The faecial contamination of silver cyprinid (rastrineobola argentea) sundried on nets laid on grass at Katosi landing site Mukono district
Abstract
Rastrineobola argentea, a small pelagic fish known as the Silver cyprinid and commonly
referred to as ‘Mukene’ ranks among the top three species landed from Lake Victoria. It is
majorly preserved by sun drying on surfaces such as net- on grass, net- on ground and ranks
with the commonly used being net-on grass. Studies show that this particular surface has higher
microbial loads thus poses a high risk of contaminating the sun dried fish. This study evaluated
whether the location of the nets on grass had a significant effect on the level of fecal
contamination on the sun dried fish. Three net locations were evaluated i.e. shore, mid-point
and upland at Katosi LS. Wet and dry samples were collected on randomly selected nets at the
three different net locations. Dry samples were collected after 8 hours on the same nets from
which the wet samples were initially collected at the three different nets locations. The samples
were analyzed for fecal contamination by examining for Escherichia coli and Enterococci fecal
indicators. The findings showed that generally the location of nets laid on grass had a less
significant effect on the level of fecal contamination. However this was greatly influenced by
the kind of fecal indicator species examined because the level of fecal contamination with
Enterococci on sundried Silver cyprinid significantly varied at the three different locations.
This showed a contradiction from the findings found in examining the dry samples for E.coli
because the results indicated the level of contamination was significantly the same at the three
net locations. Previous studies indicate that Enterococci is not purely found in human and
animal fecal matter but can also be found on plants and in soil with evidences that Enterococci
cells are capable of replicating in extra-enteric environments such as beach sands. Further
studies to eliminate the possibility of human fecal contamination from the other environmental
sources of the organisms which was not determined in this study is thus required.