UNESCO Scientists Explain Why the Great Barrier Reef Is in Danger: New Report

Posted on January 6, 2023January 6, 2023 by Team Writer

great barrier reef in danger — Source: WHC UNESCO/Ko Hon Chiu Vincent

The Great Barrier Reef, located off the Australian coast, is the largest coral reef ecosystem on the planet and one of the most outstanding world heritage sites. It serves as a vast sanctuary for thousands of marine species, protects surrounding islands from storms, provides food, and generates revenue through ecotourism. But the Great Barrier Reef is now in great danger as it experiences its sixth massive coral bleaching event.

A new report from UNESCO scientists explains that the Great Barrier Reef is suffering from accelerating damages from human-caused climate change. They argue that the area must be listed in the record of world heritage sites as “in danger” because the deterioration is accelerating at an alarming phase, pushing the reef’s health beyond its tipping point.

In this article, we’ll review the main points of the new UNESCO report on the Great Barrier Reef and explore the global response to the report.

Background Information: What is Ocean Acidification?

Full Report: Report on the Joint World Heritage Centre/IUCN reactive monitoring mission to the Great Barrier Reef (Australia from 21 to 30 March 2022) (UNESCO, Nov 2022)

Why Is the Great Barrier Reef in Danger?

Since 2015, the Great Barrier Reef has been experiencing massive coral bleaching events due to increasing ocean temperatures and ocean acidification. In fact, in 2021, scientists discovered that the global population of living corals has declined by 50% since the 1950s. This is due in large part to the ongoing usage of fossil fuels such as coal, oil, and gas around the world.

Recent UNESCO scientists’ assessments of the Great Barrier Reef found that it is experiencing its sixth massive coral bleaching event, pushing the reef’s damage to an irreversible tipping point.

During their monitoring, scientists discovered around 750 out of 3,000 reefs within the Great Barrier Reef are suffering from widespread bleaching. That is about 25% of the Great Barrier Reef.
James Cook University marine biology professor Jodie Rummer explains that even the healthiest coral may take a decade to recover from bleaching, and with consecutive mass coral bleaching events, we may not see adaptation and recovery as an option for them.
Scientists predicted that up to 90% of coral reefs around the world may disappear in the next 20 years due to ocean acidification. The Great Barrier Reef is one of the reef areas most affected by acidification.
UNESCO scientists’ report argues that the Great Barrier Reef should be added to the list of world heritage sites that are “in danger.” This UN-backed recommendation comes after the World Heritage Committee’s initial recommendation of an “in danger” listing in 2021.
The report argues that in order to give the Great Barrier Reef a chance to combat the effects of ocean acidification, we must reduce greenhouse gas emissions, reassess carbon credit schemes and increase financial investment in protecting the reef.

What Was the Response to the UNESCO Report?

UNESCO’s push to list the Great Barrier Reef as “in danger” was received with a mixed response.

UNESCO advised the Australian government to boost its carbon-reduction policies and invest more in water-quality improvement programs. However, the Australian government’s policies continue to fall short of UNESCO’s critical recommendations.
The Australian government argues that it is unnecessary to list the Great Barrier Reef as “in danger” because they are doing enough to protect the Great Barrier Reef. For example, they cite their recent commitment to invest $1 billion in reef protection programs from 2022 to 2030.
While UNESCO acknowledges that listing the Great Barrier Reef as “in danger” could affect its tourism, it may also establish Australia’s name as a world leader in terms of the conservation and protection of a world heritage site.
UNESCO also emphasized that categorizing the Great Barrier Reef as “in danger” on the world heritage list is essential, as it could encourage other countries to join in conservation efforts to protect it. The World Heritage Committee’s decision whether to label the Great Barrier Reef as “in danger” or not will be based on UNESCO’s assessment. UNESCO is still waiting for Australia to ensure compliance with their provided recommendations. However, the Australian government continues to deny that these recommendations are necessary.

great barrier reef bleaching - great barrier reef in danger — Coral bleaching in the Great Barrier Reef (March 2022)
(Source: WWF Australia/ABC News)

Sources:

