Evolutionary secrets help Red Sea corals withstand heat
What is in news?
- In the azure waters of the Red Sea, Maoz Fine and his team dive to study what may be the planet’s most unique coral: one that can survive global warming, at least for now.
- The corals, striking in their red, orange and green colours, grow on tables some eight metres underwater, put there by the Israeli scientists to unlock their secrets to survival.
- They are of the same species that grows elsewhere in the northern Red Sea and are resistant to high temperatures.
- Global warming has in recent years caused colourful coral reefs to bleach and die around the world — but not in the Gulf of Eilat, or Aqaba, part of the northern Red Sea. That is what has prompted Mr. Fine’s work, both in the Red Sea and on its shores.
- According to Mr. Fine, the Gulf of Eilat corals fare well in heat thanks to their slow journey from the Indian Ocean through the Bab al-Mandab Strait, between Djibouti and Yemen, where water temperatures are much higher.
“Over the past 6,000 years, they underwent a form of selection through a very, very hot body of water, and only those that could pass through that hot water body reached here, the northern Red Sea and Gulf of Eilat.
About Red sea:
The Red Sea (also the Erythraean Sea) is a seawater inlet of the Indian Ocean, lying between Africa and Asia.
The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. To the north lie the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez (leading to the Suez Canal).
The Red Sea is a Global 200 ecoregion.
The sea is underlain by the Red Sea Rift which is part of the Great Rift Valley.
The six countries bordering the Red Sea proper are:
Eastern shore: Saudi Arabia. Yemen.
Western shore: Egypt. Sudan. Eritrea. Djibou
- Corals are marine invertebrates in the class Anthozoa of phylum Cnidaria.
- They typically live in compact colonies of many identical individual polyps.
- The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.
- A coral “group” is a colony of myriad genetically identical polyps.
- Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in length.
- A set of tentacles surround a central mouth opening. An exoskeleton is excreted near the base. Over many generations, the colony thus creates a large skeleton that is characteristic of the species.
- Individual heads grow by asexual reproduction of polyps. Corals also breed sexually by spawning: polyps of the same species release gametes simultaneously over a period of one to several nights around a full moon.
- Although some corals can catch small fish and plankton using stinging cells on their tentacles, most corals obtain the majority of their energy and nutrients from photosynthetic unicellular dinoflagellates in the genus Symbiodinium that live within their tissues. These are commonly known as zooxanthellae and the corals that contain them are zooxanthellate corals.
- Such corals require sunlight and grow in clear, shallow water, typically at depths shallower than 60 metres (200 ft). Corals are major contributors to the physical structure of the coral reefs that develop in tropical and subtropical waters, such as the enormous Great Barrier Reef off the coast of Queensland, Australia.
- Other corals do not rely on zooxanthellae and can live in much deeper water, with the cold-water genus Lophelia surviving as deep as 3,000 metres (9,800 ft).
- Some have been found on the Darwin Mounds, north-west of Cape Wrath, Scotland. Corals have also been found as far north as off the coast of Washington State and the Aleutian Islands.