* The author is part of the community of readers of La Vanguardia

With the drought, water in the Ter is more scarce than other years, but the presence of crabs, portrayed in La Vanguardia’s Readers’ Photos, is a natural indicator that at least the water is clean and of good quality.

These images have been captured in the Ter as it passes through Manlleu, a town where this river has had great historical importance.

Crayfish live in fresh waters as long as the temperatures do not drop too low and become frozen. They do not like fast currents and are more nocturnal, although these images have been taken in daylight.

The presence of crabs is a good indicator of the quality of the waters even though they are not too demanding in this aspect, but, in this case, they are a good omen of the good health of the Ter as it passes through the Osona region.

Crayfish feed on any organic matter, including carrion. Now, these crustaceans have many predators throughout their lives: insects, fish, birds and mammals, such as the otter.