Though manure has been used for centuries to enhance soil fertility and final agricultural yield, the overuse of fertilizers on the land can cause serious pollution issues, such as heavy metals and eutrophication, that can further lead to health problems. The current study aimed to assess the heavy metals in the most consumed crops (wheat and rice) and fish (common carp) and their risk to human health. Results revealed that there was an irregular trend of heavy metals in different sites of the study area; however, the general trend that was observed during the current research work was Pb>Cr>Cd>Mn in soil samples and crops, while in the case of fish muscle, the trend was Cr>Pb>Cd>Mn. Furthermore, after health index analysis, it was revealed that in some of the sites, the hazard index (HI) was above 1. Principal component analysis suggests a strong positive correlation of the heavy metals from the soil and water to the crops and fish muscles, respectively. Cd was highly bioaccumulated in the crops and fish muscles from different sites. There was an unusual increase in the metal concentration in the samples from the Sargodha. This result suggests a rapid increase in the metal concentration within the agricultural land and its products that can put human health at risk of developing multiple diseases related to the heavy metals, as indicated by the HI values. It is highly recommended that fertilizers should be used carefully so that human populations and animals can safely consume heavy-metal-free food.

Biofloc technology (BFT) is one of the most sustainable aquaculture system, which is based on the principle of nutrient recycling and addition of carbon to enable heterotrophic microorganisms to the system. To evaluate the performance of the biofloc culture system for Cyprinus carpio fingerlings, a 60‐day growth trial was conducted. The fingerlings (n = 600) of average body weight (4.92 g ± 0.14) were stocked in 12 circular fiberglass tanks (300 L, volume 10.59 cft) to form three biofloc treatments (T1, T2, and T3) along with one control group. The carbon sources for treatments were sugarcane molasses, tapioca, and wheat. The C/N ratio of 15 was maintained for all treatments. After 60 days of rearing, the fish were challenged with Aeromonas hydrophila, and the relative percentage survival (RPS) was observed over 14 days. A haematological, nonspecific immune, and stress parameters were analyzed using blood and serum samples collected at intervals of 20, 40, and 60 days. According to the results, the carbon sources affected the water quality parameters but were still adequate for fish welfare. An increased biofloc volume was observed with tapioca. Growth performance and better feed conversion ratio were recorded in biofloc with the tapioca group. The hematological parameters, including haemoglobin (Hb), hematocrit (HCT), white blood cells and lymphocytes were significantly (P < 0.05) higher in biofloc‐based tapioca group than in other treatments and control. Further, the serum protein, globulin, albumin, total immunoglobulin, and respiratory burst activity were also found significantly (P < 0.05) higher in biofloc with tapioca as carbon source. However, the lysozyme activity was higher in biofloc with the wheat group. The RPS in tapioca was significantly higher, followed by biofloc with wheat. In conclusion, the tapioca‐based biofloc can improve C. carpio growth, haematology, and nonspecific immune response under zero water exchange.

The biofloc technology system (BFT) is considered to be one of the sustainable aquaculture systems, which is based on the principle of nutrient recycling with the addition of a carbon source to give dominance to heterotrophic microorganisms. The objective of this study was to evaluate the effect of sugar cane molasses and tapioca flour as carbon sources on the water quality, growth, hematology, immune status, and non-specific antioxidant status of Oreochromis juveniles. Methodologically, the experiment was carried out for 10 weeks on 225 juvenile Nile tilapia with initial body weights of 47.0 ± 1.3 g that were randomly distributed in 09 tanks (1000 L) with a stocking density of 25 tilapias per tank; the treatments were: BFT + SM (S molasses), BFT + TF tapioca flour (TF), and a control with no carbon source added. The control group was fed 100% feed, while the BFT experimental groups were fed microbial flocs along with 75% feed. The results revealed that the water quality parameters were affected by the carbon sources, but were adequate for normal fish welfare, and the biofloc volume was higher (28.94) with the TF carbon source. The growth performance, such as weight gain (98.61), survival (99.01), and improved feed conversion ratio (FCR) (1.69), was recorded in BFT + TF. Significant improvements in WBCs, HCT, HB, lymphocytes, plasma proteins, albumin, and non-specific immune factors (lysozyme activity, immunoglobulins levels, and ACH50) were observed in biofloc-reared fish with tapioca flour as the carbon source compared to the control and sugarcane molasses groups. Moreover, significant increases in catalase (CAT) and superoxide dismutase (SOD) were found in the biofloc-reared fish with different carbon sources. In conclusion, the use of BFT + TF was found to affect improving the water quality, growth, hematology, immunity, and antioxidant status of juvenile Tilapia.

The current study aims to determine the effect of four different anesthetics such as MS-222 (100 mg/L), tobacco extract (50 mg/L), propiscin (1.0 ml/L) and clove oil (40 mg/L) on the hematology and blood biochemical parameters of Labeo rohita. Blood was sampled 10 minutes after the anesthesia was administered and again after 24 hours. Except for the clove oil 24h measurements, there was a significant difference in the number of blood cells in all anesthetic applications (P<0.05). Hemoglobin and hematocrit values were not altered after 24 hours of treatment with clove oil and propiscin. MCV, MCH and MCHC values were not significantly affected in any application except clove oil 24h. Biochemical parameters, including total protein and glucose level, significantly changed (P0.05) with tobacco, Change has been detected in ALP with MS-222 and tobacco calcium and magnesium showed non-significant differences with anesthetics. Overall all the parameters were affected by anesthetics used in the current research, however, it was established that 24 hours following the administration of clove oil, the discrepancies in blood values had vanished to a great extent.