“Great Barrier Reef should be placed on the ‘in danger’ list, UN-backed report shows” CNN, Nov 29, 2022

https://www.sciencedaily.com/releases/2022/05/220525182619.htm

“United Nations recommends Great Barrier Reef be added to World Heritage ‘in danger’ list” ABC News, Nov 29, 2022

https://www.abc.net.au/news/2022-11-29/united-nations-queensland-great-barrier-reef-danger-report/101705908

“Report on the Joint World Heritage Centre/IUCN reactive monitoring mission to the Great Barrier Reef (Australia from 21 to 30 March 2022)” UNESCO, Nov 2022.

https://unesdoc.unesco.org/ark:/48223/pf0000383823

How Is Sunscreen Killing Coral Reefs?

Posted on September 7, 2022September 7, 2022 by Team Writer

sunscreen washing into ocean - reef safe sunscreen — Statistical source: Danovaro et al. 2008

Did you know that the sunscreen you apply doesn’t always stay on your skin? In fact, when we swim (or even shower), the sunscreen you’ve applied throughout the day washes off into waterways and often ends up in the ocean. In fact, around 6000 tons of sunscreen washes off into reef areas every year, according to scientists. That’s equal to the weight of nearly 50 blue whales!

While we depend on sunscreen to protect us from skin damage and disease, many sunscreens actually cause great harm to marine ecosystems. And with 80% of corals in the Caribbean lost in the last 50 years, in part due to pollution, it’s more important now than ever before to ensure we take steps to avoid damaging these important organisms further.

But how exactly does sunscreen damage coral reefs, and what can we do about it? Let’s dive in.

Protection for People, Harm to Marine Life

Researchers estimate that approximately 10%, if not more, of coral reefs around the world are threatened by sunscreen. The areas feeling the brunt of the damage are highly-tourested areas like Hawaii and the Caribbean, where thousands of tourists swim every day, leaving sunscreen behind them.

So, how is sunscreen killing coral reefs? There are two main types of sunscreen: physical and chemical. Unfortunately, both types of sunscreen can cause harm to coral and other types of marine life.

Physical sunscreen is made of minerals that sit on top of your skin and reflect the sun’s rays. The main minerals used for this purpose are titanium dioxide and zinc oxide, which can wash off into the water. In fact, studies estimate that the average tourists on a Mediterranean beach release 4kg of titanium dioxide in a single day. When these minerals are very small (called “nanoparticles”), they can be absorbed by coral and cause severe damage.

A 2018 study found that zinc oxide nanoparticles cause extreme coral bleaching. This is because the zinc interferes with symbiosis between coral and other organisms, which leads to bleaching over time. Zinc oxide and titanium dioxide nanoparticles in the ocean may also cause chemical reactions to occur that result in hydrogen peroxide, which bleaches coral.

Chemical sunscreens contain chemicals that absorb into the skin, and then absorb UV rays before they can hit your skin. The active ingredients include “UV filtering” chemicals avobenzone, octinoxate, and oxybenzone. These are extremely potent and toxic to marine animals including coral.

New Research: How Does Sunscreen Harm Coral Reefs?

While scientists have known that oxybenzone damages coral reefs for a while, they did not know exactly how the chemical was causing harm. In May 2022, researchers at Stanford released a study that explored oxybenzone’s effects on sea anemone, an organism that’s closely related to corals.

The researchers found that when oxybenzone was exposed to light and a sugar found in anemone tissue, not only did it kill the anemone, but the chemical metabolized into another molecule, releasing free radicals that kill coral. Sea anemones exposed to oxybenzone and sunlight died around one-three weeks after exposure.

Finally, preservatives used in sunscreen to help the product last longer can also have toxic effects on both humans and coral. For example, parabens, a class of preservatives, are used in many sunscreens to prevent the growth of bacteria and mold. However, parabens can wash off into the environment, and have been found in a wide variety of organisms all over the world, from fish to marine mammals and birds. Studies show that parabens can disrupt the hormones of a variety of animals, including humans.

Parabens can also cause viral infections in zooxanthellae, symbiotic algae that live in healthy coral tissue and provide it with nutrients. A 2008 study showed that, because of these viral infections, coral bleaching occurred within a few hours to a few days of exposure to even very small amounts of sunscreen.

