Osd ocean sampling day is a day when lots of people In the world will do a big thing for scientists. These are the things that help scientists understand more about the oceans. So we made a secchi disc and went out in the dingy to do our measurements but the secchi disc didn’t sink down so we put on a new weight and then it sank fine. We up loaded our results by using a special app and now they are on a blog where everyone can see them.
We are making so much pollution with cars and buses that oceans are being damaged and fish stocks are dying out.
Some of the changes include:
Altered life styles
Rising sea levels
Over fishing Over fishing is one of the greatest threats to fish. 80% of fisheries are either fully or over exploited If people continue to fish this much then whole fish stocks will die out.
Pollution In the last 100 years there has been a great increase of human population. So the amount of pollution has gone up as well. Farming and industry often put chemicals in the sea. There is an sea of plastic in the Pacific ocean that might be a thousand miles across.
Beach deaths Some times there loads of dead fish on some beaches like there were loads of snapper on a beach in New Zealand. People don’t know weather the fish deaths are natural or man made. Mass whale strandings may be caused by sonar, but scientists are not sure.
All the water in the world is fresh water except for sea water. Fresh water has little or no salt in it. Fresh water is really important for the life of earth.
Where is most fresh water. The most fresh water in the world is at the two poles. The biggest lake in the world is the Caspian Sea. The longest river in the world is the world is the Nile, which in length is 6,650 km.
Fresh water fish. They are different from sea fish. Euryhaline is the type of fish that lives in fresh water and salt water, like Eels and Salmon.
People living on fresh water. The Uru people live on reed islands on a lake in Peru. They make everything they have out of reeds. If there is a war brewing then they make their island float away from the war.
Evolution started with fungi and lichen but the first creatures evolved in the sea.
Scientists now know from studying fossils that they evolved over millions and millions of years to walk on land and breathe air.
Human and land animals evolved from fish. The fish had fins and the fins evolved into feet and legs, and the gills evolved into the lungs, and this allowed them to live on land. So they were called tetropods which means they have four legs.
The earliest type of ocean fish didn’t have jaws and didn’t survive very well, so they adapted to have jaws. The first fish to have jaws was a shark, soon almost all living fish had jaws the ones that didn’t evolve to have jaws became extinct.
Then all the fish swam up to the rivers and became the ancestors of our modern day fish (including the ocean fish).
Some fish continue to evolve like the salmon which changed their spawning time because of global warming.
Evolution is continuing even now and will continue for ever more.
Free diving Free diving is about not having tanks or air. The world record deepest free dive is 281m with fins. The longest time under water was over 11 min.
Submarines Submarines are basically are big tanks of air. They can go deeper than any divers. Periscopes let them see above the surface.
Tunnels under the sea The longest under water section is the Channel Tunnel connecting France and England. Some of the Cornish mines go right under the sea. Some people think there will be cities under the sea in the future.
Self contained under water breathing apparatus Scuba diving is a type of diving unlike free diving scuba diving you carry on your back a tank of air. Divers that go to deep could get the bends. If you get the bends you have to go in a special machine that takes away the bends, called a decompression chamber.
Where Under water volcanos happen where two plates meet under the sea. For example the ring of fire and Iceland.
What They are volcanos under the water.
Chimneys and life around Chimneys are under water volcanos they create spires of rock. They are some times called “black smokers”. Bacteria feeds on the chemicals coming out of the chimney. And the bacteria supports other life forms like shrimps. It can create ecosystems in the deep sea that would normally require sun light.
Why doesn’t the sea evaporate? Some of the sea does evaporate but is always replaced by rivers and rain so the ocean soaks up the heat.
Atolls Is the brim of a volcano and then coral grows on the brim. An atoll only happens in the tropics because coral only grows in the warm seas.
Conditions In shallow water it isn’t very compressed, but in deep water it is so compressed it is like having ten elephants on your back. The deeper you go the darker it gets, because the water above absorbs the light of the sun. Also the deeper you go the colder it gets until you get to a certain depth where it stays the same cold temperature.
How to get there To get there you might think is impossible but we have learned how to do it. The machine that is helping us to do it is called a submarine. A submarine is a big tank of air that protects humans from the water but if you want to go really deep you use a very strong submarine called a bathysphere.
James Cameron is a film director who recently went to the bottom of the Mariana Trench in a mini sub.
Animals Some animals in the deep sea are very strange, for example the Anglerfish has a light on its head to attract prey. There are more than just the Anglerfish, like the gulper eel and the Dragonfish . All these strange creatures have evolved to the deep sea so well they couldn’t survive in shallow water.