Station 10 - English
From the source to the mouth
Precipitation flows off especially quickly from rocky hills such as those in the Eifel. This results not only in fast-flowing brooks, but also in sections of brooks with little or no water during dry periods, which must thus be repeatedly recolonised by brook inhabitants. This is possible only if the entire watercourse, from the source to the mouth, is free of barriers and provides suitable living conditions.
Sensitive biological communities
Sections of a watercourse which can no longer be reached by brook trout, for example, cannot support freshwater pearl mussels, because the very territorial pearl mussel requires the brook trout as a host fish for its larvae. The larvae attach themselves to the gills of brook trout, and only there develop into young mussels, over a period of several months.
Living water filters
Pearl mussels filter minute food particles from the water. In our latitudes the pearl mussel can live almost one hundred years, and during its lifetime filters over half a million litres of water, thus performing an important purification function. On the other hand, for this reason the pearl mussel is particularly sensitive to environmental pollutants and the contamination of brooks.
Lifelines for human beings and nature
Healthy brooks and rivers are the lifelines of the countryside. Where we preserve their natural characteristics, we enable them to provide many benefits to us – for example, clean drinking water and effective protection against flooding.
However, it is not enough for us to maintain untamed flowing bodies of water in their original state only in nature protection areas. All of us can contribute in our own working and living environment, because the protection of water begins in our own back yard.
• Carefully considered release of young fish
Young fish are frequently released in ponds or flowing bodies of water. If this is done in an imbalanced manner or, for example, with too many trout, it has somewhat harmful effects on other fish species or on the larvae of aquatic insects. Diseases can also be introduced in this way. Of course the release of fish is forbidden in the National Park.
• Dead wood in the brook
Many people feel that fallen tree trunks and other types of dead wood in brooks are objectionable. The opposite is true: Dead wood creates calm water zones, sand and gravel banks, and other microhabitats in the brook. Like a filter, the dead wood traps plant material and soil that has been washed away. It also provides food for small organisms.
• Avoid channelling and the use of pipes
Human intervention via the use of pipes or the construction of even the smallest dams causes considerable harm to brooks. The flow speed, oxygen content and temperature of the water are changed. Species of small fish, aquatic insects and other invertebrates are severely disrupted in their natural drive to migrate up the brook.
• Avoid sealing the soil in your own garden
In Germany, every day soils are sealed over an area amounting to the size of 140 football pitches. This means that precipitation can no longer seep into the ground, and that constantly increasing volumes of water must be accommodated by brooks and rivers. This not only harms the flowing bodies of water, but also results in increasingly dangerous flooding.
• Establish verges along brooks
In places where fields or grazing areas extend directly to a brook, not only mud but also residues of fertilisers and pesticides are continually washed into the water. Only a broad verge, with natural wooded banks, can form an effective barrier against these pollutants.
• Do not wash automobiles near brooks or rivers
Domestic waste water still frequently flows directly into brooks or rivers. Although this is prohibited, waste water and oil residues from the washing of automobiles still enter bodies of water via rainwater drainage. The chemical residues can rapidly exceed the purification capacity of a brook. A single drop of oil contaminates 1000 litres of water.