Discription Slide 1-8
This lecture revolves around the functions sharks have in the marine realm, and what will occur should they be erased from this planet. Picture: Tiger shark.
The oceans cover 2/3 of the entire earth's surface with the sharks as the most abundant predator over 50 kg (100 lbs) in them. Due to this density of sharks, it makes them the most influential animals of them all.
The ocean is full of sharks, dolphins, whales, seals, turtles, bony fishes as others. They all live in a more or less natural balance and so if one of them get decimated or overly abundant the entire balance is jeopardized.
Due to their abundance and size, sharks represent the ultimate controllers. Their numbers guarantee that no other species can overpopulated, or that illnesses can not spread. Picture: Scalloped hammerhead shark.
Some numbers about the size of the oceans.
Every life originates from the ocean, starting with the smallest organism, which evolved into larger ones over time until finally the bony fishes and sharks appeared.
Sharks, bony fishes as well as humans need to absorbing oxygen which is released in their blood stream. Humans pick up oxygen directly from the air where sharks (already mentioned in the 2nd lecture), absorb oxygen from the water flowing through their gills.
At the same time, sharks need to get rid of their C02 (carbondioxid) which will be given back to the water when it flows through the gills.