The Great Barrier Reef: Jewels of the Sea

One of the seven wonders of the natural world, this majestic habitation is not one reef, but actually more than 2,800 coral reefs. Nearly 900 islands stretch across 1,600 miles in this area. Thousands of species thrive here in coastal waters of tropical seas, boasting a diversity of animals that rival the tropical rain forests. It is the largest single structure made by living organisms, which is visible from the Earth’s orbit. Unfortunately the reef is being threatened by climate changes, man, over fishing, coral bleaching (due to the expulsion of symbiotic algae or loss of pigmentation), outbreaks of crown-of-thorns sea stars, and things like cyanide poisoning. In order to catch exotic species, divers squirt the poison onto the reef in hopes of stunning fish. Usually the reef will end up dying, as well as the fish.

The Great Barrier Reef contains more than 400 types of coral, 1,500 different types of fish, and 4,000 types of mollusk, 20 types of reptiles, and clams that are over 120 years old. It is home to the dugong, and large green turtle, both on the brink of extinction. Due to the extent of survival of the reef’s species, a protection plan has been enacted to try to help sustain the biodiversity of the species. These are only a few of these wonders.

Clownfish and their anemone

Living in a symbiotic relationship are the clownfish and its anemone. The stinging cells of the anemone offer the clownfish protection from would-be predators. They can also lay their eggs here, and in return, the anemone gets a fish willing to act as a guard. The clownfish cleans parasites from the anemone, and wards of fish that prey on the anemone. When night comes, the anemone gathers itself into a bunch, and the clownfish nestles itself in for the night, protected by a mucus on their skin.

Crown-of-thorn sea stars

They are armed with poisonous spikes, and are ravenous predators of coral reefs. Adult crown-of-thorn sea stars can kill an entire reef. They will project their stomachs out of their mouth and slowly eat away at a reef.

Flatworms

They’re hermaphroditic, and if two out in the open should happen to meet, they’ll mate. Some flatworms engage in penis fencing, where the two will fight. They’ll try to pierce the skin of the other, and the first to succeed will inseminate the other.

Titan triggerfish

They can grow to be nearly 3 feet in length. Titans are the largest of triggerfish. They like to dig for crabs, worms, and other tasty morsels. When they attack sea urchins, they flip them over exposing their softer underside. This way of hunting allows for smaller fish to feed off the scraps. The female triggerfish is such a good mother, that she will continually blow water on them to ensure that they receive oxygen. She will also fiercely guard her eggs. They will also ferociously bite anyone who gets too close.

Cuttlefish

Despite their name, they are not fish, but mollusks. They’re highly intelligent, and are known as the chameleons of the sea, which helps it to sneak up on its prey. They can also use their color-changing abilities for sexual deception. Smaller males will disguise themselves as females in order to evade males larger than them. They will then mate discreetly with the females.

Dugong

They are a protected species in Australia, as less than 2,000 exist here. The Aborigines once traditionally hunted them, and they are now becoming victims of farm soil run-off and fishing nets, as well as dredging of the sea floors. Females only give birth every 3-7 years, which is why the protection of these mammals is vital.

Large green sea turtle

They are green due to the fat deposits under their shell. The largest ever recorded weighed in at over 850 pounds, though their average weight is about 400 pounds.

They are becoming extinct due to hunting, egg collecting, pollution, and nets.

Giant clams

They are the largest bivalve mollusk, and can weigh as much as 400 pounds. Its mantle tissues act as a habitat for the algae of which it gets its nutrition. They are an endangered species due to over harvesting for food and for the aquarium trade.