This study was carried out to evaluate the impact of untreated urban and industrial effluents on water quality of river Ravi. Water samples were collected from 11 polluted and relatively unpolluted sites at river Ravi during low flow season and analyzed for heavy metals content and physico-chemical parameters. Dissolved oxygen fell below the recommended limit for propagation of fish and other aquatic life as the river flows through Lahore up to Balloki Headworks. Manganese and lead contents were higher than permissible limits for aquatic ecosystems at several polluted sites of the river. Highest concentration of nickel, zinc, manganese, cadmium and lead detected in river water was 20.0 µg/L, 70.0 µg/L, 190.0 µg/L, 2.0 µg/L and 72.0 µg/L respectively. Findings revealed that river water at downstream sites of wastewater carrying drains was not suitable to support fish and other aquatic life due to its very low dissolved oxygen level.

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.

No abstract

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.

Toxoplasmosis is a parasitic disease that is transmitted by a variety of routes, including the ingestion of raw or undercooked meat. It infects roughly one-third of the world's population and is caused by Toxoplasma gondii, an obligate intracellular parasite. The goal of this research is to detect the existence and genotypes of T. gondii in beef and mutton, two of the most widely consumed red meats in Gaza, Palestine, using both ELISA and PCR techniques. For this purpose, 60 red meat samples were collected from butcheries in Gaza city, during the period from January to March 2021. These samples were divided evenly between beef and mutton. This study found that beef is devoid of T. gondii, whether tested using ELISA or PCR. On the contrary, both approaches detected T. gondii in mutton; however, the percentage of positive samples reported differed. For example, whereas T. gondii was detected in 14 (46.66 %) of 30 samples using ELISA, only 5 (16.66 %) of positive samples were detected using PCR. The genotyping results of the current investigation showed that the three DNA isolates were T. gondii type II. A Chisquare test was also implemented to evaluate the prevalence of T. gondii and the type of red meat samples (mutton and beef) examined using PCR and ELISA. Similarly, in the detection of T. gondii, a comparison of the PCR approach and ELISA was conducted, and all of these relationships were shown to be statistically significant, with p values < 0.05. Meanwhile, this investigation found that beef samples were devoid of T. gondii infection. Regardless of whether it was examined with an ELISA or a PCR, this study revealed the occurrence of T. gondii in mutton. The current study also concluded that eating raw or undercooked mutton is a potential risk factor for the transmission of T. gondii infection to humans. Besides, the occurrence of T. gondii type II in the three genotyped ADNA isolates.