Coral bleaching on the Great Barrier Reef has been making headlines around the world again! This year (2017) more bleaching is being observed around the central part of the Reef (Cairns to Townsville), which last year escaped the severe bleaching event. In 2016 it was the northern parts of the Great Barrier Reef that underwent mass coral bleaching.
Bleaching is caused by rising sea temperatures. The coral stresses, starves and stops producing the pigments that make the colour. If the coral becomes really stressed they reject the algae as well. If things do not get better (ie the sea becomes cooler) the corals may then die.
The good news is that coral CAN recover if normal conditions return.
Many scientists have blamed Global Warming as the cause behind the bleaching and are trying to get governments, and the world to respond to this threat. You’ve probably noticed some BIG headlines lately in the news.
Here’s a recent video of people’s experiences on the reef.
In Australia, summer is coming to an end and as the sea temperatures drop there will be less stress on the coral. In Cairns there has been some stress and dimming of colour, but as conditions improve the coral should be able to bounce back.
People may see some bleaching but as far as we know the reefs offshore from Cairns and Port Douglas are fine. The best news is that as we move into lower water temperatures the affected corals will start to recover with minimal mortality.
AND to celebrate the true awesomeness of the Great Barrier Reef I thought I’d share 36 other Great Barrier Reef Facts that you may not already know.
This FUN list on the Great Barrier Reef Facts (and the information above) has been compiled by David Witherall, a Marine Biologist who’s ‘office’ is on the reef just off Cairns. David is also the driving force behind the Naiad Project, which invites people to become guardians of the reef. Click HERE to learn about David’s work – The Naiad Project.
Back when Woolly Mammoths and cavemen were walking around Europe (about 12, 000 years ago), you could walk to where the reef is now.
The first Great Barrier Reef dried up and regrew dozens of times (every time there was an ice age).
To put this into perspective the United Kingdom is 242,495 km² ( a bit smaller).
The Great Barrier Reef is so extensive because a mountain Range as big as the Andes slowly eroded away and formed a huge shallow area off the coast (The Great Dividing Range on the Australian mainland is all that is left of this enormous range).
Corals are really very small upside-down jellyfish called polyps (the smallest is 1mm the largest is 15cm).
At 1mm in size there would be 10 million per square kilometre, or 3.444 trillion on the Great Barrier Reef (or if the average polyp is a word then about 49 million books).
Corals have plants (or algae) in their skin, in the cells of their skin called Zooxanthallae.
This algae (zooxanthallae) gets energy from the sun and gives it to the coral. The coral gets more than 90% of the energy they need from this algae (This is like you eating your vegies and then turning green and living off sunshine and an apple a day).
These bones can be as big as a room (a small room with no wardrobe).
When ready, corals grow a brother or sister out of their body (usually between the tentacles) and they stay connected even after their sibling grows their own room.
More and more brothers or sisters are made, more rooms are added until eventually houses grow up and form buildings and we call these buildings, coral.
Corals need sun so they grow on top of each other, as the sea level rises so does the coral and really deep coral pinnacles may have started growing 1000’s of years ago (so when you are at the bottom of one think about The Romans and Gladiators and Aphrodite the Goddess of Love).
The oldest living creature may be the Barrel Sponge, a big one probably started growing when the Vikings were raiding England’s monasteries.
The Barrier Reef roughly forms a broken line where the Australian Coast would have been during an Ice Age, and 100’s of smaller scattered reefs that would have been hills.
There are around 3000 coral reefs, 600 continental islands, 300 coral cays and about 150 inshore mangrove islands. PLUS there are about 6000 different animal species on the Great Barrier Reef (600 corals, 1625 fish).
The biggest current damage to the Reef at the moment is from pollution; a slow and subtle shift in the quality of water which stresses the coral. It is what people do on land; cutting down trees, fertilising crops, polluting and changing the flow of the water that damages the reef the most.
The most fantasy-world-like swimmer is the feather star (it is like watching a scene from a movie where a magician makes a flower fly). It paddles its arms up and down in groups of four.
