Are sharks threatening or threatened ?
Humans have always been fascinated by sharks. Poorly understood and feared, these fish are predators, of course, but most of them are hardly dangerous. Persecuted for no reason, many species of sharks are now threatened. To be able to protect sharks, we need to know them better.
Sharks are cartilaginous fish who have reigned supreme in all oceans for more than 400 million years. There are 375 shark species, 5 of which frequently swim in the St. Lawrence River: the basking shark, the Greenland shark, the spiny dogfish, the porbeagle and the great white shark. Sharks have the most highly developed senses of any creature. Their body and fins are supple and light, which enables them to be fast and agile. Their extremely sharp sense of smell allows them to smell a tiny drop of blood in a water volume equal to the volume of a pool. Sharks are avidly voracious and eat fish, invertebrates and sea mammals. They hold an essential role in maintaining marine ecosystems in balance because they are at the top of the marine food chain and act as stabilisers for the populations they feed on.
Sharks arouse terror. However, most of them are harmless to humans. In most cases, shark attacks happen when a shark feels threatened or mistakes a swimmer for a prey. Around the world, about 80 people are attacked by a shark every year. Of these attacks, less than 10 are deadly. On the other hand, the threat posed by humans on sharks is relentless: overfishing, pollution, incidental catch and finning cause the disappearance of 100 million sharks every year around the world. Many species are now in danger of extinction, including the great white shark and the spiny dogfish.
So, are sharks threatening… or threatened?
Visit Exploramer to learn more about sharks and species found in the St. Lawrence River.
A new activity entitled “Science feature: Sharks” will show you the true nature of sharks.