the midst of this phase, the biodiversity could expect to plummet.

Laura Fauthauer

It was very interesting to hear about the Copyright Duration and the Mickey Mouse Curve. Every time the copyright was about to expire, Walt Disney would fight to upkeep their credibility with Mickey given that he is their top income attraction. I also thought it was interesting to see images from “Old Columbus” during the floods (e.g. post flood photos). I enjoyed the ways in which we viewed google maps for a generic search and from there, once clicked, it directed you to an old image of what things were like during a specific period in time.

Argument

Argument: About 30% of the carbon dioxide emitted into the Atmosphere every year is absorbed by the world’s surface oceans. Thus, ultimately leading to a shift in the seawater carbonate chemistry.

Evidence: Concentrations of carbon dioxide increases and the pH of seawater decreases. This relationship is known as ocean acidification. Since preindustrial times, carbon dioxide uptake by the surface ocean waters have lowered seawater pH, increasing acidity of about 30%. Much of the carbon dioxide that the ocean absorbs is anthropogenic; meaning that the carbon dioxide absorbed comes from human activity.

Counter-Argument: There are multiple individuals who would disagree with this argument due to climate change denial. Carbon dioxide is one of the most prominent gasses in the atmosphere and it should be noted that even though people do not believe this, it is a gas that should not be overlooked.

TradeMark Gunderson

Copyright is a legal right that is guaranteed to an original piece of work. I enjoyed the part of the short lecture about “Mashup” or “Copy & Paste” because individuals do tend to cut and not realize that it violates copy right laws. It can be very tempting, especially for students, to take the easy way out and simply copy and paste information to get to their end goal faster but in actuality, this only hurts the credibility of your work because it is not original. This is something that all students, and professionals, should be hyper-cognitive of through the course of doing their work.

Scott Cantor

This presentation was very eye opening as Scott discussed many topics that had not been prior knowledge to me. One of the most interesting things that was discussed was 1. The policy controls that governments have over their citizens web browsing and 2. The vast amount of information on the dark web. These are things that can be assumed, but hearing it come directly from an expert was reassuring. The information provided, especially in the context of web searching, has made me more hyper aware of the websites used by me and also the sites in which my information is coming from.

Argument

Argument: Climate change inhibits coral calcification in the Great Barrier Reef which prevents coral reefs from adequately growing their skeletons.

Evidence: Calcification is the process by which corals produce calcium carbonate (CaCO3). Coral calcification rates are proportional to sea surface temperatures. Changes in coral reef calcification associated with ocean warming outweighs those associated with decreases in seawater (Ω) aragonite3. Data suggests that regional changes to coral reef calcification will vary depending on local CO2 conditions and ocean warming.

Counter-Argument: Though individuals (e.g. U.S. 45th) could argue that climate change and/or global warming is a hoax, there is scientific evidence that shows us that the Earth’s temperature has been rising for decades now. It is important that climate change deniers and advocates take into consideration the facts, and not make judgements simply on their own beliefs or opinions.

Annotated Bibliography

Hughes, T., et al. (2017) Global warming and recurrent mass bleaching of corals. Springer nature. Vol 543. DOI:10.1038/nature21707

This article was written only two years ago and therefore, has very up to date information relating current global warming trends. I found this source through the journal database Nature, an accredited site with peer-reviewed scholarly articles. This source was fairly easy to come across as my search came directly from the website itself (i.e. Nature). This article will be used to help aid in explaining some of the effects of global warming on the environment as a whole, and how that in turn has an impact on sea-life (e.g. coral reefs).

 

Mongin, M., et al. (2016) The exposure of the Great Barrier Reef to ocean acidification. Nature. 7:10732 doi: 10.1038/ncomms10732.

This article was written three years ago and the data provided can be closely followed as it reflects modern trends of ocean acidification. This article will help me better explain to the audience how the Great Barrier Reef specifically is exposed in a negative manner. This article comes from a journal publication called Nature. The search engine used for this source was vie Google Scholar.

 

Courtney T., et al. (2017) Environmental controls on modern scleractinian coral and reef-scale calcification. Sci. Adv. 3 (11) e1701356. DOI: 10.1126/sciatic.1701356

This article was written a few years ago and is very relevant to my topic as it discusses the environmental controls on the degradation of these coral reefs. The article can provide me valuable insight on coming to terms with the fact that global warming has a domino effect; there is no one thing that is affected. This article comes directly from The National Center for Biotechnology Information; a website that has direct links to journal pdfs. This journal was searched for via Google scholar and the link given directed me to an external website to download the pdf document.