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Objective of the present study was to assess effects of pre‐freezing ice storage and duration of frozen storage on proximate composition and microbial parameters of fish. Thirty‐six samples of pond raised silver carp were divided into three groups. Samples in Group 1 were immediately subjected to frozen storage at −18ºC, those in Group 2 and Group 3 were stored in ice for 3 and 5 days, respectively, prior to freezing. In samples of Group 3, initial protein content (20.09% ± 0.44%) of fish muscles significantly decreased to 17.71% ± 0.87% (p < .05) after 60 days of frozen storage that further reduced to 17.10% ± 0.28% after 90 days. Samples in Group 1 and Group 2 showed significantly reduced protein content after 90 days of freezing. Total coliform and fecal coliform count was found to be higher than the maximum proposed limits in samples of Group 3. Practical applications Fish food industry has to deal with the challenge of seafood quality preservation to comply with consumer expectations. Due to lack of frozen storage facility in our fish markets, fish is stored in ice for variable duration. Results of present study indicate that condition of fish prior to freezing significantly influences its quality during frozen storage. Moreover, interactive effect of pre‐freezing ice storage and frozen storage duration on fish quality implies that storage of fish in ice will intensify its microbial and enzymatic spoilage during freezing.

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Pond bottom soil quality is an interesting area to assess environmental impact of aquaculture. Aim of the present study was, therefore, to investigate effects of fish culture on quality of pond bottom soil. Ten excavated earthen ponds located in Lahore, Pakistan were divided into two groups; Group1: 23-32 years old and Group 2: 8-20 years old ponds. Mechanical and chemical methods were used to study particle size distribution and physico-chemical attributes of soil respectively. Surface sediment of ponds contained higher sand and lower clay content than that of deeper soil layers in both groups. pH of the soil was higher than 7.0 that ruled out the necessity to lime soil for neutralizing acidity. Salinity of surface soil was found to be significantly high (P<.05) compared to that of deeper layers. Organic carbon in surface soil of Group 1 ponds (3.35%) was significantly higher (P<.05) than that of Group 2 ponds (2.60%). Available phosphorous represented only 1-10% of total soil phosphorous. An interactive effect of pond age and soil depth was found on soil clay and electrical conductivity through factorial analysis. Results led to the conclusion that regular removal of sediment can maintain original quality of bottom soil.