Desperate situations call for desperate measures as scientists take extreme steps to help corals survive. They are resorting to selective coral breeding by fertilizing, transplanting, and enhancing the dying corals. They are hopeful that this will help them adapt to the rising ocean temperatures. but using this technique to rebuild entire reefs could prove daunting.
The warming of the seas and oceans is destroying the world’s coral reefs, with even the Great Barrier Reef heavily under threat. The thriving underwater sea life has all but disappeared. The clams, cuttlefish, and turtles are nowhere around. And the coral has turned drab, the thriving colony replaced by sediment and algae.
Corals comprise living animal tissue that is often mistaken for rocks. The microscopic algae living inside provide it with food and impart color. But rising ocean temperatures are stressing the corals, causing them to expel the algae. The tissue bleach, starve and die.
We have already lost half of the coral reefs in the past 30 years. By 2050, we could lose 90% according to the Intergovernmental Panel on Climate Change. The reefs support a quarter of all marine species that cover a mere 0.1% of the ocean floor.
Selective Coral Breeding Could Save The Coral
Scientists are going in for creative ways given the urgency of the situation. One of the solutions being actively pursued is selective coral breeding. It is hoped to become a lifeline for the corals and help them survive temperatures to which they were previously vulnerable. Studies showed that some were able to withstand temperatures reaching up to 36C (96.8F).
Scientists believe that selective coral breeding over one generation could make the coral resistant to abnormally high temperatures, something that all ocean lifeforms may have to withstand to survive the global rise in ocean temperatures.
Science Advances published the research, which showed that coral sourced from among the hottest seasons on the planet can impart beneficial genes that could transfer genes that would make the offspring more tolerant to heat. This would work even when they are crossed with corals selected from cooler waters.
Various coral varieties can survive in high temperatures and not get stressed or die out. For instance, corals in the warm Persian Gulf are adapted genetically to high water temperatures. They can withstand summer temperatures as high as 34C even for weeks, and a daily average of 36C.
These water regions have temperatures that are 2C to 4C higher than other regions where corals thrive. Even more significant, these temperatures match the projected rise in water temperature in the oceans at the end of the century in coral reefs outside the Gulf.
Researchers collected fragments from the Platygyra daedalea corals found in the Gulf, crossbreeding them with varieties of similar species surviving in the waters of the colder Indian Ocean.
The resulting offspring from the union were heat-stressed. Over 12,000 individual larvae of corals were subjected to high temperatures of between 33C and 36C; the summer maximum temperatures to which the two varieties are subjected in natural circumstances.
Selective Coral Breeding Delivers Positive Results
The results were extremely encouraging as gene variants linked to heat tolerance weren’t limited to the corals sourced from the Persian Gulf.
The Indian Ocean parents also produced offspring that had a high rate of survival under hot conditions. Their tolerance level matched that of gene variants found in the Persian Gulf.
This encouraging result in selective coral breeding suggests that certain populations have variations in their genes that can allow them to withstand rising ocean temperatures.
Researchers are in the process of finding out the gene variants that are heat tolerant and how such variants are spread within and among the reefs. The answers from this research should help researchers find a way to save the corals of the Great Barrier Reef.
Saving the coral will require a drive along many fronts. While selective coral breeding will provide some respite to particular variants of the corals, but it will not work for the entire population. The solution lies in reducing the rising temperatures and prevent drastic climate change.