Turkish Journal of Fisheries and Aquatic Sciences
2012, Vol 12, Num, 2 (Pages: 239-246)
Fishery Characteristics and Population Dynamics of Indian White Shrimp, Fenneropenaeus indicus from Arabian Sea, Sultanate of Oman
Sahar Fahmy Mehanna 1 ,Juma Al-Mamary 1 ,Lubna Al-Kharusi 1
1 Marine Sciences and Fisheries Centre Muscat, Oman
DOI :
10.4194/1303-2712-v12_2_07
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Monthly carapace length frequency data of Indian white shrimp Fenneropenaeus indicus were collected from
commercial cast net catch from the Omani waters of the Arabian Sea at Al-Mahout fishing area. Sampling covered the first
three months of the shrimp fishing season from September to November during two years 2010 and 2011, where more than
95% of shrimp catch was landed. FiSAT software program was used to analyze its length frequency distribution. The size
structure of F. indicus is characterized by sexual dimorphism, where females are significantly larger than males. Allover sex
ratio was slightly in favor of females with an overall sex ratio 1:1.1 in 2010 and 1:1.28 in 2011. Growth parameters (K and
L∞) were estimated based on age-length data obtained from Bhattacharya method (1967). Also, the instantaneous rate of total
mortality (Z), natural mortality (M) and fishing mortality (F) were estimated and accordingly the exploitation ratio was
determined as F/Z. Per-recruit analysis showed an overfishing situation for F. indicus in Oman and the present level of
exploitation rate should be reduced by about 12% to achieve the maximum yield per recruit and by about 50% to maintain a
sufficient spawning biomass. To overcome any bias in our estimations, we suggest a gradual decrease in fishing effort starting
by 10% and make year-to-year analysis to adjust computations of fishing mortality and age at first capture.
Keywords :
Indian white shrimp; Fenneropenaeus indicus; Arabian Sea; population dynamics; management