Half of Great Barrier Reef Gone

Gabe Kline
http://news.discovery.com/earth/great-barrier-reef-half-gone-big-pics-121002.html

Summary: The Great Barrier Reef in Australia is the largest reef in the world. It is 133,000 square miles large. Recent surveys have shown that in the past 27 years the reef's size has decreased in half. Katharina Fabricius has been spending almost 25 years surveying various parts of the reef. She has surveyed 214 reefs and 2,258 surveys to determine the rate of decline. They did fine local differences as the northern end of the reef is still picturesque. The biggest factors that have caused the reef to decline is the Crown of Thorns starfish, the climate change and tropical cyclones. The Crown of Thorn Starfish is an invasive species, who eats the coral. The starfish is boosted by agricultural runoff much like algae. These can grow up to 3 feet in length and can have as many as 21 arms and are covered in poisonous spines. They are responsible for 84% of the decline in the reef. The younglings eat the coral and leave the skeletons behind, creating a barren wasteland. The climate change, causes the coral to bleach. The coral polyps at high temperatures secrete the algae inside them. This causes the coral to bleach. Nothing can be done about the category 5 storms which batter the reef every year. In the short term, finding ways to keep the starfish population low, as they usually are, could bring back the reef to normal conditions in 20-30 years.

Connection: The Coral Reef is the most diverse marine ecosystem. It is much like a rain forest, in that a large chunk of species live on them around the world. Also just like rain forests, coral reefs are threatened by climate change and human interaction. Also it has to do with invasive species, because the Crown of Thorns in wiping out native populations.