There are billions upon billions of creatures in the 7-mile deep oceans. Amongst them live the supremely graceful, beautifully evolved, super-predator and most feared animal on Earth -- Carcharadon carcharias or great white sharks.
In fact, there are 368 species of sharks that inhabit our oceans.
Since the 1850s overfishing has changed life under the sea. Northern cod, North Sea skate, marbled rock cod of Antarctica and bluefin tuna are fished out, like the great whales before them and they are not recovering.
Sharks, rays and seahorses are on the road to extinction. East coast cod has declined 96 percent over the past 150 years.
Sharks in particular have been brutally slaughtered for their fins, which fetch tens of thousands of dollars and then wind up in Asian soup bowls.
Magnetic fishhooks are helping to save sharks, and just in the nick of time.
A series of dark holes peppering the top and underside of the snout resemble a five o'clock shadow. The tiny, jelly-filled capsules, called ampullae of Lorenzini, are sensitive to electrical discharge as minute as .005 microvolts. This enables sharks to detect a heart beat of prey buried in sand from a faint electrical field or the action of a gill or a swimming muscle of another animal. These sensors also assist sharks in navigating using Earth's magnetic field.
A spinning magnet on a fishhook overwhelms those electrical sensors. Much like waving a bright flashlight across human eyes, it's temporarily blinding, startling and most unpleasant.
Several countries are now testing these Smart Hooks and so far test show a 60 to 70 percent reduction in the number of sharks caught.
Kudos to scientist Eric Stroud and his company Shark Defense for helping to protect sharks.
Each of us can make a huge difference with our buying habits. Only buy fish that has the Marine Stewardship Council certification of sustainable fisheries.
As voters and consumers, we can exercise a unanimous voice for the conservation of all wild fish stocks and including sharks, and all life within the ocean.
Earth Dr Reese Halter is an award-winning science communicator, distinguished conservation biologist and author of The Incomparable Honeybee and The Insatiable Bark Beetle.
Follow Dr. Reese Halter on Twitter: www.twitter.com/DrReeseHalter
Carl Safina: They Left Us... Bones
When I was a real little girl, my mother's friend had many aquariums. She also had seahorses, and I fell in love instantly with them. I have loved them for a lifetime and feel sorry for future generations who might never encounter these magical living beings that look like they are from a magical kingdom.
We need to save both sharks and seahorses because it is all one, a living, life giving Earth.