Seasonal variation in the trawl codend selectivity of picarel (Spicare smaris)
Abstract Özbilgin, H., Tosunoğlu, Z., Tokaç, A., and Metin, G. 2007. Seasonal variation in the trawl codend selectivity of picarel (Spicare smaris). – ICES Journal of Marine Science, 64: 1569–1572. Seasonal selectivity of commercial 40 mm polyethylene codend was tested for picarel (Spicara smaris) in spring (4–18 April 2002), summer (10–25 July 2002), autumn (26 September–2 October 2002), and winter (22–23 January 2003) in the Aegean Sea. Data were collected using the covered codend technique and analysed using the logistic equation with the maximum likelihood method. Four sets of selection curves were analysed and compared using the model developed by Fryer (1991). Highest L50 is in autumn (13.82 cm; s.e. 0.62), when water temperature is highest and the fish are expected to be in their best condition after summer feeding. Lowest L50 is in spring (11.09 cm; s.e. 0.51), when water temperature is lowest and the fish are at their spawning stage. However, there is not sufficient evidence to say that the seasonal variation in the selectivity of 40 mm polyethylene codend for picarel is statistically significant (p > 0.05).