Fish is a popular meal for many people.

It's healthy, tasty and often cheap because there are lots of fish in the sea.

But are there? Perhaps you've noticed that sometimes we can't buy our favourite fish.

The reason is that in the last thirty years we've taken too many fish out of the sea.

Fishermen must stop catching some fish for a while and catch others instead.

Man has caused lots of problems to other sea animals too.

There aren't many sea turtles left in the world.

People kill them for food and many also die when they get caught in fishermen's nets.

Another problem for turtles is that they lay their eggs on beaches.