The most alien-looking creatures you can’t see but you can see the fish eating them: plankton that look like commas, fairies, alien spaceships or hairy swimming beans.
At night a whole bunch of plankton migrate from the depths to feed on the stuff that grew during the day, a whole bunch of reddish or see-through fish with big eyes come out to feed on them (as well as a whole bunch of crabs, snails, worms and sea stars that come out to feed under the cover of darkness), and a whole bunch of sharks, eels and octopus come out to feed on them (and on each other).
Some fish will actually cover their body in mucous (which is snot) to hide (and then eat it in the morning), others will change colour (or put on their dark pyjamas).
Lots of fish not only change colour, they change personality (usually becoming bossy) and change from a woman to a man. They do this because they can (or in Nemo’s case, because women are better (women grow eggs)).
Fish have a muscle that vibrates inside them, which hammers a rib bone into their swim bladder and makes a drum beat. Different rhythms have different meanings (danger, go away, I love you) and so they can talk to each other without moving their mouths.
To survive, a fish remembers the smells before it was attacked, or before another fish was attacked or before another fish drummed out a warning call. Old fish are more likely to survive because they have a good smell memory.
The complicated term ‘Intermediate Disturbance Hypothesis’ explains that without disturbance a dominant species of coral would take over, a storm or other disturbance will knock down these dominant species and make space for all the others (it would be good if cyclones did this with school bullies).
This means that the Australian and 182 other Governments have agreed to ‘ensure that effective and active measures are taken for (its) protection, conservation and presentation’ and that even during a war ‘no country should damage’ it.
The Aboriginal people have passed on stories that date back to the time when the sea level was so low that the inner reefs were limestone hills. There is one legend that the Seagull Woman dragged the land away so the Ocean flooded in and there are many other stories of dreamtime spirits becoming the islands and animals we see today (Lizard Island was a Stingray, and triggerfish and the Giant Trevally were once a mother and son).
What is considered the most incredible cell on Earth is in the skin of coral and jellyfish. The cnidocyte is a single cell that has about 200 times the pressure of the atmosphere inside of it (we need metal tanks to contain such pressure). This pressure explodes out a venomous hook or net into whatever triggers it.
Corals, sponges and other reef creatures contain toxins to protect them from getting eaten. These toxins are being used to cure diseases such as HIV and Cancer.
The most famous quote from Finding Nemo is; “just keep swimming” – Dory.
Six of the world’s seven species of sea turtles breed here.
Rock-building algae contribute at least a third of the foundation and more importantly they glue coral rubble together and will do so where the waves are crashing and corals cannot grow.
Other Algae are not so good for coral and would smother coral if it weren’t for algae-eating superheroes like Batfish (which has been named the single best algae-fighting species in Gotham (I mean the Great Barrier Reef).
Sea Cucumbers eat sand (so what! you might say). When they eat the sand, they dissolve it and set free the Calcium molecule that the reefs need. Taking away the Sea Cucumbers would be like taking away the worms; the trees would fall over, the air would become stale and not even Batfish could save us.
Crown of thorns Starfish spew out their stomach so that it flows into the gaps of the coral branches, slowly digest all the flesh and then suck their stomach back up.
There have been plagues of Crown of Thorns Starfish that have eaten up to 90% of the coral on a part of the reef and then walked away, travelled along the bottom and gone to the next reef.
When you walk through a limestone cave with stalactites and stalgmites you are probably walking through what was once an Ancient coral reef (one day people will do tours through caves that were the Great Barrier Reef, Tour Guides will say ‘and here is the fossilised remains of what was once Dave’s brand new dive mask’.
Facts & Images supplied by David Witherall, BSc (unless otherwise credited)
Hopefully David’s mask won’t become a fossil and hopefully you’ll remember one or two of these amazing Great Barrier Reef Facts and impress your friends next time you here a news report on the reef.
And remember, the coral around the Cairns region is looking good, so good in fact that I may have to go out with my family for another adventure soon…….
Click Below to read some of our favourite Family Adventures on the Great Barrier Reef:
Have you been out on the Great Barrier Reef lately? What adventures did you get up to? What was the coolest thing you saw on the reef?