Mr. Perry Alexander's 6th-grade class at Waimanalo School recently visited Sea Life Park, and afterwards they sent in lots of good questions, some of which are answered here.
Blake Kalama wants to know, "Why do we have sand on our beach?"
We have sand because over the course of many years waves have ground coral, lava, and shells into small grains of sand. The light-colored beaches in Waimanalo are made of sand that comes from the crumbled skeletons of marine animals such as mollusks, crabs, corals, and the skeletons of marine plants called coralline algae. On other islands you can find black beaches made of sand that comes from black volcanic rock, greenish beaches caused by grains of olivine---a green mineral found in volcanic rock, and reddish beaches caused by red cinder rocks and red clay soil. Next time you're at the beach, look carefully at a handful of sand and see if you can tell what it's made of.
Robert Kamau'u asks, "How many tropical fish are there?"
There are about 680 species of fish in Hawaiian waters. About 420 of these are reef and inshore fishes. Approximately 30% of Hawaiian fish species are only found here (endemic). Because our islands are so isolated, we have fewer species than other areas (the Phillipines has about 2,000), but we have more that are unique to Hawaii; examples are the Milletseed Butterflyfish (lau-wiliwili) and the saddle wrasse (hinalea lau-wili).
Torrie McKeague asks, "Why do eels look like snakes?" and Dexter Lazo wants to know, "Why are moray eels nice looking, but dangerous? "
Eels (puhi) are fish that have adapted to living in the holes and crevices of rocks and corals. They don't have side fins like most fish. so their streamlined shape enables them to swim in and our of pukas easily. They hide their long, narrow bodies and poke their heads out to catch passing fish with their sharp teeth. They are strong, fierce, agressive animals and have few enemies in the coral reef where they live. They may look mean when they open and close their jaws, but that is the way they breathe. The jaw movement pumps water into the mouth and out the gills. They are not apt to bite unless provoked or unless a person is foolish enough to put a hand near their jaws.
Chistina Lui wondered "Do fish have teeth?"
Fish do have teeth and the size or shape of the teeth hold clues as to how that fish eats. Some fish have teeth on their gill arches, the roof of their mouth, and even on their tongues! The teeth of an adult parrot fish fuse together so that it's jaws look like the beak of a parrot. This strong beak can then be used to break off chunks of hard coral. But when one thinks of fish teeth, usually sharks come to mind. Shark teeth may be large or small, sharp or blunt, saw-like or knife-like, but the best feature is that they are replaceable. Shark teeth are arranged in rows so that as teeth break or fall out, the next tooth or row of teeth move forward and function as a brand new set. Scientists estimate that for some shark species a single shark may go through as many as 30,000 teeth during it's lifetime.
Chasadie Sanchez's question was "How can a whale hold it's breath underneath the water for so long?"
Sperm whales are champion divers and dive longer and deeper than any other mammal in the world! There is evidence that they can go as deep as 2 miles and hold their breath for 2 hours or more. Whales are mammals, so they have lungs, not gills like a fish. To survive these deep dives, sperm whales have adapted special abilities. At a depth of about 330 feet, their lungs collapse completely. Unable to store oxygen in their lungs, whales have adapted to store oxygen where it is most needed - in their muscles and blood. They also are able to control the flow of blood to only the essential organs, such as the brain. The beat of their heart can also be controlled. It is slowed down during a dive to 10-50% less than at the surface.
Keep the questions coming!
Send your questions about ocean life to: Sea Smarts, Education Center, Sea Life Park, 41-202 Kalanianaole Hwy. #7, Waimanalo, HI 96795 or FAX 259-7373