Algae and hydropower. Attached algal vegetation as indicator of disturbances of the lotic ecosystem
The aim of this article is to present an approach (modus operandi) for producing recommendations regarding potential hydropower development. A study of attached algae in 27 streams in mid Sweden according to extension of hydropower or not was carried out. The samples were taken already in 1982 and some of the streams and parts of rivers have been protected since then and are not subject to development. On the other hand, some of the unregulated sites have been developed for hydropower. Species of attached algae (periphyton, benthic algae) were used as indicators and together with the approach of clustering and polar ordination for showing connections or disconnection between sites it resulted in four classes according to degree of action (protection or extension). The theory of island biogeography has been used as one of the main reasons for not developing more hydropower. The main contribution is to point out the importance of saving most rapids not affected by regulation since most large and middle-sized rivers in our country (and the rest of the world) are developed for hydropower and consequently the normal torrential flora (and fauna) is very vulnerable.