BLEACHED REEFS IN THE PACIFIC
MASS BLEACHING x 2
As we process the horrific news that 25% of the Great Barrier Reef has bleached last week—only about half of which is expected to survive—I feel compelled to share my experience viewing reef in Fiji was similarly heart breaking.
I was excited to dive amongst the rainbow reefs, but instead saw beds & bushels of snow white coral.
In February, in addition to sustaining damage from the cyclone, Fijian coral reefs also experienced mass bleaching as the sea temperature rose to record heights. The cyclone and sea temperature change are both a result of the climatic changes brought on by our current El Nino cycle. Out in the reef flats the water peaked at 36 degrees celsius, and because the temperature is remaining at a steamy 30 degrees, recovery for most coral is unlikely. Even deeper water coral is showing signs of thermal stress!
Coral cannot survive long after bleaching. Coral lives a symbiotic life, which means they live with other organisms to benefit each other. Most reef-building corals have a mutually beneficial relationship with a microscopic algae (zooxanthellae) that lives within the cells of the coral. The coral provides the algae with a protected environment and the compounds necessary for photosynthesis (essentially coral’s waste products). In return, the algae produce oxygen and help remove the coral’s waste. Most importantly, they supply the coral with organic products of photosynthesis which are predominantly carbohydrates aka the building blocks of their calcium carbonate skeletons. Both critically rely on one another to survive.
The high temperatures kill the coral’s symbiotic algae that live inside, and they bleach—or turn white—because another byproduct of the symbiotic relationship with zooxanthellae is colour. Coral tissue itself is mostly transparent and their calcium carbonate skeletons are white. Whereas, several million zooxanthellae live and produce pigments in just one square inch of coral.
If the sea stays hot, the coral will die, because they will not be able to restore and support the algae within. If the sea cools, the coral has a chance of recovery, but still it is a struggle. The post-cyclone temperature has dropped a couple of degrees and now ranges from 27-28°C, which if continues will help corals return to normal. However, many of the corals in both mass bleaching have already perished. (http://coralreef.noaa.gov/aboutcorals/coral101/symbioticalgae/)
FISH BOILED IN THE WATER
The other mental thing that happened as a result of the seas heating up, THE FISH BOILED. Literally thousands (yes, thousands) of fish washed up on the beach COOKED. What happens is on the reef flats when the tide goes down, the shallow water really heats up and the fish have died because of the lack oxygen. I was not there during this time, but there was a day I stood in ankle deep water & the sea was so hot, my legs felt like they were burning. I cannot imagine having to live in that.
Locals were actually eating the dead fish and the government had to issue warnings to the villages to stop eating the ocean boiled seafood. This is understandable as our oceans are already over-fished. What once was an abundant food source, is being decimated by mi managed fisheries. But this is another topic…
Dead coral, dead fish, but the hope lives. The ocean is a powerful host to much life and will fight to restore the vibrance within. We humans, with our ocean hobbies and framed beach pics, must step up and make drastic change sooner than later. It’s easy to say, but for some reason we struggle to do.
Two mass bleachings of the world’s most pristine and prized coral reefs in the past two months. Dead fish washing up on beaches. What do we need to fight this?