Overfishing
The oceans were once thought to be filled with limitless stocks of fish, whales and seals. But this is far from the truth. Today fish factory ships and fleets of catcher boats are used to catch as many fish as they can in the shortest possible time.
When driftnets are left abandoned in the ocean they can cause marine life to become tangled. This dolphin probably died of starvation after being caught in a floating ghost net.
Marine Dumps
Humans have always treated the ocean as a big garbage dumpster. Some of the items thrown away can injure and even kill marine animals. Marine mammals can become tangeld in discarded fishing nets and drown. Plastic bags can be mistaken for jelly fish and be eaten by seals. Plastic six pack rings can find there way around animals mouths causing the animal to die of starvation.
Oil Spill
Oil spills happen when ships carrying oil spring a leak or run aground. One of the worst spills ever occured off the Alaska coast in 1989 when the oil tanker Exxon Valdez and dumped more than 40 million litres of oil into the ocean. So what happens? The oil coats animals, such as sea otters, and many sea birds and often kills them. Animals accidently swallow the oil which then poisons them. Some of the oil sinks to the bottom and gets into the food supply. Some of the oil washed up onto the beaches and covers them with a thick oily sludge.
Here are some experiements that will allow you to see the effects of oil in this environment:
How does oil effect birds?
Materials: 2 small bowls, tap water, cooking oil, 2 feathers
Fill the bowls with water, add 3 table sppons of oil to one of the bowls of water.
Place one feather into the bowl of water examine the feather.
Is it wet or dry? Why?
Place the other feather into the bowl of oil and water.
Is it wet or dry? Why?
How do you think oil spilled from tankers or leaking oil could affect birds and other wildlife?
Try cleaning up your own oil spill
Materials: shallow pan, water, a mixture of vegtable oil and molasses, pices of paper, q-tips, cut straws, string, sponges
Place water into pan, slowly add oil mixture, slowly blow on the oil What is happening?
Using your materials try to clean up the spill as quickly and effectivly as possible. Remeber you must try to leave as much water as possible. What worked well? What did work? What did you learn from this experiment?
What to test your ocean pollution awareness try this
pollution
quiz from ocean
link.islan.net
 |
 |
 |
 |