Great Barrier Reef (Day 88)
The Great Barrier Reef is like a secret hidden world, full of fish and amazing corals. There is so much to see under the sea!
The Great Barrier Reef is the biggest reef system in the world. There are 2,900 reefs and 900 islands over an area about the size as Japan. It is so big that you can see it from outer space! It is the largest structure made by living organisms. 10 percent of all the world’s coral reefs are here in the Great Barrier Reef.
We scuba dove and snorkeled at many spots, from the outer reef to the inner reef. Some of the best spots were simply found snorkeling near our hotel !
Collectively, world’s reefs are less than .5% of the earth’s surface, but they are home to over 25% of all ocean species. The Great Barrier Reef is home to 1,600 species of fish and 600 species of coral.
We found ourselves surrounded by thousands of little fish a few times.
The Great Barrier Reef is both surprisingly old and surprisingly new. Its roots date back 500,000 years, but its form has changed with the sea levels over the millennia. The current reefs took their shape only about 7,000 years ago, after about 13,000 years of slowly rising sea levels as the last ice age ended. Much of the current reef is on the tops of what used to be very old mountains!
We loved these feather stars. They are cousins to sea stars.
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CORAL
The Great Barrier Reef can be thought of as giant underwater coral forest. We learned so much about these beautiful and mysterious animals and the houses they build.
At first glance, coral may look like a colorful rock… But coral is not a rock – coral is alive! What people normally call coral is actually a group of thousands of little animals called polyps and the protective limestone housing they build for themselves. Polyps are cousins of jellyfish, and the have a sac-like body with a mouth surrounded by stinging tentacles. Most are less than half an inch across and they don’t have hearts — or even brains!
When the polyps die, their skeleton housing stays behind. New housings are built on top of old ones again and again. Over centuries, huge coral reefs are formed. These reefs provide shelter for other sea plants and animals, creating a super diverse ecosystem.
The Great Barrier Reef (and all reefs) started as just one coral polyp. It is fun to think of these teeny creatures without brains building something this complex and huge!
Some more fun things about coral polyps -
All the coral polyps in a colony are clones! (Meaning they are genetically identical.)
They are nocturnal. They stay inside their housing during the day. At night, they extend their tentacles to feed.
Coral polyps are clear like jellyfish- their amazing colors come from millions of tiny algae that live inside the coral polyps! The algae and coral polyp have a symbiotic relationship. The algae gives the polyp food, and the polyp gives the algae a safe place to live.
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SOFT CORAL
Soft corals look like plants but they are animals, too (just like hard coral). What looks to us like 1 plant is actually a colony of thousands of teeny polyps that live together in a larger structure.
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ABORIGINAL CAVE
We got off our boat one day to hike to an old Aboriginal cave on an island in the reef. Amazingly, the Ngaro people lived in this area for so long that they were here when it was land!
Over most of their 30,000 years in the area, the Ngaro hunted and found food in the valley between the local mountains. As the last major ice age slowly ended, global sea levels rose about a third of an inch a year for 13,000 years from about 19,000 BC to about 6,000 BC. This 400 foot increase in sea levels meant that the local mountain tops became islands in the sea, and the fertile valley became the harbor where our boat was. Fossil evidence shows that the Ngaro people adapted by focusing on fishing, building boats, etc.
Westerners only found the Great Barrier Reef about 250 years ago. Captain James Cook discovered the reef the hard way – by running his ship into it!
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FUN IN THE WATER
Hazel turned out to be part fish!
We also found these cool sea scooters. Jamie had wanted to ride on these ever since he saw the James Bond movie Thunderball when he was about 9. They were a blast!
Hazel was a natural.
Tired after a long day at the reef…
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MEANWHILE, BACK ON LAND…
We managed to get a real American Thanksgiving meal, which is very hard in most other countries. Definitely a lot to be THANKFUL for this year!
One crazy surprise at the hotel: thousands of huge bats that come out around sunset! Australians call them Flying Foxes.
Fun things about these bats
Bats are the only flying mammals
They give birth upside down!
These bats are vegetarians. They eat fruit and leaves — no blood for them! (Although vampire bats are real, and they really do drink blood!! They live in Central and South America, so we wont see them on this trip.)
It is amazing to think that this tropical spot is just a short flight from Sydney.
We also met some new friends at breakfast…
