Marine Biology

A look at the most Dangerous Ocean Reef Predators

Lynn Schwalbe-Larson's image for:
"A look at the most Dangerous Ocean Reef Predators"
Image by: 

A Look at the Most Dangerous Ocean Reef Predators

Ocean/Coral reefs are one of the most intricate and diverse of the world's ecosystems. In regard to the variety of life, coral reefs have been called the rainforests of the ocean. Consisting of the limestone remains of dead coral polyps, reefs span many miles near coastlines such as Hawaii, Florida, Africa and the Great Barrier Reef of Australia.

Coral reefs are home to an amazing array of sea life. Besides the many colorful and fanciful varieties of living coral, you will find jellyfish, shellfish, starfish, sea anemones, crustaceans (shrimp, crabs and lobsters), and scores of fish.

The fish of the reef can be any where between five inches and six feet in length. One of the better-known occupants is the clown fish who live within sea anemones; they clean the anemones for food and the anemone protects them. Quite a few of the fish are docile like the Clown. The less docile ones include the Spotted Grouper, Angelfish and Butterfly fish. These prey upon other fish for food.

With this abundance, it is no surprise that coral reefs are host to numerous other predators as well. Some of the better-known hunters are sharks; specifically the lemon, nurse, white-tipped and zebra. Moray eels hide in narrow crevices, darting out to snatch food swimming by. Barracudas prowl the reefs, and the Manta and Sting Ray feed upon crabs, shrimp, and fish.

Two of the most dangerous and destructive predators of the reef are the Crown of Thorns starfish and the Drupella snail. Both of these creatures feed on the coral itself, having specialized mouthparts that can penetrate the coral's outer protection and feed on the animal within. The Crown of Thorns starfish has been known to wipe out an entire reef, leaving nothing behind but empty limestone. They are also a toxic hazard to any diver who is pierced by one of their spines.

The Drupella snail is the smallest of the predators; full grown it is less than an inch long. But like the Crown of Thorns, it too can wreck havoc on an otherwise healthy coral reef. A sign of the presence of the snail are small white scars on the living coral.

Unfortunately, the largest and even more destructive/dangerous predator than the starfish or snail is our species, human beings. Some prey on the reef directly, others damage the reef indirectly, such as with pollution and over fishing. Dynamite and cyanide are used on coral reefs to collect fish to earn income. Of course the dynamite doesn't discern what it destroys, and large masses of coral reef are wiped out. Strangely, cyanide is used to only stun the fish, which are then collected to be used in aquariums. These fish have a low survival rate; approximately only 10% of them live. The cyanide also kills the coral and necessary microorganisms for the health of the reef. The divers using the cyanide have crowbars to rip apart the reef in order to reach the fish. This is utterly destructive, and those sections of the reef die.

Coral reefs are rich in life and beauty and affect the well being of our planet. They deserve our attention and protection. Predators are a necessary part of the health of a reef, it is only when the Crown of Thorns or Drupella snail populations dramatically increase that there is any threat. The biggest problem is our species. We need to become more widely aware of the consequences of our actions. The biggest solution also lies with us, supporting organizations that gather for the sole purpose of educating the populace, studying the reefs, and protecting them.

More about this author: Lynn Schwalbe-Larson

From Around the Web