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Coral Reef Awareness Week, held annually during the third week of July, was created to highlight the importance of coral reefs and the need to protect them. Coral reefs only cover 0.2% of the ocean floor, but these amazing ecosystems support about 2 million species of plants and marine animals. In addition, more than 500 million people around the world rely on coral reefs for food and income.
Coral reefs have been on the land for about 500 million years. But in recent decades, coral reefs are dying at an alarming rate. It is estimated that 19% of the world's coral reefs are already dead and 60% are currently threatened. If no global action is taken to stop this decline, all coral reefs will be threatened by 2050.
You may have heard about the toxicity of sunscreen for coral reefs, but many other factors also affect the health of coral reefs. Let's look at some of the worst threats facing coral reefs
1. Climate Change
Research suggests that climate change is rapidly becoming the most important threat to coral reefs today.
A coral reef is actually a community of hundreds to thousands of corals, which are easily disturbed by animals. changes in their environment. Each small soft coral secretes a hard outer limestone skeleton for protection. The accumulation of these skeletons creates a coral reef.
This process has continued uninterrupted for thousands of years and has created massive coral structures that we know today. But corals also form an incredible partnership with a type of algae known as zooxanthellae for this cycle to continue. Zooxanthellae are unicellular algae that can live in the soft tissues of corals, where they are photosynthesized in the same way as plants. Corals can then feed on the products of photosynthesis of algae and continue to grow and thrive.
It has been observed that an elevation of the ocean temperature of only one or two degrees can disrupt this unique partnership. When seawater warms, zooxanthellae begin to produce toxins, forcing corals to reject algae in the ocean. Without zooxanthellae corals lose a vital source of food and die slowly. This process is known as "bleaching" of the corals because the colorful and living algae and corals are gone, leaving behind only the skeletons of white limestone.
Climate change is driving an increase in global ocean temperatures. temperature peaks. A scary example of this was an unusually hot, 10-month stretch of water around Christmas Island in the Indian Ocean from July 2015 to April 2016. In the months following the peak of temperature , 90% of coral reef died
killer trend fueled by climate change is the ocean acidification. Every day, 90 million tons of carbon pollution are released into our atmosphere. About a third of this carbon is absorbed by our oceans, which progressively changes the chemistry of seawater and makes it more acidic. Chemical changes make it more difficult for corals to acquire the nutrients they need to survive, causing a slower decline than bleaching, but with such a deadly end.
2. Overfishing
World demand for fish continues to increase, both for food and for the pet trade. Overexploitation of fisheries resources to meet this demand weighs heavily on biodiversity and the ecological balance of coral reefs. Physically damaging fishing methods, such as trawling or the use of dynamite or cyanide in the water, can also damage or completely destroy coral reefs.
3. Pollution
Pollution affects our entire planet, including our oceans. A 2013 study found that airborne fine particles, largely produced by human industrial activities, effectively prevent sunlight from reaching corals, which has an impact on photosynthesis and growth. The researchers examined coral reefs in Panama and Belize and found that their growth rate had slowed since the 1950s because of this reduction in sunlight.
In addition, the 8 million tons of plastic that enter oceans every year in marine plants and animals, including corals, who eat tiny pieces of plastic thinking that they are food. Many other sources of pollution, such as oil spills, sewage and agricultural run-off, also weigh on coral reefs.
4. Human Activities
Irresponsible human recreation, such as nonchalance, snorkeling or diving, can damage coral reefs. Recreational boating can also affect coral reefs due to noise pollution, anchoring on sensitive areas or collisions with wildlife.
Human coastal development is another threat. Sensitive marine areas are dredged and disturbed to build airports and buildings on land reclaimed from the sea. In addition, the construction of marinas, fish farms and other water-based structures can disturb neighboring coral reefs.
5. Disease
The frequency of coral diseases appears to increase, mainly because of infection by bacteria, fungi or viruses. Scientists believe that this is largely due to the increased environmental and physical impacts that corals are currently experiencing, weakening their natural defenses.
For example, an Australian study examined the effect of permanent offshore visitor platforms built in the Great Barrier Reef. Reef Marine Park. The researchers found that coral disease was up to 18 times more likely in reefs with platforms compared to undisturbed reefs.
WHAT YOU CAN DO TO HELP THE CORAL REEFS
The World Resources Institute has an excellent video summarizing their reefs. Risk report, which examined the state of the world's coral reefs and what we can do to bring them back to health. Discover it below.
Narrated about Care2
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