Microbiology and Spoilage Trail in Nile Perch (Lates niloticus), Lake ...

3 MATERIALS AND METHODS
3.1 STUDY AREA AND SAMPLING PLAN
This work was done at NFQCL-Nyegezi. The study was conducted in three phases. Phase I
study was done on microbiology of on lake water, sediments and newly caught Nile perch,
trials 1-3 respectively, from the fishing grounds. Phase II study consisted of two trials; trial 1
on the shelf life of laboratory iced whole Nile perch and trial 2 on chilled Nile perch fillets.
While phase III study was composed of trial 1 on microbiology of whole Nile perch swabs
and on line fillets, and trial 2, shelf life of establishments chilled Nile perch fillets.
Phases I and II samples were procured from Lake Victoria along Mwanza gulf by trawling
method using Nyegezi Fresh Water Fisheries Training Institute (NFFI) MV Mdiria boat.
Mwanza gulf is a reserved breeding area, figure 2. Trawling was covered between latitude 2 0
28 S and 2 0 32 S; and longitude 32 o 49E and 32 o 50 o E at an average depth of 20 meters.
Samples of whole Nile perch, sediments and water were all sampled at the same time during
trawling. The phase III samples; whole Nile perch swabs, on line fillets and establishments
chilled Nile perch fillets were procured from four establishments (E1; E2; E3 & E4) located in
Mwanza City. All samples were brought and stored at the laboratory chill room/refrigerator
set at 0 to 3 o C prior sub sampling laboratory test samples for subsequent analyses.
Figure 2: Sketch map of the South-East part of Lake Victoria. Fishing grounds of the various
landing sites are indicated by shading. S: Semba; I: Igombe and K: Kayenze, (FAO, 2009).
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