علوم زیستی دریا
Khatereh Mehrabani; Mohammad Khosravizadeh; Vahid Yavari; Seyed Mehdi Hosseini; Omid Beyraghdar Kashkooli
Abstract
The aim of this study was to estimate the amount and species composition of discards in bottom trawl fisheries in the Bosif fishing ground in the coastal waters of Khuzestan. Furthermore, the biological parameters of discarded species were assessed. Specimens were collected from commercial catch data ...
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The aim of this study was to estimate the amount and species composition of discards in bottom trawl fisheries in the Bosif fishing ground in the coastal waters of Khuzestan. Furthermore, the biological parameters of discarded species were assessed. Specimens were collected from commercial catch data of trawl vessels in three seasons, autumn and winter 2017 and summer 2018. The results showed that discarded samples included 33 species from 28 families. Orangefin Pony fish and striped piggy species were the most frequent species in this study. The results also showed that the mean length of most of the discards species was below 30 centimeters. The amount of discards per unit of catching effort was 57.33±9.87, 27.50±16.64 and 32.33±7.50 in the autumn, winter and summer seasons, respectively. The catch per surface area in autumn, winter and summer were 2.77 ± 0.064, 0. 73 ±0.39 and 1.73 ± 0.44 kg/nm2, respectively. The results showed that CPUE and CPUA in winter were significantly higher than those in autumn and summer (p<0.05). In general, the results of this study represent high fishing pressure on ecologically important species in Bosif fishing ground especially in their critical life cycle which may affect local ecosystem structure and function in future.
علوم زیستی دریا
Mohammad Khosravizadeh; Ainaz Khodanazary; vahid Zareii
Abstract
Different stunning/slaughtering methods could significantly influence flesh quality of fish during storage time. Hence, the aim of present study was to explore the effects of two stunning/slaughtering methods including electroshock and asphyxia in the air on sensory, microbiological and chemical alterations ...
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Different stunning/slaughtering methods could significantly influence flesh quality of fish during storage time. Hence, the aim of present study was to explore the effects of two stunning/slaughtering methods including electroshock and asphyxia in the air on sensory, microbiological and chemical alterations of silver carp during 5 days storage in ice. The results showed a gradual increase in counts with time for mesophilic and psychrophilic bacteria in both methods. However, comparing the results showed mesophilic and psychrophilic counts were significantly lower in fish stunned by electroshock methods at the end of study. In case of chemical characteristics, no significant differences between two stunning/slaughtering methods were observed. Also the results of sensory analysis did not show significant differences between the two methods and quality index was highly correlated with time during ice storage. Hence, despite of no significant differences in chemical and sensory characteristics, the results showed growth rate and total counts of bacteria were significantly lower in fish slaughtered by electroshock.