The 70% of our World covered in water, holding 80% of all life on earth is still a mystery to many of us. A World so completely different than that we live in on the surface, the underwater world has often been described as an alien planet right here on Earth. So much so, that Writer- Director of the superhit movie ‘Avatar’, James Cameron created the Alien Planet of Pandora with influences and some striking resemblances to marine life and underwater landscapes (Read:James Cameron’s Love for Scuba Diving Shows in Avatar).
Here’s a look at some Frequently Asked Questions about this Wonderfully Wacky World Underwater (including some you may never have thought of before) -
How Do Marine Animals Navigate the Underwater World?
You’ve probably heard of marine animals like whales or turtles migrating thousands-of-miles across open oceans, through ferocious storms and past the shores of many different countries only to return again to the same spot at a later time in the year or in the next.
It isn’t as simple as getting onto the ‘Interstate 95 and going straight till you hit an exit at 75′. So how do they do it with no roads, landmarks or gps?
From what we’ve learned, many marine animals use a combination of their senses, including sight and sound which is sometimes known as ‘echoloacation‘. How this works, is they project sounds called sonar clicks, that are reflected back when the sounds strike an object which allows these animals to determine the distance of objects (food, predators) as well as features of the underwater environment (shorelines, seafloor depth, topography) for navigation purposes. While this explains only part of how they can navigate underwater and don’t bump into things, for their migratory travel marine animals use what God gave them- a ‘sixth sense’ which acts like a built in compass and allows them to detect and ride the magnetic energy of the Earth.
Turtles,whales, sharks, tuna, salmon, trout, spiny lobsters, sea slugs, birds, in effect, have the equivalent of a GPS system that’s based on magnetism. They respond to specific magnetic fields that exist in different parts of the ocean and use the inclination angle and intensity of the Earth’s magnetic field as guidelines to determine the direction they want to go in. In short marine animals use their biological compass to make global migrations along magnetic highways in the Ocean’s. How they have developed this skill and how it seems to work the way it does, remains one of the big unanswered mysteries of the marine world.
Do fish ever get thirsty?
If fish ever reach the point they get thirsty, I think not. However, Fish living do need to drink a lot to avoid shriveling up like prunes. Water flows in and out of a fish’s body through a process called osmosis .In osmosis, water moves from where there is less dissolved salt to where there is more. Since seawater is saltier than the liquids in a fish’s body, water inside the fish is constantly flowing out and the fish drinks to replace the lost water.
Which Marine Animal is the Top Predator of the Seas?
If you just thought “Oh, that’s easy, it’s the Great White Shark”, you’re wrong! Killer Whales are the only sea animal that outranks the Tiger Shark and Great White Shark as top predator of the seas. 
Regarded as apex predators, killer whales have no natural predators and prey on some of the other fierce predators of the ocean including sharks and other whales like minke whales, gray whales, sperm whales and blue whales. They have also reported to be drawn to cannibalism, though it’s not common as they hunt and live in groups called pods. With a wide diet ranging from cold-blooded fish to seals, sea-lions, penguins ad so on, however, it’s most startling hunting is not in the ocean but on the beach when they swoop up with a swell onto the beach seizing unsuspecting seals and sea lions.
Can Fish Swim Backwards?
A number can, but usually don’t. Those that can are mostly members of one of the eel families.
FUN FACT: “Floating gold” is another name for Whale vomit, or ambergris, which can fetch between $10 and $20 per gram. Ambergris is used as an ingredient in fine perfume because of its unique odor and ability to make a scent “stick” to the skin.
More Questions:
Do Fish Fart?
How long do fish live? How can you tell the age of a fish?
Do Fish sleep?
What is the World’s Largest Fish? The Smallest?
*Photo Credits: photos by aSIMULAtor, mrmritter on flickr
