The bulk of Earth’s coral reefs are in a very sorry state. In fact, if current climate trends continue, there’s a very real risk that your grandkids will grow up in a world without any coral reefs at all. But in the waters off the coast of Hawaii, scientists have recently discovered a collection of corals that aren’t going down without a fight.
A new study has documented the discovery of “super corals” that appear to have adapted to the harsh inhospitable waters in Hawaii’s Kāne'ohe Bay. While the battle is far from won, the marine biologists who discovered the reef say it “offers hope for reef resilience and effective conservation over coming decades.”
Reporting in the journal Proceedings of the Royal Society B: Biological Sciences, marine biologists at the University of Hawai‘i have noted that the coral reefs of Kāne'ohe Bay were devastated by human activity from the 1930s to 1970s. Along with being pummeled by sewage and pollution, the waters were also subjected to warming temperatures and ocean acidification. This culminated in up to 95 percent of the reefs suffering from catastrophic bleaching and damage. Then, in the late 1970s, the situation started to ease up when sewage outfalls were recollected away from the reef. Within just 20 years, parts of the reef had recovered by 50 to 90 percent.
Typically, as we’ve regularly seen elsewhere in the world, this level of stress is enough to spark widespread bleaching events so severe the coral reefs can’t recover. However, in Kāne'ohe Bay, numerous species of coral appear to have gained a tolerance to the acidic warmer waters and are bouncing back strongly.
To dive deeper in this phenomenon, they took colonies of coral from Kāne’ohe Bay and another reef in Waimānalo Bay, around 18 kilometers (11 miles) away, and compared how they fared against harsh waters under lab conditions. After living in a tank for 2.5 months with unfavorable water conditions, the Kāne’ohe Bay corals were notably more resilient and grew more than twice as fast as the Waimānalo Bay corals.
It appears that this isn’t just a short-term adaptation either. “The question now becomes, what mechanisms allow corals in these locations to show increased temperature and pH tolerance? Although our experiments in Kāne‘ohe Bay seem to rule out short-term acclimatization, the mechanism remains unknown," the authors wrote in the study.
It is too soon to say how common "super corals" are elsewhere in the world, nor whether they could recolonize devastated reefs in other parts of the planet. Nevertheless, the research shows that there is still hope for the world’s struggling reefs.
"If we take the necessary steps now then we will begin to see this re-establishment by corals during our lifetime, and our children and grandchildren will be able to witness the recovery of coral reefs during theirs because we make the decision that reefs are worth saving," study author Christopher P. Jury, Hawai‘i Institute of Marine Biology at the University of Hawai‘i at Mānoa, told AFP News Agency.