Sharks have been around for more then 400 million years, the have outlived earthquakes, meteors and a couple of ice ages. By being a APEX predator (No natural predators except sickness) they rule the seas and keeping it all under control. One way of identifying a shark is by looking at their special gill slits, or by counting the amount of fins and their placement.
A reason that not so many fossils are found of the old rulers of the oceans, are because their skeletons are made of cartilage (same as our noses) and not bone. And as most of us have seen, the nose isn’t always found when finding old skeletons.
The sharks has a couple of senses which make sure they are the supreme predator in the ocean;
*Vision (at twilight it even beats the cat), *taste, *pressure, *electrosense (feeling the faint current from a hearthbeat ), *Hearing, *touch and their amazing *scent which with certain substances is over 100.000 times better than humans
They reproduce by giving birth to live pups or by laying eggs. They grow slowly and mature late, some taking up to 18 years before being able to reproduce. Many also only have 2-12 young per brood. This means that with the current shark finning that happens around us, sharks are unable to keep their populations healthy.
Sharks play a very important role in the oceans in a way that an average fish does not. They are at the top of the food chain in virtually every part of every ocean. In that role, they keep populations of other fish healthy and in proper proportion for their ecosystem.
Sharks keep food webs in balance
Sharks have evolved in a tight inter-dependency with their ecosystem. Sharks look after many populations of marine life to the right size so that those prey species don’t cause harm to the ecosystem by becoming too populous.
They are considered by scientists to be a “keystone” species, meaning that removing them causes the whole structure to collapse.
For this reason, the prospect of a food chain minus its apex predators may mean the end of the line for many more species. A number of scientific studies demonstrate that depletion of sharks results in the loss of commercially important fish and shellfish species down the food chain, including key fisheries such as tuna, that maintain the health of coral reefs.
Sharks keep prey populations healthy
Predatory sharks prey on the sick and the weak members of their prey populations, and some also scavenge the sea floor to feed on dead carcasses. By removing the sick and the weak, they prevent the spread of disease and prevent outbreaks that could be devastating.
Preying on the weakest individuals also strengthens the gene pools of the prey species. Since the largest, strongest, and healthiest fish generally reproduce in greater numbers, the outcome is larger numbers of healthier fish.
An important lesson: we need sharks!
Where sharks are eliminated, the marine ecosystem loses its balance.In the parts of the ocean where sharks have been fished out of existence, we can see the dangerous result of removing the top predator from an ecosystem.
The lesson is important. Sharks are being killed for their fins for shark fin soup, a food that has assumed cultural value but is not important for human survival or health. However, removing the sharks can result in the loss of important foods that we do depend upon for survival.
Sharks have survived for 450 million years, but may be gone within the next decades. Life within the oceans, covering 2/3rds of our planet, has enjoyed a relationship with sharks for about 450 million years. Our growing demand for shark fin soup has increased the slaughter of sharks to such a great extent that many shark species are already nearing extinction. Its estimated that we kill around 80-90 Million sharks every year, just for their fins!!
What will the health of oceans be like when such an important group of animals have been destroyed? Do we want the destruction of sharks and the oceans to be the legacy we leave for our children?
Source: Sharksavers
Conny Jeppson
Kon Tiki-Krabi
The epaulette shark (Hemiscyllium ocellatum) is a species of long tailed carpet shark, found in the shallow, tropical waters of Australia and New Guinea (and possibly elsewhere).
Kon-Tiki Thailand 