The post UNESCO Scientists Explain Why the Great Barrier Reef Is in Danger: New Report appeared first on Ocean Acidification.
]]>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)
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.
UNESCO’s push to list the Great Barrier Reef as “in danger” was received with a mixed response.
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
“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
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]]>The post How Is Sunscreen Killing Coral Reefs? appeared first on Ocean Acidification.
]]>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.
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.
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.
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.
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:
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:
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.
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]]>The post How Ocean Acidification Affects the Development of Several Marine Species appeared first on Ocean Acidification.
]]>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?
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
Settlement Stage
Metamorphosis Stage
Read more: How Ocean Acidification Affects Sea Urchins
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.
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
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