8/7/2020 What's Happening Seeing colorful bright coral has become a rare sight. White and brown corals have become more common, and though white corals may look gorgeous, they're actually in a state of starvation. Brown corals are already dead or on the verge of death with no possibility of survival. When you look at the white and brown corals, it's important to remember that the loss of color has effects beyond the corals themselves. Corals support over 25% of marine wildlife and bring $3.4 billion into the economy each year. They save $94 million by preventing extensive flood damage each year. They are a remarkable species.
Corals have a mutualistic relationship with zooxanthellae, which is a photosynthetic algae. Zooxanthellae live in the coral's tissues and can produce and supply the coral with glucose, glycerol, and amino acids through photosynthesis. These are essential for the coral to survive because it helps the coral produce carbohydrates, calcium carbonate, proteins, and fats. For corals to thrive, they need Zooxanthellae in their polyps (individual corals), as they receive 90% of their energy from the algae. You can find corals with a range of vibrant colors that countless people will travel just to see. Zooxanthellae produce these vibrant colors. Without Zooxanthellae, corals cannot survive, and they will be colorless. The white color corals are considered "bleached" corals. When corals become stressed, they expel algae, losing their primary source of energy and color, resulting in coral bleaching. Corals become stressed when the water isn't clear enough to receive sufficient amounts of light, when water temperatures increase, or when they don't receive enough nutrients. Bleached corals are usually mistaken as dead; however, they are still alive and have a chance of surviving. Yet, since they are stressed, they have a higher chance of mortality. Not all bleachings are due to warm ocean temperatures, but global warming underlies the warmer temperatures causing most coral bleaching events. Coral bleaching is not a new problem. There just hasn't been much done to stop it. The first mass coral bleaching event took place in 1983, and there was a terrifying bleaching event in 1998. The Caribbean lost half of its coral reefs in 2005 as a result of extreme thermal stress. In 2010, there was another round of extensive thermal stress which caused a large bleaching event. 2016 and 1988 had the worst bleachings recorded. Scientists recorded the bleaching changes between 2016 and 2020 and noticed a significant difference. In the past (2016), only several reefs were severely bleached; however, now in 2020, there's widespread bleaching. In such a short time, 25% of the reefs have become completely bleached, which will end with the majority of them dying. By 2050, 90% of the coral reefs will be dead. This calls for demanded help. Corals support human life and marine life. Humans have relied on corals for countless years, and now the corals are relying on us for our help. https://coralreef.noaa.gov/ Comments are closed.
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