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Title: Population dynamics of grey mullet species (Liza aurata and L. saliens) in the Southern Caspian Sea
Author: Ghadirnejad, H.
Awarding Body: University of Wales Swansea
Current Institution: Swansea University
Date of Award: 1997
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An introduction is given to the Caspian Sea, grey mullet species, and the grey mullet fishing method in the southern Caspian Sea, together with an introduction to the quantitative assessment in the fishery. 11,614 specimens of the grey mullets Liza aurata and L. saliens were collected from the catches being obtained at 91 sample sites along the Iranian side of the Caspian Sea in the fishing seasons 1993-94 and 1994-95. The specimens were identified by a rapid identification method. Basic biometrical measurements were recorded from the whole sample and a further set of measurements from a subsample of 1301. Scales and otoliths for age determination were collected. The age of all specimens was determined by scales, and an improved method for removing the otoliths was developed. The growth and morality of L. aurata and L. saliens were estimated by several methods. Biomass and maximum sustainable yield for both species were estimated by using different methods. Removed stomach contents were examined and food items identified and counted. Frequency of occurrence (F%) and numerical percentage (N%) methods for quantifying food items in the stomachs were employed. Ovary maturation and fecundity of L. aurata and L. saliens were investigated and compared with the results of other studies. Finally recommendations have been made to help the Iranian fishing managers exploit the grey mullet species in the Caspian Sea whilst conserving the present biomass.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available