Fish Pond Sediments Research Articles

Bacterial Communities and Enzymatic Activities in Sediments of Long-Term Fish and Crab Aquaculture Ponds.

Aquaculture is among the most important and fastest growing agriculture sectors worldwide; however, it generates environmental impacts by introducing nutrient accumulations in ponds, which are possibly different and further result in complex biological processes in the sediments based on diverse farming practices. In this study, we investigated the effects of long-term farming practices of representative aquatic animals dominated by grass carp (GC, Ctenopharyngodon idella) or Chinese mitten crab (CMC, Eriocheir sinensis) on the bacterial community and enzyme activity of sediments from more than 15 years of aquaculture ponds, and the differences associated with sediment properties were explored in the two farming practices. Compared to CMC ponds, GC ponds had lower contents of TC, TN, and TP in sediments, and similar trends for sediment pH and moisture content. Sediment bacterial communities were significantly different between GC and CMC ponds, with higher bacterial richness and diversity in GC ponds. The bacterial communities among the pond sediments were closely associated with sediment pH, TC, and TN. Additionally, the results showed profoundly lower activities of β-1,4-glucosidase, leucine aminopeptidase, and phosphatase in the sediments of GC ponds than CMC ponds. Pearson’s correlation analysis further revealed strong positive correlations between the hydrolytic enzyme activities and nutrient concentrations among the aquaculture ponds, indicating microbial enzyme regulation response to sediment nutrient dynamics. Our study herein reveals that farming practices of fish and crab differently affect bacterial communities and enzymatic activities in pond sediments, suggesting nutrient-driven sediment biological processes in aquaculture ponds for different farming practices.

Pollution Characteristics and Risk Assessment of Heavy Metal Elements in Sediment in the West Lake of Hengshui Lake

21 sampling points were set in the West Lake of Hengshui Lake including 20 fish ponds and 1 natural pond to analyze the contents distribution of heavy metal elements including Cr, Zn, Pb, Cu, Cd, Hg, As, and Sb in sediment. The degree of heavy metal pollution was evaluated by the geoaccumulation index (Igeo) method. The results showed that the concentrations of Cr, Zn, Pb, Cu, Cd, and Hg at in all sampling points of the fish ponds were lower than soil risk screening values of agricultural land in soil environmental quality: risk control standard for soil contamination of agricultural land (trial) (GB 15618‐2018). The concentrations of As at 5 sampling points were higher than soil risk screening values and lower than soil risk control values of agricultural land in GB 15618‐2018. The concentrations of Sb were lower than soil risk screening values of construction land in soil environmental quality: risk control standard for soil contamination of development land (trial) (GB 36600‐2018). The evaluation results of the geoaccumulation index method showed that the pollution degrees of Cd, Pb, and Hg were moderately contaminated in general, the pollution degree of Cu was uncontaminated to moderately contaminated in general, the pollution degrees of Cr and As were uncontaminated to moderately contaminated in some sampling points, and Zn and Sb could be regarded as uncontaminated in sediment of the fish ponds in the West Lake of Hengshui Lake. Otherwise, the average contents of other heavy metal elements in sediment of the fish ponds in the West Lake of Hengshui Lake were higher than the background value of soil in Hebei Province (BVSH) except for Zn and Sb. The average contents of seven heavy metal elements in sediment of the natural pond in the West Lake of Hengshui Lake were lower than BVSH except for Cr. The result can be regarded as no pollution in the natural pond because the values of Igeo were all lower than 0. The heavy metal pollution in the sediment of the West Lake of Hengshui Lake may be due to the introduction of feeding. The water environment of the West Lake of Hengshui Lake can be effectively improved by cleaning up the sediment of fish ponds and “returning fishing to wetland.”

Bacterial content in fish, water, and sediments of different fish ponds in the Patuakhali Science and Technology University (PSTU) campus: a food safety aspect for the consumers in the PSTU

Bacterial content in fish, water, and sediments of different fish ponds in the Patuakhali Science and Technology University (PSTU) campus: a food safety aspect for the consumers in the PSTU

Geochemical speciation of metals (Cu, Pb, Cd) in fishpond sediments in Batan Bay, Aklan, Philippines.

