Catch per Unit Effort and Size Composition of Crayfish, Astacus leptodactylus Eschscholtz 1823, in Lake İznik

Abstract

This paper was carried out from 15 June to 24 December in 2000 in Lake İznik of Turkey, to determine catch per unit effort (CPUE) and size composition of crayfish, Astacus leptodactylus Eschscholtz 1823, captured by fyke-nets of local fishermen. The average CPUE of all size groups was found as 1.65 crayfish/fyke-net/night for fishing season in 2000, but 26.4% of which was below the legal minimum size (crayfish<90 mm). The average CPUE of legal-sized (crayfish≥90 mm) crayfish was 1.10 crayfish/fykenet/night. The annual catch of crayfish was estimated as 2990 tonnes. The length and weight compositions of crayfish captured in the fyke-nets have varied between 60 and 130 mm, and 6 and 71 g, respectively. The mean length and weight were found as 95.5 mm and 28.8 g for all size groups and 100.1 mm and 33.0 g for legal-sized individuals.

Recovering Turkish narrow clawed crayfish (Astacus leptodactylus) populations carryAphanomyces astaci

“…Crayfish plague epidemics started in Turkey 1985 and devastated most of the native narrow clawed crayfish stocks. Lake İznik stock has been considered productive before the epidemics and was one of the few stocks that has been producing commercially even after the epidemics, with an estimated annual production of 80-245 ton (Baran and Soylu, 1989b;Balik et al, 2002;Harlioğlu, 2004) and an estimated CPUE from 1.13 to 2.18 in year 2000 survey (Balik et al, 2002). The stock in Lake İznik has shown gross symptoms of infection, melanised lesions and tissue erosion, since 1980's epidemics (Harlioğlu, 2008).…”

Trend Analysis and Comparison of Forecast Models for Production of Turkish Crayfish (Pontastacus leptodactylus Eschscholtz, 1823) in Turkey

“…In Turkey, there are many researches on freshwater crayfish mainly focusing on biology and reproduction (Balık et al, 2005 andBalik et al, 2005;Berber and Balık, 2006;Berber et al, 2010;Harlioğlu et al, 2012;Bök et al, 2013;Bolat and Kaya, 2016;Harlıoğlu et al, 2018), population dynamics (Bolat, 2001;Berber et al, 2012;Yüksel et al, 2013), fisheries technology (Balık et al, 2002 and2003;Bolat et al, 2010), genetic (Akhan et al, 2014), and polyculture (Berber and Kale, 2018;Berber et al, 2019).…”

A study on the morphometric characteristics ofAstacus leptodactylusinhabiting the Thrace region of Turkey

“…Allometric or relative growth patterns in various crayfish species have been observed widely (Skurdal and Qvenıld, 1986;Pursiainen et al, 1988;Huner et al, 1990;Correia, 1993;Garvey and Stein, 1993;Austin, 1995;Gillet and Laurent, 1995;Romaire et al, 1977;Acosta and Perry, 2000;Eversole et al, 2006;Rajkoviċ et al, 2006). For example, A. leptodactylus was studied in Mogan Lake by Karabatak and Tüzün (1989), in Ayrancı Dam Lake by Erdem (1994), in the Agın region of Keban Dam Lake by Harlıoglu (1999), in Keban Dam Lake (Duman and Gürel, 2000), in Beyşehir Lake by Erdemli (1982), in Hotamış Lake and in Mamasın Dam Lake by Erdemli (1987), in Dikilitaş Reservoir by Köksal et al (2003), inİznik Lake (Balık et al, 2002), in the Lakes of Akşehir, Eber and Apa Dam Lake (Erdemli, 1982), and in Egirdir Lake (Balık et al, 2002). Formerly, in the region of Thrace, Güner (2006) studied the length-weight relationship in A. leptodactylus inhabiting Terkoz Lake and Deval et al (2007) examined the age determination of A. leptodactylus for some habitats which we examined for this study.…”