Greener
Journal of  Agricultural Sciences

Vol. 3 (5), pp.
320-331, May 2013.

 ISSN: 2276-7770 

Research
Paper

Manuscript Number: 022613494

 

Effects of water quality, flooding episode and
management variables on the fish yield from self-stocked
ponds in lower Rufiji floodplain, Tanzania

 

H.A. Lamtane^1*, Y.D. Mgaya²   and
R.G. Bailey³

 

¹Faculty
of Agriculture, Sokoine University of Agriculture,
Morogoro, Tanzania

²Department
of Aquatic Science and Fisheries, University of Dar es
Salaam, Tanzania

³28
Duffield Lane Stoke Poges Slough SL2  4AD UK

 

^1*Corresponding
Author’s Email:

hlamtan @ yahoo.co.uk
or hlamtan @ suanet.ac.tz

Abstract:

A

study was conducted to determine fish yields from flood
depended ponds in Rufiji floodplain, Tanzania. Eight ponds
were constructed during dry season in two sites besides two
floodplain lakes, Ruwe and Uba. These ponds were
self-stocked with different fish species from the lakes.
More than eight species were trapped and Oreochromis
urolepis, Labeo congoro and Clarias species were
considered as good candidates for aquaculture. Other small
fish species were harvested immediately after flood
recession and the three key species were cultured for the
maximum of seven months. However, other species in small
quantities were remained in the ponds for the whole period
of experiment. Water quality parameters were monitored
throughout the study period. The relationships between water
quality variables and flooding events were determined using
canonical correspondence analysis (CCA). Other parameters
included in the relationships were fish density, manure and
number of species trapped and cultured. Dissolved oxygen and
pH decreased with time in both sites. Fish yields were
influenced by some water quality, flooding episode and other
management variables. Chlorophyll-a was the only
environmental variable that showed a significant correlation
with fish yield (P< 0.01).  Fish density and number of
species trapped showed a significant effect on the fish
yield (P<0.05). Re-connectivity between ponds and lakes was
strongly positively correlated with yield. It can be
concluded that some water quality variables, flooding and
management parameters were responsible for the observed
yield.

 

Keywords: Flooding, Oreochromis urolepis,
self-stocked ponds, floodplain, fish yield.