Does Sunscreen Harm Other Types of Ecosystems?

It’s not just marine life that’s impacted by sunscreen. When we shower, sunscreen is often washed off into wastewater, which makes its way into fresh bodies of water. However, due to the extreme variety of aquatic ecosystems throughout the world, the specific impacts of sunscreen in aquatic environments are still unknown.

Many experts are calling for more research into the impacts of sunscreen on non-marine ecosystems. In August 2022, the National Academies of Sciences, Engineering and Medicine published a report calling on the US EPA to conduct further studies into the risks that UV filters cause to aquatic ecosystems (including freshwater). They explain that while we know UV filters have been found in water, sediment and even animal tissue in a variety of ecosystems, we need more information to understand the extent of the impacts they’re having on a variety of aquatic organisms.

Government attention to the issue of sunscreen killing coral reefs is not limited to scientific data gathering, however. Next, we’ll review how a few governments have taken a stab at protecting coral reefs and other marine organisms from toxic sunscreen ingredients.

Legislation: Bans on Reef-Toxic Sunscreen

In response to concerns about the toxic effects of sunscreen on coral reefs and the intense reduction in living coral reefs, several governments have passed legislation banning sunscreen containing oxybenzone and octinoxate.

Hawaii was the first state to ban harmful sunscreens with the passage of a bill in 2018 that banned oxybenzone and octinoxate sunscreens. In 2021, the Hawaii State Legislature passed another bill that banned two more harmful chemicals in sunscreen, avobenzone and octocrylene.

Other local and federal governments have also banned harmful sunscreens, including:

What You Can Do to Protect the Ocean from Harmful Sunscreen

There are a few things you can do to avoid putting more harmful sunscreen into the ocean.

1. Use other forms of sun protection. While sunscreen is, of course, a necessary product to protect ourselves from harmful ultraviolet rays, it should really be a last resort. Instead, use UV-protective clothing like a sun shirt to reduce the amount of sun your skin is exposed to. You can also try and spend time in the shade to protect your skin.

2. Use reef-safe sunscreen. When you do need to use sunscreen, make sure it’s a reef-safe sunscreen. First, avoid spray-on (aerosol) sunscreen, as the spray disperses into the environment much more easily than a cream, and often contains harmful chemicals. Instead, opt for a mineral sunscreen with zinc oxide and titanium dioxide that aren’t nanoparticles (if the packaging doesn’t explicitly say “micro-sized” or “non-nano,” you can be pretty sure it contains harmful nano-sized particles).

To figure out if a sunscreen is truly reef friendly, look at the label. Make sure to avoid these chemicals:

sunscreen coral reefs - reef safe sunscreen

Finally, while sunscreen in the ocean is clearly harming coral reefs, we must also take into consideration the other threats to coral reefs, including overfishing and climate change’s rising temperatures. Changing to a reef-safe sunscreen may make a small dent, but we must curb climate change in order to truly protect coral reefs and other marine life.

How Ocean Acidification Affects the Development of Several Marine Species

Posted on May 12, 2022June 9, 2022 by Team Writer

Rising ocean acidity is affecting the development of different types of marine species, such as sea urchins and brightly-colored reef fish.

A recent study shows how sea urchin development is affected by ocean acidification. (more…)

The Great Barrier Reef is experiencing massive coral bleaching events due to ocean acidification, which negatively affects the development of brightly-colored fish in the reef. (more…)

Background Information: What is Ocean Acidification?

Full Research: Direct and latent effects of ocean acidification on the transition of a sea urchin from planktonic larva to benthic juvenile, Are fish communities on coral reefs becoming less colorful?

Study Shows How Ocean Acidification Affects Sea Urchin Early Stage Development

Ocean acidification has a significant negative impact on marine species and ecosystems. A recent study shows how ocean acidification affects the early development stages of some marine species, such as sea urchins. Here’s what you need to know about it.

The study researched the effects of pH on sea urchin’s development and transition from fertilization to juveniles. The result shows that low pH levels significantly affected the growth and mortality of the urchin’s larval stage. Even small changes in ocean pH (on the scale of .1) can have major impacts.

