Population Dynamics of the African River Prawn, Macrobrachium vollenhovenii, in Dawhenya Impoundment
Abstract
Studies were conducted on the growth and mortality parameters, recruitment pattern, probability of capture, yield-per recruit, and present rate of exploitation of the African river prawn, Macrobrachium vollenhovenii from Dawhenya impoundment, Ghana. Estimation of the von Bertalanffy growth parameters gave; L∞ = 14.2 cm, K = 1.0 yr -1 , and to = -0.195 yr -1 with the growth performance index, Ф' of 2.303. From the linearised length-converted catch curve, total mortality, Z was 5.36 yr -1 . Natural mortality, M calculated from Pauly's empirical formula was 2.20 yr -1 and fishing mortality, F calculated from Z - M was 3.16 yr -1 . From the mortality estimations, the present rate of exploitation, E calculated from F/Z was 0.59 indicating that, the species is on the verge of being over-exploited in the impoundment. Using the estimated value of the growth coefficient, K, the longevity was found to be about 3 yrs. Estimations from the probability of capture routines gave the length-at-first capture, Lc as 3.07 cm while the size distribution of the catches suggest two recruitment pulses in a year. It is therefore recommended that, the property right-based system for fisheries management should be implemented so that fishermen can cooperate in the management of the Macrobrachium fishery.
Keywords
Population Dynamics of the African River Prawn, Macrobrachium vollenhovenii, in Dawhenya Impoundment
Abstract
Studies were conducted on the growth and mortality parameters, recruitment pattern, probability of capture, yield-per recruit, and present rate of exploitation of the African river prawn, Macrobrachium vollenhovenii from Dawhenya impoundment, Ghana. Estimation of the von Bertalanffy growth parameters gave; L∞ = 14.2 cm, K = 1.0 yr -1 , and to = -0.195 yr -1 with the growth performance index, Ф' of 2.303. From the linearised length-converted catch curve, total mortality, Z was 5.36 yr -1 . Natural mortality, M calculated from Pauly's empirical formula was 2.20 yr -1 and fishing mortality, F calculated from Z - M was 3.16 yr -1 . From the mortality estimations, the present rate of exploitation, E calculated from F/Z was 0.59 indicating that, the species is on the verge of being over-exploited in the impoundment. Using the estimated value of the growth coefficient, K, the longevity was found to be about 3 yrs. Estimations from the probability of capture routines gave the length-at-first capture, Lc as 3.07 cm while the size distribution of the catches suggest two recruitment pulses in a year. It is therefore recommended that, the property right-based system for fisheries management should be implemented so that fishermen can cooperate in the management of the Macrobrachium fishery.
Keywords
Details
| Primary Language | Turkish |
|---|---|
| Journal Section | Articles |
| Authors | |
| Publication Date | February 1, 2011 |
| Published in Issue | Year 2011 Volume: 11 Issue: 1 |