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首页> 外文期刊>Indian Journal of Fisheries >Fishery, population characteristics and yield estimates of coastal tunas at Veraval
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Fishery, population characteristics and yield estimates of coastal tunas at Veraval

机译：韦拉瓦尔沿海金枪鱼的渔业，种群特征和单产估计

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摘要

The fishery, population characteristics and yield estimates of coastal tunas Thunnus tonggol, Euthynnus affinis and Auxis thazard at Veraval were studied during 2003 - 2006. The average annual catch was 731 t, which contributed to 28% to the total gillnet catches. The main species of tunas landed were T tonggol (46.8%), E. affinis (17.5%), Thunnus albacares (6.4%) and A. thazard (5.2%). E. affinis and A. thazard exhibited isometric growth but for T tonggol it was allometric. The von Bertalanffy growth equation was L-t = 107.4 [1 - e(-0.18(t+0.0729))] for T. tonggol, L-t = 72.5 [1 - e(-0.56(t+0.0327))] for E. affinis and L-t = 46.6 [1 - e(-0.93(t+0.0153))] for A. thazard. The mortality rates M, F and Z for T. tonggol were 0.4, 0.72 and 1.12 respectively, while for E. affinis and A. thazard, the values were 0.94, 1.48 and 0.75 and 4.49, 1.69 and 5.97, respectively. The exploitation ratios for T. tonggol, E. affinis and A. thazard were 0.64, 0.44 and 0.75 respectively. The higher exploitation rate and lower MSY in T tonggol and A. thazard was an indication of intensive fishing and overexploitation of these speceis. But for E. affinis, the exploitation rate was low and MSY was high indicating further scope for exploitation. Reducing the present fishing effort by 40%, maximum relative yield was realized for T. tonggol and A. thazard but for E. affinis, increasing the fishing effort by 80% provided the maximum relative yield.
机译：在2003年至2006年期间，研究了Veraval沿海金枪鱼Thunnus tonggol，Euthynnus affinis和Auxis tazar的渔业，种群特征和单产估计。年平均捕捞量为731 t，占刺网总捕捞量的28％。登陆的金枪鱼的主要种类是T tonggol（46.8％），affinis（17.5％），Thunnus albacares（6.4％）和A. tazar（5.2％）。亲和肠杆菌和危险链霉菌显示出等长的增长，但是对于通哥T而言，它是等长的。冯·贝塔朗菲的生长方程对于tonggol是Lt = 107.4 [1- e（-0.18（t + 0.0729））]，对于E. affinis是Lt = 72.5 [1- e（-0.56（t + 0.0327））]。 L. = 46.6 [1- e（-0.93（t + 0.0153））]。桐木的死亡率M，F和Z分别为0.4、0.72和1.12，而亲子肠杆菌和A. tazar的死亡率分别为0.94、1.48和0.75和4.49、1.69和5.97。桐木，亲和肠杆菌和危险曲霉的开发利用率分别为0.64、0.44和0.75。 T tonggol和A. tazar的较高的开发利用率和较低的MSY，表明这些物种密集捕捞和过度开发。但是对于亲子肠杆菌，开发率较低，MSY较高，这表明有进一步的开发空间。将目前的捕捞努力减少40％，就可以将通g和A. thazard的最大相对产量提高，但将嗜血肠球菌（E. affinis）的捕捞努力提高80％，就可以实现最大的相对产量。

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