Exchange rate and small-scale movements of fish between a river and its backwater
Archiv für Hydrobiologie Volume 147 Number 4 (2000), p. 485 - 504
published: Feb 11, 2000
ArtNo. ESP141014704006, Price: 29.00 €
Movements of four freshwater fish species, pike (Esox lucius), roach (Ruti-lus rutilus), rudd (Scardinius erythrophthalmus) and perch (Perea fluviatilis), were studied in a backwater (1.2 ha) of the River Morava (Czech Republic), consisting of five pools permanently connected to each other and to the river. Pool-specific finclipping was used to mark fish collected by electrofishing at monthly intervals (March to November 1995). Of the 367 fish marked, 85 were recaptured, giving a return of 23.16 %. Pike and rudd tended to remain in their home pool, with rudd showing higher activity within the backwater than pike. Roach and perch were not resident in the backwater. The ratio between two population estimates, the Schnabel and Seber & LeCren estimates, was used to calculate an exchange rate of fish movement between the river and the backwater. Immigration and emigration was greater in roach and perch, having an average exchange rate of 90-96 % per month and a low number of recaptures. In contrast, pike and rudd were less active, with an exchange rate of 61- 72 % per month.