Activities

Octopus

Glue together two cup sections from an egg box. Cover them with black paint.  Attach 8 wool tentacles with glue to the bottom.  Cut eyes and mouth from paper and glue them in place.

Fishy Facts: The Octopus

The word octopus means "eight feet." Octopuses are solitary, eight-armed animals that live on the ocean floor. There are over 100 different species of octopuses and the largest is the Giant Octopus. This huge mollusc is up to 23 ft (7 m) from arm tip to arm tip, weighing up to 400 pounds (182 kg). The smallest is the Californian octopus, which is only 3/8 inch (1 cm) long.

An octopus has a soft body and eight arms. Each arm has two rows of suction cups. If it loses an arm, it will eventually regrow another arm. It has blue blood. An octopus has an eye on each side of its head and has very good eyesight. However, it cannot hear. Octopuses eat small crabs and scallops, plus some snails, fish, turtles, crustaceans (like shrimp), and other octopuses. They catch prey with their arms, and then kill it by biting it with their tough beak, paralyzing the prey with a nerve poison, and softening the flesh. They then suck out the flesh. Octopuses hunt mostly at night. The octopus swims by spewing water from its body, a type of jet propulsion.

Only the Australian Blue-ringed Octopus has a poison strong enough to kill a person. Octopuses live in dens, spaces under rocks, crevices on the sea floor, or holes they dig under large rocks. They pile rocks to block the front of their den. The den protects them from predators (like Moray Eels) and provides a place to lay eggs and care for them (a mother octopus doesn't eat during the entire 1 to 2 months she is caring for her eggs). In order to escape predators, octopuses can squirt black ink into the water, allowing it to escape. Another defence is that they change their skin colour to blend into the background, camouflaging themselves.

Jellyfish

Children can make jellyfish by colouring paper plates and hanging red, yellow, and/or pink crepe paper tentacles from the plates. Hang the jellyfish from the ceiling so they look like they are floating in the water.

Fishy Facts: The Jellyfish

A Jellyfish is an invertebrate made up mostly of water, it has no heart, brain or bones. It is made up of 95-97% water, 3% protein and 1% minerals. They range in size from about 2 1⁄2cm to 61 m long. They have been drifting through the world's oceans for more than 650 million years. They swim by jet propulsion. The jellyfish will expand then quickly contract its bell-shaped body, which forces water away from the bell and pushes the jelly in the opposite direction.

To capture prey for food, jellies have a net of tentacles that contain poisonous, stinging cells, called cniodocytes. Each of these cells contains a nematocyst which acts like a mini-harpoon. When a jellyfish touches something the nematocyst is released and injects toxin into the prey. Australia's box jelly has a lethal toxin more potent than cobra venom and can kill a person in minutes. Another poisonous jellyfish is the Portuguese man-of-war found in Gulf of Mexico; Caribbean Sea near the Bahamas; West Indies. If you are stung, wash the wound with vinegar or surgical spirit. Don't rinse with water, which could release more poison. All jellies sting, but not all jellies have poison that hurts humans. Of the 2,000 species of jellyfish, only about 70 seriously harm or occasionally kill people.

Did you know?

• Jellies being in the Earth's oceans for over 650 million years means they were here before the dinosaurs!
• The largest jellyfish has a bell that can reach 2.4 metres across and tentacles that extend over half the length of a football field. Imagine coming across that while swimming!
• Many people consider jellies a delicacy. They are dried and de-salted to provide a nutrient-rich, low fat, low-calorie meal. It could become the next diet-craze food, you never know!

Sand Bottles

You will need:

• Fizzy drink bottles
• Funnel
• Sand (Soft 'sand box' sand, not building site sand!)
• Water
• Blue food colouring
• Shell pieces
• Wood
• Plastic jewels
• Glue

What to do:

1. Save some soda bottles and the lids. 
2. Using a funnel, fill bottle about 1/3 full of sand. 
3. Add water and a few drops of blue food colouring. 
4. Add broken shells, pieces of wood and maybe even some plastic jewellery treasure. 
5. Glue the lid on the bottle and let the kids shake them up and let them settle.

Fish In A Bottle

You will need:

• A plastic 2 litre bottle with lid
• Blue food colouring
• Two small balloons
• Glue

What to do:

1. Fill a clear plastic 2-litre bottle one-quarter full with water. 
2. Add a few drops of blue food colouring.
3. Blow up two small balloons, release most of the air and tie the ends closed. 
4. Push the balloons into the bottle.
5. Put glue around the rim of the bottle and screw the cap on tightly.
6. Let a child hold the bottle on its side and gently rock it back and forth to make the balloon fish swim.

Salty Water

You will need:

• Wide mouth plastic jar
• warm water
• Salt raw potato
• Measuring cup
• Spoon

Did you know that it is easier to float in the ocean than in the swimming pool. Do you know why? Salt. The Ocean is full of salt. Salt water can hold up more than plain water. That is why you can float in the ocean more easily.

What to do:

1. Pour 1 1⁄2 cups warm water in the jar.
2. Add ¹/₃ cup salt.
3. Stir until all the salt is gone.
4. Add another 1 1⁄2 cups of water.
5. Pour it over the back of a spoon into the jar. Pour SLOWLY so the two liquids do not mix together.
6. Slowly put the potato into the jar. Do NOT drop it. Potato sinks-but stops halfway.

