Anmerkung zur Sekundärproduktion von Fischen des Rhithrals

✍ Scribed by Waterstraat, A.

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 478 KB
• Volume: 18
• Category: Article
• ISSN: 0323-4320
• DOI: 10.1002/aheh.19900180304

✦ Synopsis

Anmerkung zur Sekundarproduktion yon Fischen des Rhithrals

S.u,nLmury: I n investigations on the secondary production of flowing waters the share of fish is not paid enough at,tent,ion to. Since the individual species and stages of development occupy different positions in the food pyramid, t.he interpretation of the data is more difficult. As investigations made AS examples at eight stations in three waters show, in some cases species --hose existence is threat.ciied have a. significant share in t'he fish fauna and its production in the undisturbed salnionide region. Considerable changes of the population st'ruct,ure are caused by anthropogenic influences by development and inipoundage. The share of insectivorous fish in the secondary production is discnssed on the basis of data from literature also in comparison with macrozoobenthos. The estimation of the product ion of Cottus gobio in t'wo brooks shows considerable differences in production bptween a eutrophic hard-wat'er brook of ilie lowland and an oligotrophic soft-water brook of t.hc uplands.