Hawaii Nature Focus
Albatross Project
Wild Things
Lecture Series
Games
Booklet # 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17 / 18
 

 

 
No. 15
  

 

TIDEPOOLS: WHERE THE OCEAN MEETS THE ROCKY SHORE
Tidepools exist where the ocean meets the rocky shore. The movement of the tide creates an area that is sometimes covered with water and sometimes dry. These areas are called tidepools because pools of water are left when the tide goes out. A number of plants and animals live in this always changing area. They are adapted to life with the tide. The plants and animals that live in the tide-pools are very unique. They can live in an environment that changes greatly each time the tide goes in and out. These plants and animals must be able to survive changes in temperature, oxygen, and salinity. They must also be able to survive life on a rocky shore with a pounding surf.
 
TIDES
Why does the tide go in and out? The tide is mainly the result of the moon. The moon and the earth spin around each other. The water on the side of the earth closest to the moon rises
toward the moon because of gravity. The water on the opposite side of the earth from the moon also rises up. This is because of centrifugal force. If you fill a bucket with water and spin it quickly around, the water does not fall out; centrifugal force is
pushing the water to the out-side. The water rises on the side of the earth closest to the moon and the side furthest from the moon. This is called high tide. The other parts of the earth have low tide. As the moon travels around the earth, the high tide travels around the earth. There are two high tides and two low tides each day. When the tide is coming up, it is called a rising tide. When the tide is going back out, it is called an ebbing tide. In Hawaiian, the tide is called kai, the same word for sea, sea water, and the area near the sea. Kai make means dead tide - the water is flat and still. Kai malo'o means dry tide or low tide - the coral reef is exposed. Kai ui means big tide or high tide. Kai pi'i is a rising tide and kai ho'i is an ebbing tide or a returning tide. If you look up kai in a Hawaiian dictionary, you can find many different ways to describe the tides and the sea.
 
LIMU
The plants in tidepools are called limu. They are algae, mainly seaweeds, and they come in many different colors, shapes, and sizes. There are people who collect limu by walking along the tidepools, or on the coral reef, at low tide. The collected limu is washed in fresh water and pounded. A little salt is added and the limu is eaten with other foods, such as fish. Limu is very nutritious. Three of the favorite kinds of limu are limu kohu, limu 'ele'ele, and limu lipoa.

 

OPIHI
Opihi is a shellfish that lives on rocks at the shoreline. The three kinds of opihi that live on the main Hawaiian islands are endemic to Hawaii, which means that they only live in Hawaii. The two most com-mon species are called opihi makaiauli (black foot opihi) and opihi alinalina (yellow foot opihi). The black foot lives higher on the shoreline than the yellow foot. A third species, opihi ko'ele, lives in deep.ocean waters. Opihi cling to the rocks with a strong foot shaped like a suction cup. Their single shell is shaped like a cone. Because of their foot and their shape, the strong waves cannot push them off the rocks. When the tide rises and covers the rocks, opihi use their muscular foot to move around. With a tiny mouth, opihi scrape algae
off the rocks. Opihi often return to the same spot, a home spot, to rest each time the tide goes out. Opihi are gathered for food by many people. Once the opihi is touched, it clings even tighter to the rock. A knife is used to pry the opihi from the rock. Opihi gather-ers must work quickly, while constantly watching the ocean. The meat of the opihi is eaten raw out of the shell. They are very tasty and nutritious. The shells of opihi are used for scrapers, peelers, and other tools. The shells are also used to make jewelry.

 

PIPIPI & KUPE'E
Pipipi look like snails. They are small and black. Pipipi clamp tightly to the rock at low tide, waiting for the tide to rise. At high tide, they scrape algae from the rocks with their sharp

tongue or radula. To eat pip-ipi, they are boiled in water and salt and then pulled out of the shell with a pin. Kupe'e are a larger relative of pipipi. They are collected at night during low tides. They are eaten and the shells are used for neck, wrist, and ankle ornaments, often for hula because of their rattling noise.

 

HA'UKE'UKE
Ha'uke'uke is a type of sea urchin often seen on the rocky shore. All sea urchins have an exoskele-ton, a skeleton on the outside of their body. This skeleton is round and often has many spines stick-ing out (wana is the long-spined urchin and ina is the short-spined urchin). Ha'uke'uke has short stub-by spines around the top if its body and longer spines around the bottom that help to hold onto the rock, along with tube feet. When the pounding surf hits the rock, the ha'uke'uke won't be swept to sea. The mouth of the urchin is at



the bottom of the body. Most urchins eat algae with five teeth in their mouth. People gather and eat ha'uke'uke much like opihi.

 

A'AMA
A'ama is a black, rock crab. There are many crabs off the shores of Hawaii. All crabs are called papa'i in Hawaiian. On the rocky shore, the a'ama wanders. A'ama are active dur-ing the day, feeding at the water's edge and quickly running into the water if frightened. A'ama are caught by fisherman, sometimes by using opihi as bait.

 

 

TIDEPOOL PROTECTION
Why should you care about the plants and animals in tidepools? All the living things in the world, including humans, are in some way connected. Scientists still do not understand all of the connec-tions, but it can be compared to a spider's web. If one spot is touched, the entire web will move. To protect the plants and animals of the tidepools, several things can be done:

  1. Follow the rules. Fishing rules exist to protect the species, usually by allowing animals the chance to grow and have young before they are caught and eaten.

2. Don't pollute. Polluted waters kill the plants and animals of the ocean.

3. Support protection. Laws that protect areas of the ocean help the plants and animals. There need to be areas set aside just for wildlife.

4. Learn! The more you know about the plants and animals of the ocean, the more you can do to help. You can also share what you know with your friends and your family.