Assessing angling catches in dam reservoirs on the example of Zegrze Dam Reservoir [RESEARCH ARTICLE]

Abstract

Three methods were used to estimate the size and structure of angling catches in Zegrze Dam Reservoir in the 1999-2001 period. The material analyzed comprised data collected from direct monitoring (798 times), 153 questionnaires, and 687 reports. The catch structure according to the questionnaires and direct monitoring was similar. Recreational anglers who completed the questionnaires reported catches of 14 fish species; three of these (bream, Abramis brama (L.), roach, Rutilus rutilus (L.), and white bream, Abramis bjoerkna (L.)), comprised 51.6% of the total catch weight. The share of predatory fish comprising pike, Esox lucius L., pikeperch, Stizostedion lucioperca (L.), and wels, Silurus glanis L., was 31.1% of the total catch weight. The anglers who were monitored directly caught 12 species of fish, and bream dominated the catch weight at 55.0%. The share of predatory species was 33.4%. The anglers using the fishing camps demonstrated the greatest interest in predatory species, which comprised a total of 35.4% of the overall biomass of their catch. The estimated size of the catch according to questionnaires was 42842 kg or 13.0 kg ha-1, while the fishing intensity was 0.20 kg fisher-1 hour.-1. According to direct monitoring, the size of the annual catch was 33544 kg, which corresponds to an effectiveness of 10.2 kg ha-1. The results indicate that the questionnaire and direct monitoring methods are compatible, and that it is generally necessary to choose uniform study methods. When using the questionnaire method, it is essential to verify the results obtained through direct monitoring at the fishing grounds. The method of catch reporting by the fishers using the fishing camp is only of auxiliary significance.

CORRESPONDING AUTHOR:

W. Wiśniewolski [+], I. Borzęcka
Department of River Fisheries
The Stanisław Sakowicz Inland Fisheries Institute in Olsztyn
Główna 48, Żabieniec, 05-500 Piaseczno, Poland;
Tel./Fax: +48 22 7562044,+48 22 7562088;
e-mail: rzeki@infish.com.pl
A. Wołos
Department of Fisheries Bioeconomics
The Stanisław Sakowicz Inland Fisheries Institute in Olsztyn, Poland