Batan Bay in Aklan, Philippines supports a population largely dependent on coastal fisheries. The development of aquaculture technologies coupled with over-crowded fish pens has negatively affected its natural dynamics and environmental quality. Land-use activities including ports and shipyard further aggravate the problem by contributing to chemical pollution. The present study applied sequential extraction techniques to determine the geochemical speciation of metals in fishpond sediments. Samples were processed and analyzed for Cu, Cd, and Pb using flame atomic absorption spectroscopy. Copper (Cu) showed the highest concentration (10.61-66.81μg/g-dry weight of sediment). Lead (Pb) content ranged from below detection limit to 15.14μg/g, while Cd concentration ranged from below detection limit to 2.50μg/g. Fractionation study showed that the Cu present in the fishpond sediments is mostly non-residual (50.03-73.34%) and significantly associated with the oxidizable fraction (33.89-64.75%). In contrast, the residual fraction served as the dominant host of Pb (33.55-62.68%) in the sediments. Comparison of the results with US EPA and NOAA sediment quality guidelines also revealed that the Batan Bay sediments may be considered generally non-polluted with respect Cu, Pb, and Cd, and not expected to cause adverse effects to aquatic organisms under normal conditions. However, under certain redox conditions, most of the sites may be considered moderately polluted as a result of Cu mobilization from the non-residual fractions of the sediments. Overall, geochemical speciation studies in an important fishery area like Batan Bay will provide valuable insights into the availability of metal contaminants to aquatic organisms under certain environmental conditions.

Avaliação de teor de metais pesados em cultivo de jambu (Acmella oleracea [(L) R. K Jasen]) com sedimento de viveiro de Tambaqui (Colossoma macropomum

A aquicultura tem se destacado nos últimos anos como fonte de proteína animal, porém, um de seus entraves é o descarte indevido de seus efluentes, que além de possuir resíduos orgânicos, apresenta nutrientes essenciais. O reaproveitamento desses rejeitos na agricultura pode ser uma provável saída para sanar tal problema, gerando aporte nutritivo para plantas e mitigando contaminações ao meio ambiente. O estudo objetivou avaliar a viabilidade do uso de sedimento de viveiro de produção de tambaqui para o cultivo de jambu na Região Amazônica. O experimento foi conduzido em casa de vegetação na Universidade Federal Rural da Amazônia utilizando resíduo oriundo de tanques de piscicultura. Foi constituído de cinco tratamentos, variando as concentrações de Terra preta (TP) e Sedimento de viveiro de piscicultura (SP), e acondicionado com 1kg Casca de arroz queimado (CA) para cada concentração. As concentrações foram compostas por Tratamento 1 (100% TP), Tratamento 2 (75% TP + 25% SP), Tratamento 3 (50% TP + 50 % SP), Tratamento 4 (25% TP + 75% SP) e Tratamento 5 (100% SP). O sedimento foi coletado em um viveiro de produção semi-intensivo de tambaqui e as plantas de Jambu foram irrigadas diariamente em vasos de polietileno até 79 dias após germinadas para a realização da colheita. O delineamento experimental foi inteiramente casualizado com 5 tratamentos e 10 repetições, sendo uma planta por repetição ao final do cultivo. Foram obtidos dados de Altura (ALT), Diâmetro de coleto (D), Número de folhas (NF), Clorofila (C), Área foliar (AF), Massa fresca total (MFT), Massa fresca de folha (MFF), Massa fresca de caule (MFC), Massa fresca de flor (MFFL), Massa fresca de raiz (MFR), Massa seca total (MST), Massa seca de folha (MSF), Massa seca de caule (MSC), Massa seca de flor (MSFL) e Massa seca de raiz (MSR). Os dados foram submetidos à análise de variância, sendo as equações escolhidas com base na significância dos coeficientes de regressão, a 5% de probabilidade, utilizando o software Sisvar, versão 5.6. Os tratamentos 2 (75% TP + 25% SP) e 4 (25% TP + 75% SP) foram os que apresentaram os maiores valores para a maioria dos fatores analisados. Quando analisado o comportamento linear da regressão, foi encontrado correlação positiva com as concentrações de sedimento para ALT, NF, AF, MFFL e MSFL, e os demais parâmetros apresentaram comportamento quadrático, tendo faixa ótima sempre próxima aos tratamentos 3 (50% TP + 50 % SP) e 4 (25% TP + 75% SP). A produção do jambu com resíduos de cultivo de peixe é viável haja vista o maior incremento de biomassa nas plantas submetidas a este tipo de substrato.

