Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2003.1046.1050JewelM.A. S.AffanM. A.KhanS. 122003612Cyanobacterial bloom and fish mortality in ponds and lakes are common in Bangladesh
but the relationship between the two has been rarely studied. In April 2002, mass
mortality of fishes occurred in a farmer’s pond of Mymensingh, Bangladesh. At the time
of fish kill, a massive bloom of cyanobacteria (210.5×103 cells ml‾1) was found in the
pond. Microscopic study showed the dominance of Aphanizomenon flos-aquae (L.) Ralfs
and Microcystis aeruginosa, Kütz representing 60.91 and 33.98% of the total
phytoplankton population, respectively. Fish species affected were silver carp,
Hypophthalmichthys molitrix (Valenciennes), tilapia Oreochromis niloticus (L.), catla
Catla catla (Hamilton Buchanon) and common carp Cyprinus carpio (L.) and among
these silver carp, tilapia and catla were severely affected. The gills of dead fishes were
pale-white and the microscopic analysis of the gill squashed water showed the presence
of large number of A. flos-aquae and M. aeruginosa cells. Gut content analysis of dead
silver carp, tilapia and catla revealed the presence of 49.12, 43.5 and 19.35% A. flos-aquae and 30.37, 38.32 and 9.75% M. aeruginosa, respectively among the total
consumed phytoplankton. On the day of fish mortality, high concentration of PO4-P (9.5
mg l‾1), high water temperature (310C) and low dissolved oxygen concentration (0.95 mg
l‾1) were found. The fish mortality was possibly caused either by oxygen deficiency or
toxins secreted by cyanobacteria or by combination of both.]]>Affan, A., S. Khan, M. Imokawa and Y. Ueno,20012001Carbis, C.R., D.L. Waldron, G.F. Mitchell, J.W. Anderson and I. McCauley,1995Microcystis aeruginosa.]]>1371215Carmichael, W.W. and P.E. Bent,19814113831388Collins, M.,197842725746Dahl, E., O. Lindahl, E. Paasche and J. Throndsen,1989Chrysochromulina polyepis Bloom in Scandinavian Waters During Spring 1988.]]>pp: 383-405pp: 383-405Hadas, O., R. Pinkas, E. Delphine, A. Vardi, A. Kaplan and A. Sukenik,1999Aphanizomenon ovalisporum bloom in Lake Kinneret, Israel.]]>2114531469Hynes, H.B.N.,1950Gasterosteus aculaetus and Pygosteus pungitius with a review methods used in the studies of fishes.]]>193658Komarek, J.,1958pp: 10-206pp: 10-206Negri, A.P., G.J. Jones and M. Hindmarsh,1995Anabaena circinalis.]]>3313211329Plamer, C.M.,1964pp: 239-261pp: 239-261Repavich, W., W.C. Sonzogni, J.H. Standridge, R.E. Wedepohl and L.E. Meisner,199024225231Rinne, I. and E. Tarkiainen,197821527546Schwimmer, D. and M. Schwimmer,1964pp: 368-412pp: 368-412Skulberg, O.M. and R. Skulberg,1985Oscillatoria (Cyanophyceae) from Norway: Characterization and classification.]]>71157174Tamminen, T., V. Kaitala, K. Kivi and J. Kuparinen,1985pp: 363-378pp: 363-378Turner, P.C., A.J. Gammie, K. Hollinrake and G.A. Codd,199030014401441World Health Organization,1984Carmichael, W.W., N.A. Mahmood and E.G. Hyde,19901990pp: 87-106pp: 87-106White, A.W.,19881988pp: 914Colman, J.A. and P. Edwards, 19871987pp: 240-281pp: 240-281Tabthipwon, P., O. Chawalit, J. Kugler and J. Moreau,1988Chlorella vulgaris and Microcystis aeruginosa mixed with commercial carp pellets on growth of Nile tilapia (Oreochromis niloticus).]]>1988pp: 387392