One of the greatest pleasures and privileges in my long life was floating over the Great Barrier Reef in 1994. And seeing more tiny fish than I ever believed possible swimming in and out of corals and sponges. The entire reef system spreads out over 134,600 square miles. To give you an idea of the scale, this is larger than the state of New Mexico, America’s fifth biggest state.
Great Barrier Reef: A Kaleidoscope of Diverse Life
Observers have spotted 30 species of whales, dolphins, and porpoises visiting the Great Barrier Reef paradise. There are more than 1,500 fish species swimming peacefully as they do. Moreover, there are 6 species of turtles that depend on the refuge to breed.
The Great Barrier Reef also houses 400 coral species, and 500 different marine algae or seaweeds. The food web comprises the coral polyps, seaweeds, and algae fish feed on, and the predators that consume them in turn. Finally, decomposing organisms break down dead organic material and return nutrients to the sediment. If any link in the chain breaks, the system could die.
Climate Change: The Greatest Threat to the Reef
Corals are the structural foundation of the entire system. Waves of crown-of-thorns starfish are threatening them, as warmer sea temperatures enhance their larvae development. Moreover, the global temperature’s rising is increasingly causing coral bleaching in the summer. This causes the coral polyps to expel the algae living in their tissues that fish feed on.
Algae in coral polyps are crucial for the future of the Great Barrier Reef because they provide 90% of coral’s energy. Without them, coral begins to die. Some of it never recovers, after the polyps starve. Algae then cover their calcium carbonate skeletons blocking the possibility of regeneration. Eventually, the coral skeletons could erode and the entire reef structure collapse.
Coral reefs represent some of the world’s most spectacular beauty spots, but they are also the foundation of marine life: without them many of the sea’s most exquisite species will not survive. (Sheherazade Goldsmith)
Related
Climate Change Evidence: Ocean Acidification
Climate Change Evidence: Warming Oceans
Preview Image: Healthy Corals