BEH-Eco-4

Currently, most aquatic ecosystems (both standing and flowing waterbodies) are exposed to
multiple stressors (drainage and straightening, groundwater extraction, disruption of
longitudinal connectivity, nutrient enrichment and pollutant inputs, neobiota etc.), which lead
to significant losses of native biodiversity in and around water bodies. As a result, watercourses
are among the most endangered ecosystems worldwide and are experiencing a disproportionate
decline in biological diversity. For example, 37% of native fish species and 23% of amphibians
in Germany are classified as ‘endangered’, ‘highly endangered’ or ‘threatened with extinction’.
Similar to vertebrates, many invertebrates are also highly endangered (e.g. molluscs 23%,
stoneflies 46%, mayflies 41%). The European Water Framework Directive (EU WFD) has been
counteracting this development since 2000, with one of its goals being to bring all surface
waters in Europe to a good ecological and chemical status by 2027.
The lecture covers key theoretical principles of aquatic ecology, with a focus on freshwater
ecosystems. In the practical part, which is accompanied by a seminar, a faunistic inventory and
limnological assessment of flowing waters is carried out. The investigated stream sections
include structurally degraded and chemically impacted reaches as well as near-natural and
protected sections. The aim is to analyze relationships between the ecological and
ecotoxicological condition of the water bodies and their chemical, physical and structural
characteristics.