Overfishing

People have caught, and eaten, fish for thousands of years. When we have taken fish out of the oceans of the World, new fish have been born to replace them. The fish have reproduced as fast as we have fished. So, the number of fish in the ocean has been about the same. The stocks have been stable.

But this is not true anymore. During the 20th Century, the population of the World grew quickly. More people needed more food, and much of that food was taken from the ocean. We started to use more efficient methods of catching fish. The nets were made stronger, and larger.

And using modern technologies, the boats could find the shoals more easily. In place after place, we caught so many fish, that they couldn’t reproduce fast enough. The stocks of fish in the oceans diminished. This is called overfishing. And overfishing has a huge impact on many fish species in the ocean.

Only 20 percent of cod remains, compared to the year 1900. Five percent of the world’s tuna remains. One percent remains of the world’s eel. In the ocean there are many different kinds of animals. They eat, and get eaten.

The smallest fish eat algae, plankton, and small shrimp. Larger fish eat the smaller fish. And very large fish eat those medium sized ones. We humans prefer to eat large fish, so when a fishing vessel comes with its trawl nets, it mostly catches the large predator fish. When the large predator fish become fewer, more of their prey survive - the medium sized fish.

When the medium sized fish become more numerous, they eat more small fish than usual. And when they become fewer, algae and plankton grow, since they’re not eaten. So, overfishing doesn’t only hit the species that we fish. It affects whole ecosystems in the ocean. But nothing of that is visible at the surface.

The water looks like it always has, even though a lot has changed below the surface. We are disturbing the ecosystems of the ocean, and are very close to eradicating several large fish species. And this is a problem, not only to life in the ocean, but also for us humans. A large part of the world’s population is dependent on fishing to survive. But it’s still possible to do something about this.

In several places around the world, authorities or fishing companies have decided to halt the fishing. In these places we can see that the fish recover, and the stocks start to grow again. So, the stocks of fish in the ocean can recover - if we give them a chance.