Larval Stage: Effects of Ocean Acidification

Sea urchin larvae were exposed to a 7.2 pH level (compared to the current ocean’s actual pH of 8.1). The sea urchins exposed to this pH exhibited the following characteristics:
- Higher mortality rates.
- Higher abnormality rates.
- Lower growth rates.

The metabolism of sea urchin larvae exposed to a 7.2 pH level increased as well. The researchers believe that because of this, the urchins may be using additional energy to boost metabolic function, which might limit their growth rates. In other words, the sea urchins adapt to ocean acidification by shifting their energy to boost metabolic function, rather than other important functionalities. Researchers believe that this shift in energy may be what’s causing mortality and abnormalities throughout their development stages.

Settlement Stage

Researchers discovered that prolonged exposure to a 7.7 pH level significantly delayed the settlement of sea urchin larvae, an important process during which larvae settle to the ocean floor where they will eventually begin their adult life stages.
However, when the sea urchin larvae were placed under a suitable algal substrate for the settlement stage, the researchers found that the larvae remained unaffected by 7.7 pH levels. This shows that algae may help reduce the effects of ocean acidification on sea urchin larvae.

Metamorphosis Stage

The study shows that in the metamorphosis stage, all the sea urchins that were grown at a 7.2 pH level failed to metamorphose. The researchers concluded that sea urchins that are exposed to low pH levels throughout their early development stages may find it hard to impossible to achieve metamorphosis.

However, the study also shows that 30% of the sea urchin larvae that were grown at a 7.6 pH level achieved the metamorphosis stage. This shows the large impact of even a pH change of .4, compared to the 7.2 pH group of urchins.

sea urchin development - ocean acidification sea urchins — The development cycle of a sea urchin.
(Source: © Natural History Museum, London)

Ocean Acidification Affects Brightly-Colored Fish Development Through Continuous Coral Bleaching

The Great Barrier Reef is experiencing massive coral bleaching events due to ocean acidification, which negatively affects the development of fish’s color in the reef. Here’s all you need to know about the study.

In the span of just three decades, the effects of ocean acidification and global warming have caused the Great Barrier Reef to lose thousands of its coral species. This phenomenon is commonly known as massive coral bleaching events. As a result of this, the number of brightly-colored fish in the Great Barrier Reef is decreasing.

According to the study, the number of different types of brightly-colored fish in the Great Barrier Reef has declined significantly since the massive coral bleaching event of 1998. Scientists believe that the composition of the seafloor (texture, colors, patterns) affects the development of the coloration of fish.

Reef fishes developed coloration to protect themselves from predators by adapting to the different coral structures and compositions. Fish would find it useless to produce vibrant colorations in the absence of coral compositions.

The study concluded that the loss of vibrant composition and structure of the seafloor due to the massive coral bleaching events has a significant relationship to the inability of many fish to develop their vibrant colors.

coral bleaching in great barrier reef — 6^th massive coral bleaching event in the Great Barrier Reef (2022).
(Source: © Earth.org)

Sources:

“Direct and latent effects of ocean acidification on the transition of a sea urchin from planktonic larva to benthic juvenile” Nature, April 01, 2022

https://www.nature.com/articles/s41598-022-09537-7

“Fish on Australia’s Great Barrier Reef are losing their colour as corals die” Independent UK, March 23, 2022

https://www.independent.co.uk/climate-change/news/great-barrier-reef-australia-fish-colour-b2041887.html

An Ocean Acidification Case Study: How Coral Reefs in the Pacific Basin Are Impacted by Ocean Acidification

Posted on May 10, 2022May 25, 2022 by Team Writer

Ocean acidification occurs when the pH level of seawater decreases. This is most frequently caused by the ocean absorbing excess CO₂ from the atmosphere. By evaluating an ocean acidification case study, we can get a sense of how damaging ocean acidification currently is, and what measures can be implemented to prevent further damage.

This article will outline a case study on how ocean acidification affects coral reefs in the Pacific Basin, as well as proposed solutions to prevent further damage.

