<span style="font-size:15.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";mso-bidi-font-family:"Times New Roman"; mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA" lang="EN-US">Estimation of growth, mortality and exploitation of <span style="font-size:15.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";mso-bidi-font-family:"Times New Roman"; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:AR-SA" lang="EN-GB">lesser tiger toothed croaker <i style="mso-bidi-font-style:normal"><span style="font-size:15.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";mso-bidi-font-family:"Times New Roman"; mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA" lang="EN-US">Otolithes cuvieri</span></i><span style="font-size:15.0pt;line-height:115%; font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:AR-SA" lang="EN-US"> (Trewavas. 1974)<i style="mso-bidi-font-style: normal"> </i><span style="font-size:15.0pt;line-height:115%; font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman";mso-ansi-language:EN-GB;mso-fareast-language: EN-US;mso-bidi-language:AR-SA" lang="EN-GB">in Pakistan</span></span></span></span>

Abstract

Four demersal trawl surveys were carried out in Pakistani marine waters in 2009-2010. Length frequency data of 3219 individuals were used to estimate growth, mortality and exploitation, whereas data of 671 individuals were used to estimate length weight relationship in <i style="mso-bidi-font-style:normal">Otolithes cuvieri </i>(Trewavas, 1974). Length ranges from 3 - 35cm and weight ranges from 1 - 208g. Length weight relationship parameters were computed as <i>a</i> = 0.014, <i>b</i> = 2.870 and <i>R²</i> = 0.952. Using the ELEFAN routine of the FiSAT computer package, the calculated von Bertalanffy growth function parameters were <i>L</i>_∞= 36.75cm, K= 0.300/year. Total mortality were computed using length-converted catch curve analysis at Z=1.26/year, whereas natural M=0.740/year and fishing mortality F=Z-M= 0.52/year were calculated. The exploitation ratios (E) were computed as <i>E_max</i> = 0.412, <i>E</i>₁₀ = 0.355, <i>E</i>₅₀ = 0.278. <span style="font-size:9.0pt;line-height: 115%;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:AR-SA" lang="EN-US">The yield per recruit analysis showed that when <i>t_c</i> was 1, <i>F</i>_max was calculated at 0.5 and <i>F</i>_0.1 at 0.4. When biological reference point of <i>F_opt</i> was `M (0.740), current fishing mortality rate of 0.52 is smaller than the target biological reference point.