Skip to main content
padlock icon - secure page this page is secure

Population statistics of the migratory hilsa shad, Tenualosa ilisha, in Sindh, Pakistan

Buy Article:

$52.00 + tax (Refund Policy)

Summary

In order to estimate the population dynamics of the hilsa shad, Tenualosa ilisha, fishery in Sindh, the key population parameters of growth, mortalities, recruitment pattern, exploitation and maximum sustainable yield are discussed. Length frequency data were collected from April to October 2004 from the main commercial (hilsa) landings at Thatta, Sindh. Estimated parameters of the von Bertalanffy (Hum. Biol. 10, 181–213) growth model were L  = 31.5 cm, = 1.5 year−1, t 0 = −0.10 year as obtained by the electronic length frequency analysis (ELEFAN I). Estimated natural, fishing, and total mortalities were 2.21, 0.673, 2.89 year−1, respectively. The relative biomass per recruit (B′/R) was 0.95 and yield per recruit (Y′/R) was 0.06 using the knife‐edge selection. The exploitation ratio at the maximum sustainable yield (MSY) was E max = 1.0 year−1, fishing mortality at MSY was F max = 2.89 year−1, average target F opt = 0.5 year−1 and F limit = 1.47 year−1. The catch and effort data from 1981 to 2004 (MFD, Karachi) were analyzed using the catch and effort data analysis (CEDA) computer programme. Estimated biological reference point of MSY for the Fox model was 891 tonnes (t), R 2 = 0.75; for the Schaefer and Pella‐Tomlinson models MSY = 744 t, R 2 = 0.49, the outputs of which appeared to be more conservative than the Fox model which indicated a better fit. The overall situation of hilsa fishery is in severe stress and appears vulnerable to overexploitation. On the basis of the present findings, serious attention is required to provide appropriate access of the fish to the Indus River during the spawning period as well as to impose a ban on fishing during upstream migration and on undersized catch to prevent this traditional fishery in this area.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Document Type: Research Article

Publication date: October 1, 2013

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more