Population and fishing of carp (Cyprinus carpio L., 1758) in Yeniçağa Lake

SUMMARY Population and Fishing of Carp {Cyprinus carpio L., 1758) in Yeniçağa Lake Lake Yeniçağa is located in province of Bolu and plays an important role as providing fish and recreational area for the local people.This study was carried out between March and November 2002 and it was aimed that to analyse the population structure, the growth characteristics, the identification of reproduction characteristics as well as the fishing activities of common carp {Cyprinus carpio L., 1758). It was determined that; i) sample size from the population was 281 fishes in total and consist of 148 males and 133 females, ii) ages ranged between I. and XTV., iii) total lengths ranged between 19 and 77 cm, and iv) weights changed between 188-7798 g. Length- weight relationship was calculated as W = 0.0299 L2'8439 (r =0.9353), age-length relationship was calculated as L=l 11.54 [1-e"00690 ], while age-weight relationship was determined as Wt= 19874.96 [i_e-°°690(t+21620>]2-8439. The mean Condition Factor (K) that was found as 1.62 ± 0.02 and showed its highest value in October and lowest value in July. It was found that the first sexual maturity has started from the age of four in both sexes and the spawning activity has occured between May and July. It was identified that the trammel net was in commonly used in commercial fishing in the lake. The proportions of the fish caught using the net in the sampling days were found as 62.86 % common carp, 21.53 % tench {Tinea tinea), 10.06 % carassius (Carassius carassius ) and 5.55 % chub {Leuciscus cephalus). Key Words: Yeniçağa Lake, Carp, Cyprinus carpio, Growth, Reproduction, Condition Factor, Gonadosomatic Index, Fishing VI