Background Information: Ocean Acidification Infographic

About the Case Study

This study, Lebrec et al. 2019, was originally published in the journal “Regional Studies in Marine Science.” It discusses the effects of ocean acidification on coral reefs in the Pacific Basin, where mass coral bleaching has occurred. The case study highlights five coral reef ecosystems in the Pacific basin, which are found in the following locations:

Ryukyu Archipelago, Japan
Palau
Hawaii
Marshall Islands
American Samoa

coral reef ecosystems map - coral ocean acidification — *Locations of coral reef ecosystems highlighted for the case study*
*Source:* *Lebrec et al. 2019*

The case study evaluates the impact of ocean acidification on the above locations and proposes solutions to prevent ocean acidification and other ocean stressors from causing further damage to coral reefs.

Source: Ocean acidification impacts in select Pacific Basin coral reef ecosystems

Main Takeaways

Here are the main takeaways from the case study:

Ocean acidification negatively affects the coral reefs in the Pacific Basin by reducing the amount of calcium carbonate that is essential to coral reef skeletal development and coral survival. This causes coral reef death.

The study highlights the importance of unique coral diversity in each of the five geographic locations, as well as the vital role coral reefs play in local communities and economies.
1. Hawaiian coral reefs are not just important to the tourism industry, but they also provide direct benefits to the community by sustaining fisheries and pharmaceutical production, which generate income through exportations. Hawaiian coral reefs also provide indirect benefits to the community by protecting coastal areas from storms. The economic value of coral reefs in Hawaii is about $455 million USD.
2. The Marshall Islands is the world’s most coral reef-dependent country. Most of their needs are met by the reef, including employment, nutrition, exportation, tourism, and protection against natural disasters.
3. The Ryukyu Archipelago is home to more than 360 species of corals, which makes it the world’s richest endemic coral reef. The archipelago’s coral reef plays an important role in its economy, generating $4.7 billion USD tourism revenue in a single year.
4. Palau is home to around 425 species of coral reef, which makes the country the most biodiverse coral reef in all of Micronesia. It provides 40% of the country’s employment, as over 90% of tourists that visit the island come for diving and snorkeling.
5. American Samoa is home to about 200 coral reef species, which is why the government established 6 major protected areas for coral reefs across the archipelago.

The locations in the case study are experiencing coral bleaching events due to the combined effects of different disasters, pollution, and ocean acidification. This affects these countries since all of them rely heavily on the services that coral reefs provide.
1. Hawaiian coral reefs are bleaching as a result of rising temperatures and ocean acidification, and certain coral reef species are recovering at a slower rate than expected.
2. Increasing temperatures have bleached over 90% of the coral reefs of Okinawa Island, which is part of the Ryukyu archipelago.
3. From 1997 to 1998, Palau had a GDP decline of about 3.3% due to intense coral bleaching events.

coral bleaching - ocean acidification — *Coral reef bleaching in Airport reef, Tutuila, American Samoa*
*Source:* *Coral Reef Watch/NOAA*

Proposed Solutions to Fight Ocean Acidification-Related Bleaching

This case study provides 3 proposed solutions to fight ocean acidification and its damage to the coral reefs in the Pacific basin.

Adaptation promotes the resilience of coral reefs by initiating conservation regulations and the reforestation of coral reefs, and increasing coral reef protected areas.
Mitigation covers the reduction of carbon emissions at the global and local scales. This could be in the form of carbon taxation, an emissions trading system, or a cap-and-trade system.
Capacity Building focuses on promoting local research advancements and spreading education and awareness to the community, generating funds to improve coral reef conservation efforts, and creating local collaborative efforts to promote national policies that push for unified international policies.

Conclusions

This case study highlights the importance of coral reefs in the Pacific Basin and how the countries around it majorly depend on the services that the coral reefs provide. Understanding the impacts of ocean acidification on coral reefs in the Pacific basin can help us promote solutions to ensure their benefits to humans and ecosystems remain intact.

This case study is just a part of a much larger global issue of ocean acidification and its negative effects. There are many other countries around the world that are experiencing not only coral reef bleaching but also damage to marine animals and microorganisms that are essential to maintaining the ecological balance of the world. The case study emphasizes the importance of addressing ocean acidification, as if we fail, people all over the world will lose sources of food, income, and culture.