Underwater Ecosystems Hawaii
Hawaii Reefs - From above the ocean looks empty like a desert made of water, it seems Baron and uninhabited but that's just on the surface. Come below the waves with me as we explore the riot of color and life that exists on the coral reefs. Coral reefs are only found in shallow tropical seas, they may look like colorful rocks or even plants but coral is really an animal
What is Coral?
Hawaii Coral - Coral is built by polyps. "What exactly is a polyp?", you might ask. Polyps are very small creatures that are related to jellyfish. However, unlike the jellyfish which propel themselves around through the water, coral is stationary and they grow together in a colony called a coral head. A coral head is a small piece of coral may be made of hundreds of polyps and a bigger one may have thousands! Hard corals create the reef by secreting calcium carbonate or limestone. This is a type of rock which gradually builds up into a solid structure. Coral grows slowly only a few centimeters a year and it can take hundreds of years to form large pieces. Not all coral is hard. Some types are soft and they may look like fans, bushes, or feathers… but once again it is really a colony of tiny animals living together!
An Underwater World
Hawaii Reefs - When many corals grow close together it's called a reef. Reefs provide very important habitat for fish and other sea creatures. Hawaii reef's provide shelter for little fish and a place to hide. This is the perfect protection when it comes to larger ocean predators. As we all know, smaller fish will eventually attract bigger fish. The reef benefits these smaller fish from becoming lunch or dinner whenever bigger predators arrive.Shallow reefs are the perfect praying grounds for larger predators such as sharks. However, some of these sharks not only utilize the Hawaii reef system to hunt for food... Smaller species of sharks have been known to live within the shallow-water reef ecosystem.
It's a Shark!
Underwater Predators - Nurse sharks will hide under ledges or in crevices of the reef and come out at night to eat dormant fish that are hiding in the coral. Nurse sharks are slow-moving bottom dwellers and for the most part harmless to humans, although they can grow up to 14 feet! That is more than four meters in length and they're strong jaws allow them to crush shellfish and even coral if needed. However, us humans don't need to worry too much. Nurse sharks tend to be very timid and rarely provoke ocean goers. There has not been a documented Nurse shark attack in human history. Don't be so frightened! These pleasant sharks prefer to eat shrimp, fish, and squid.
Lovable Sea Creatures
Other Underwater Creatures - The reef also provides a place for algae and sponges to grow. This provides food for a variety of creatures. For example, the green sea turtle, like most other kinds of sea turtles, is endangered due to hunting and getting their shells trapped in commercial fishing nets. Their populations are declining these Turtles rely on the food that grows on the coral reef and the reef in turn relies on the turtles. It's a partnership that benefits both creatures! The turtles get a reliable source of food and the reef system gets a less obvious advantage. Without the Turtles coming to eat the algae and sponges, they would overgrow the reef and prevent the coral from growing and expanding. With lower turtle populations in oceans worldwide, the health of coral reef systems will suffer. It is important for people to do their best to protect these peaceful reptiles, not just for their sake, but for the health of the entire coral ecosystem. Turtles and coral aren't the only partners you can find on the reef...
Small but Painful
Sea anemones - The has another animal that seems more like a plant and are a close relative to both coral polyps and jellyfish. Anemones have their own partner to help make life easier…. Clown fish. Although it may not look like it, anemones are predators that have stinging cells in their tentacles which allows them to paralyze their prey. This is usually small fish or shrimp and after paralyzation, they move them towards their mouth. Clown fish escaped the anemones stinging by covering themselves in a protective layer of mucus. By hiding inside, the Clown fish are protected from predators and they don't want to be hurt by the enemy. Just what does the anemone get out of this? Well, the little clown fish can chase away butterfly fish that would eat the anemone and they can also clean the anemone of parasites and bits of food that the anemone has no way of cleaning itself.
An Unusual Relationship
Ocean Relationships - There's one more unusual pairing. Can you guess what parrot fish and beaches have in common? Parrot fish are a distinctive family of fish species with a tough bony beak. Their beak is so strong that they can bite through rock and coral. They do this so they can eat the coral polyps and algae inside. Due to this, the coral is ground up and all the edible parts are digested until only the limestone remains. Next, the parrot fish has to get rid of all the crushed limestone and there's only one way to do that! The parrot fish will excrete or poop out the limestone, which has been crushed into a fine sand. In this way, a single parent fish can produce 200 pounds or 90 kilos of sand every year. You heard that right! The next time you bury your toes in the soft white sand at the beach, just remember you're making castles with fish poop!
The Ocean Needs OUR Help!
Help Protect our Ocean - Coral reefs are sometimes called the rain-forests of the sea! They cover only a tiny area of the ocean and provide a habitat for a quarter of the ocean animals. Unfortunately, the coral reef ecosystems are fragile and delicate the balance between the coral algae fish and animals that live there. Also, they are easily disrupted. Over-fishing by humans, ocean pollution, and warming temperatures have all put the world's coral reefs at risk. Right now, more than half of the world's reef systems are in danger of destruction and if nothing changes then within 15 years… nearly all the coral in the world will be in danger of dying and disappearing. Fortunately, there are some simple things you can do to help protect coral reefs. Please be careful not to waste water or pour chemicals down your drain, because eventually the water you use will reach the ocean and increase pollution. This can already be seen taking place on Oahu, HI. Also, please make sure to pick up trash that you see on the ground and recycle. Anything you can do to prevent the garbage from finding its way into the water. Most importantly, make sure people know that you want to protect the coral reefs, so when we make decisions about how to take care of our world, we will make choices that will protect the reefs!