I am writing about interdependence in the coral reef. The intermediate dictionary by Scott Foresman says that interdependence means depending upon each other. Here is an example in the coral reef. If you are a herbivore, like the green sea turtle you need green sea plants to live because you only eat plants. Plants that makes their own food by the sun's light. See the green sea plants need the sun to live. The carnivores like the hawksbill sea turtle are the meat eaters so they need fish and anything with meat to live or they'll starve to death. There are also the scavengers; like the yellow-bellied sea snake they pick up after the carnivores. They eat the leftovers, which the carnivore never ate. This shows you interdependence cause the herbivore needs the green sea plant, the green sea plant needs the sun, the carnivore eats the herbivore, and the scavenger picks up after the carnivore. So they all need each other to live. Also, there are the omnivores and we humans are omnivores. That means we are both, herbivores and carnivores.
Interdependence is not just under the sea though. It's all over the world too. Like America trades goods with other countries. The other countries might need goods from us and we might need goods from them because of our climate differences. So then we need other countries to survive too.
My animals, the green sea turtle (herbivore), hawksbills sea turtle (carnivore), and yellow bellied sea snake (scavenger) depend on each other. The herbivores eat only plants like vegetarians, the carnivores eat meat, and scavengers eat dead animals and pick after carnivores.
Green sea turtles are only found in warm tropical waters. Since they are herbivores they eat sea grasses and turtle grass. When they are hatchlings they are carnivores. The female lays egg every two or four year. They lay the eggs where they were born and lay up to one hundred and ten eggs. Female green sea turtles only lay their eggs at night. Eggs must be on land because it has to be warm for seventy days. The mothers don't stay around and see the eggs hatch. So family is not a very big part of the turtle's life. They can swim twelve to twenty-five miles a day. There are low populations of green sea turtle because man keeps catching them at a rate they can't grow back. Nothing has happened yet. But if this goes on I assume that the green sea turtle is going to be extinct.
The yellow-bellied sea snake is a scavenger but it is also a carnivore and hunts. This is because they will get a free meal whenever they can. They aren't aggressive but have the most toxic venom of any sea snake. There is no known anti venom for their bites. The yellow-bellied sea snake rarely tries to bite even if touched. Most of the sea snakes are three to four feet long. Their bodies are flattened sideways and live in the tropical waters in the Indian and Pacific Oceans. They are rarely seen past one hundred fifty feet. The tails are like oars and their fangs are 2.5 to 4.5 mm. They can penetrate the skin easily. The mouths are wide enough to bite a tabletop and are to swallow a fish that is twice the diameter of their own neck.
The hawksbill sea turtle is small and carnivorous. Its adult length is one meter and it is one hundred pounds. The juvenile color is brown, amber and gold, and the adult's color is black dark brown, and richly clouded. It is called the hawksbill because it has a hooked beak-like upper jaw. They use the bills to tear up their prey. The hawksbill has two pairs of shields on the top of its head. They eat fish, mollusks, crustaceans, and also plants. They are also found in warm seas in the southwestern part of the Pacific. The female hawksbill lays up to two hundred eggs every two weeks. The hawksbill is the most valuable sea turtle. It is because of their beautiful shells.
The green sea turtles, hawksbill sea turtle, and the yellow-bellied sea snake are all important to the coral reef. The green sea turtle keeps the green sea plant like seaweed's population down. The carnivores, which are the hawksbill sea turtle, keep the herbivore and fish populations low so they won't eat all the green sea plants. We, humans, also need to eat green sea plants like seaweed. The scavenger that is the yellow-bellied sea snake keeps the ocean clean. If there wasn't any scavenger, the ocean would be polluted with leftover meat.
For another example, assume there are only three animals living at the sea. The animals are the green sea turtle, hawksbill sea turtle, and the yellow-bellied sea snake. If people wanted to make money by catching all the hawksbill sea turtle and they all disappear. The green sea turtles population would grow very high and they eat all the sea plants. But then the sea plants can't grow back quickly so the herbivores will starve. When they die the yellow-bellied sea snake will have tons of food. But soon they will run out. When other yellow-bellied sea snake dies they will feed on it. But that won't last forever.
If humans don't interfere, soon the plants will grow back which will attract herbivores. The tons of herbivores will attract carnivores. When they are done eating and tons of leftover is going to attract the scavengers. So without man things would go back to normal.
Resources:
Arnold, Caroline. "Snake," World Book, 1991.
Bender, Lionel, Life On A Coral Reef, Gloucester Press, New York, London, Toronto, Sydney, 1989.
Caribbean Conservation Corporation, Worldwide Nesting Distribution of the Green Sea Turtle, http://cccturtle.org/green.htm, 1995.
Collard, Sneed B. III, Sea Snake, Bell Book, Honesdale, 1993
Diving Medicine, Sea Snake, http://www.gulftel.com/~scubadoc/seasnks.htm, 12/27/98
Gerhardt, Mike, Hawksbill Sea Turtle, http://www.aea16.k12.ia.us/GR_Schools/bcsd/hmms/Sixth/Species/Turtle.html, 11/24/00.
Hawksbill Sea Turtle, http://www.hpa.edu/TurtleTagging/HawksbillTurtle.html, 11/22/00.
By Traci Mo 