Fish stocks in the Ancora River, north Portugal food consumption estimated with a bioenergetics model

• Type: Article in International Scientific Journal
• Date: 2000

Authors

Penczak, T (Author) Other; Formigo, N (Author) FCUP

Journal

Title: Fisheries Research

Vol. 49

Pages: 117-128

ISSN: 0165-7836

Publisher: Elsevier

Indexing

Scopus - 4 Citations

Other information

Authenticus ID: P-007-8YV

DOI: 10.1016/s0165-7836(00)00202-2

Abstract (EN): In the 19 km long Ancora River, divided by 20 waterfalls and dams and emptying to the Atlantic Ocean in north Portugal, fish were sampled for the bioenergetics study. Average monthly water temperature during the year at sites along the river course was in the range 8.5-21°C. The four fish populations' consumption, both in energy and mass units, was lower at sites in the middle course of the river, which was isolated from upstream sites by numerous waterfalls and dams. The gross K1 and net K2 ecological efficiencies of brown trout, roach and nase were very low, but detritus was their dominant food item. Eel, which ate animal food only had two to three times higher growth efficiencies than other fish. High mean monthly water temperatures from May to August and the isolation effect were probably the causes of a low utilisation of consumed food for growth in the populations investigated. (C) 2000 Elsevier Science B.V.

Language: English

Type (Professor's evaluation): Scientific