Determination of Growth and Mortality parameters for Kawakawa Euthynnus affinis (Cantor, 1849) in Hormozgan Province waters

Growth and mortality parameters for Kawakawa (Euthynnusaffinis Cantor, 1849)were studied using the length frequency composition and biometry of 13716 individuals in Hormozgan province waters in 2013. Length range and mean length range of this species were obtained as 22-85 cm and 59.36 cm, respectively. ELEFFAN I method in FISAT program were used for data analyses.Growth parameters were estimated aslength infinity (L∞) =88.2 cm, growth rate (K) =0.51 year-1 and the age at the length 0 (t0) =-0.23. Overall,eight cohorts were distinguished for kawakawa and maximum recruitment pattern was obtained as 14.48%in August.Total mortalityestimation was found to be Z= 1.87 year-1using catch curve.Natural and mortality coefficients were estimated using the Pauly's formula which resulted in M= 0.64 year-1and F=1.23 year-1, respectively.Exploitation rate (E) was calculated as 0.65 indicating that kawakawa was fully exploited in Hormozgan provincewaters.