There is news recently that many tourist attractions famous for their coral reefs, such as the Great Barrier Reef on the east coast of Australia, have been affected by coral bleaching to varying degrees. A report drafted by the IPCC even mentioned that coral bleaching on the Great Barrier Reef has occurred every year since then. By 2030, the Great Barrier Reef's corals will be close to destruction. At the same time, scientists have also discovered large-scale coral bleaching in the Indian Ocean. We know that under normal circumstances, corals show a variety of different colors such as green, blue, yellow, brown, red, and purple, but these colors are not unique to the coral itself. , but from the symbiotic algae inside the coral.
Coral bleaching is a condition in which corals turn white. In the cultivation of ordinary corals, we will also encounter different levels of coral bleaching. When the ordinary colorful corals become no longer so beautiful, can we clearly see the essence of the problem and not blindly fear, then the coral What is going on with albinism?
Simply put, coral bleaching refers to the phenomenon of colorful corals fading and turning white. Under normal circumstances, the reason why corals show different colors is mainly due to the contribution of symbiotic algae. In addition to making corals beautiful, these symbiotic algae also use photosynthesis to produce the nutrients they and their host corals need to survive. When the seawater environment changes, especially when the water temperature is too high or the sun is too strong, corals will expel these symbiotic algae out of the body. The result is that the coral develops its own white color and loses its source of nutrients. If the external environmental change does not last long, after returning to the original conditions, the number of symbiotic algae in the coral will decrease again, and the coral will return to its original colorful pattern.
Coral bleaching phenomenon
However, it should be noted that although under normal circumstances, bleached corals have certain recovery ability, but this is when the environmental change is not too drastic and the whitening does not last for a long time. Once the environment changes too drastically or the bleaching lasts for too long, the bleached coral polyps will die because they are not adapted to the new environment or due to lack of nutrient supply for too long. Even if it returns to its original state at this time, the damaged coral cannot be restored. Naturally, different corals have different sensitivity to changes in the external environment. Some may be sensitive to environmental changes.Some have stronger ability to adapt to changes, and some will die when strong changes occur.
There are many reasons that may cause coral bleaching, such as: rising temperature, reduced solar radiation intensity, changes in the chemical properties of seawater, reduced seawater transparency, etc. Among the many causes, related to human activities, and the most important one that can lead to large-scale coral bleaching is a topic that everyone is more concerned about-global warming.
Global warming causes ocean temperatures to rise. As ocean temperatures continue to rise, the algae that corals rely on shrinks, making corals more susceptible to the effects of bleaching. Corals have a symbiotic relationship with the weak algae in their structures. They not only give the corals their beautiful color, but also provide them with most of the energy they need. When the seawater temperature rises too high, the coexistence between corals and algae is broken, and the corals will eliminate the algae and turn white. If this happens, the corals will lose energy and die.
So will coral reefs disappear? Scientists have discovered that zooxanthellae have the characteristic of adapting to environmental changes by changing genetic patterns. It is expected that coral reefs have potential adaptability and recovery mechanisms to climate warming, so coral reefs will not eventually disappear due to global warming.
Coral reefs, as "rainforests" in the ocean, have the most diverse ecosystems on earth. When coral bleaching continues, the entire coral reef ecosystem will be greatly harmed, and its productivity and diversity will be affected. The population numbers of invertebrates, fish, etc. living in it will be significantly reduced. At the same time, this will also bring huge economic damage to mankind. It is difficult to imagine how attractive coral reefs with no color and no beautiful fish swimming around will be for us aquarium enthusiasts.
Therefore, if we want to slow down the problem of coral bleaching, we can only prevent global warming, develop new energy sources, significantly reduce greenhouse gas emissions and slow down global change. Warmly, scientists have been conducting intensive research on coral bleaching in recent years. It is believed that new developments in coral reef bleaching research will have an important and long-term impact on the sustainable development of global coral reef ecological construction, ecological prevention and promotion.
</p>
</p>