What’s going on?

Salt water is heavier than plain water, so it stays on the bottom. Plain water floats on top of salt water. You cannot see the difference though. The potato is heavier than plain water. But potato is lighter than the salt water. That is why it sank only half way. It is floating on top of the salt water.

Sound of the sea in a seashell

Have you ever put a seashell to your ear and heard the sound of the sea? The same effect can be heard by putting a cup over your ear.  People thought it was the sound of blood rushing though the skull but it is not.  Put the cup over your ear and listen, then move the cup slightly away from your ear and listen again - can you hear the sound change? We are surrounded by sound constantly but we tend not to notice all the background noise.  However, when you put something near your ear it strengthens a certain group of frequencies. The cup or seashell provides a resonating cavity. By changing the shape of the resonating cavity you can change the pitch.  Try this by snapping a finger against your cheek as you form smaller and larger O’s with your lips. Certain wavelengths prefer a wide-open mouth; others prefer a smaller space.

So there we have it.  All this noise flies around all the time. Forcing these sound waves to bounce off something before they enter your ear changes the mix of frequencies that are resonated, or strengthened. So the sound waves suddenly sound different. And sometimes, they sound like waves on a beach.

Shwooooshhhhhhhhhhhhhhhhhhh….

Make a rainbow fish

You will need:

• Coffee filter paper
• Red cabbage
• Water
• Lemon juice or vinegar
• Bicarbonate of soda
• Children’s paintbrush
• Wiggly eye or paper eye
• Silver foil

What to do:

1. Prepare some red cabbage water by breaking red cabbage leaves into small pieces.
2. Pour hot water over the cabbage leaves and leave for half an hour.
3. Decant the purple liquid.
4. Soak the filter papers in the cabbage water and leave to dry.
5. Flatten out coffee filter on a plate.
6. Cut out a fish shape from the coffee filter.
7. Dip the paintbrush in lemon juice or vinegar and paint onto the fish.  See the colour change?
8. Make up some bicarbonate of soda solution by putting a couple of teaspoons of powder into a little water and mixing it up. Dip in the paintbrush and paint the fish.  See the colour change again?
9. Leave the fish to dry.
10. Glue on some small strips and triangles of silver foil.
11. Glue on a wiggly eye and draw on a mouth.

These colour changes are all due to acid-base chemistry! The cabbage water is purple initially. When you add an alkali such as sodium bicarbonate it will turn  blue but adding an acid such as vinegar will turn it red. Red cabbage contains the pigment anthocyanin and the structure of the molecules of anthocyanin changes depending on whether it is in an acid or an alkali solution. This change in structure means that the pigment can actually change colour from bright red in acid to deep blue in alkali.

Red cabbage water is a good simple indicator and can be used to tell you whether something is acidic or alkali but it cannot tell you how acidic or how alkali. For that you need a more sensitive indicator such as universal indicator or methyl orange indicator.

Rainbow CD fish

You will need:

• 2 old CDs
• Paper
• Large Wiggly Eyes
• Glue
• Wool or cotton

What to do:

1. Using whatever colour of paper you prefer, cut out the fish's lips, two top fins, one bottom fin and a tail.
2. Glue the lips and fins to the side of the CD with the writing on it.
3. Set aside one of the top fins.
4. Cut a piece of wool or cotton 3 - 4 feet long. Tie a knot in one end.
5. Run a line of glue from the hole in the centre of the CD up to the top edge of the top fin that is glued onto the CD.
6. Lay the wool or cotton on top of the glue so the knot is in the hole in the CD.
7. Glue the extra top fin on top of the other top fin to cover the wool.
8. Spread glue all over the side of the CD that everything else is glued to.
9. Set the other CD on top of the glue and match up all the edges. Make sure you have the side of the CD with any writing facing down into the glue.
10. Glue the wiggly eyes on your fish.
11. Glue one on each side of his head. If you don't have wiggly eyes, you can also use a small white pom-pom and a black bead. This will give your fishes eyes a more ‘bug-eyed’ look!
12. The last thing you need now is a fin on the side of the fish. You make these by using a 5 x 6 inch piece of paper.
13. Accordian fold the paper.
14. Once it is folded, hold the folds together and slip in through the hole in the centre of the CD.
15. Centre the paper in the hole and unfold the ends a bit to fluff them out. Add a little glue to hole of the CD and the paper.
16. You can now hang up your completed fish!  

A CD is a fairly simple piece of plastic, about 1.2 mm thick. Most of a CD consists of an injection-moulded piece of clear polycarbonate plastic. During manufacturing, this plastic is impressed with microscopic bumps arranged as a single, continuous, extremely long spiral track of data. Once the clear piece of polycarbonate is formed, a thin, reflective aluminum layer is sputtered onto the disc, covering the bumps. Then a thin acrylic layer is sprayed over the aluminum to protect it.  A laser within the CD player detects the bumps and reads the data. The laser beam passes through the polycarbonate layer, reflects off the aluminum layer and hits an opto-electronic device that detects changes in light.

The incredibly small dimensions of the bumps make the spiral track on a CD extremely long. If you could lift the data track off a CD and stretch it out into a straight line, it would be 0.5 microns wide and almost 3.5 miles (5 km) long!

Gummy Necklace

Make edible necklaces from gummy sharks, gummy fish, and gummy octopi by sewing through with a fishing line or cotton and blunt needle.