08 maig Threats to biodiversity and ecosystem processes derived from climatic events.

If you look  the stones and sediments of a river you can see different small organisms: snails, worms, dagroflies, scuds, stoneflies… they are insects, molluscs,  crustaceans, oligochaetes, among others, and they are known as macroinvertebrates. Macroinvertabrate communities can give a lot of information on ecological quality in freshwater ecosystems. The diversity, abundance and biomass of these organisms can be used as indicators of alterations due to human activity or environmental processes. It is accepted that high diversity and the presence of some species are indicators of good water quality because certain species are very sensitive to the presence of chemical substances, temperature, low levels of oxygen and other alterations in frashwater ecosystms related with human activities or climatic changes. During the last CLIMALERT sampling campaign in Algars river (at the end of February 2019) the community of macroinvertebrates was sampled in to identify the threats posed by climatic events (droughts and floods) on biodiversity and ecosystem processes. The study was focused on two of the sampling points that compose the sampling network in Algars river, these two sampling points are charachterised by different degree of human impact in the river basin.

Julio Lopez-Doval from the Catalan Institute for Water Research (ICRA) is studying these possible effects on the macroinvertebrate community and below you can see some of the organisms found during this sampling campaign. In the picture A you can see a dargonfly, in B a caddisfly, in the picture C a group of mayflies and finally in D a group of stoneflies. All the pictures were taken with a stereomicroscope.