Description Freshwater habitats

Since 1950 the "nature quality" of many waters has declined. This decline is caused by changes in water quality, natural dynamics, transitions from water to land and the construction of barriers in water bodies.

Introduction

There is a wide range of freshwater habitats in the Netherlands: flowing or stagnant, eutrophic or oligotrophic, deep or shallow. The types of water bodies that occur naturally in the Netherlands include streams and rivers. But many of the freshwater habitats are man-made: ditches, canals, and the Lake IJssel with its marginal lakes.

The freshwater bodies are home to a wide variety of plant and animal species. However, the Natural Capital Index (NCI, an indicator of biodiversity of nature, based on the state of a number of representative species in a certain habitat) of many of these bodies has fallen sharply since 1950. The reasons are the changes in water quality, natural dynamics and transition from water to land, and also the construction of barriers in water bodies. Furthermore, certain exotics have established in fresh water.