Improving Productivity in Integrated Fish-Vegetable Farming Systems with Recycled Fish Pond Sediments

The increasing intensification of aquaculture systems requires the development of strategies to reduce their environmental impacts such as pollution caused by the discharge of nutrient rich sediments into local water bodies. Recycling of fish pond sediments (FPS) as fertilizer has been proposed as a possible solution that may also reduce the reliance on synthetic fertilizers. With a case study in the Mekong Delta, Vietnam, we determined suitable mixtures of striped catfish (Pangasianodon hypophthalmus) pond sediment (PPS) and locally sourced organic amendments of rice straw (RS), or common water hyacinth (WH) to fertilize cucumber plants (Cucumis sativus L.) in an integrated cucumber–giant gourami fish (Osphronemus goramy) farming system. Highest nutrient concentrations were found when mixing 30% PPS with 70% RS or WH. When used in combination with chemical fertilizer, it was found that a 25% to 75% reduction in chemical fertilizer application could be achieved, while also increasing cucumber yields, with the highest yields found when RS was used in organic amendments. In combination with the additional income from fish production, integrated farming systems such as that demonstrated in this study, may increase both farm income and production diversity.

Effect of Bio-Enzymatic Preparation on Water Quality in Ponds and on Quantity and Quality of Fishpond Sediments

The aim of this study was to evaluate the ability of a bacterial-enzymatic preparation to affect water quality, particularly the composition and the amount of sediments in ponds. The PTP Plus preparation was applied during the year 2016. For evaluation of the possible effects of the preparation, the water and sediment was compared in the growing seasons 2016 and 2017. When monitoring the sediment loss, a difference ranging from 72 to 86 mm was measured. There was an increase in the level of conductivity, alongside with an increase in the amount of calcium and chlorides in the water. In the case of the sediment, there was an increase in the amount of organic substances in the aqueous leachate and a decrease in the amount of available and total calcium. Changes of other monitored parameters were not so clear. The significant changes in water and sediment quality in the individual years of monitoring were probably more influenced by climatic conditions and significant growth of macrophytes in 2017 than by the application of the product. The expected reduction of the share of organic matter in the sediments after the application of the product has not been confirmed.

Potential of Fish Pond Sediments Composts as Organic Fertilizers

Increased fish pond production is associated with the generation of various waste including fish pond sediments. Fish pond sediments could be a valuable source of nutrients for growing plants, however they require further processing in order to be applied to soil. Composting is considered one of the methods for processing fish pond sediments. The aim of this work was to investigate the potential of organic fish pond sediments to be managed through laboratory composting with selected waste materials and evaluate the fertilizing potential of the obtained compost. The scope included: (1) analysis of organic fish pond sediments, (2) laboratory composting of organic fish pond sediments with wheat straw and green grass, (3) analysis of the obtained composts, (4) preparation of growing media with selected additives, (5) analysis of the properties of the prepared growing media and (6) analysis of the effect of the investigated growing media on the growth of Phaseolus vulgaris L. in pot experiments. The addition of cardboard waste and woodchips derived biochar to the obtained compost improved significantly the growth of the roots of Cardamine L. Also, the content of carbon and nitrogen in the compost mixtures increased. The addition of M1 (compost from organic fish pond sediments and 1% of biochar) to the soil had a significant impact on the growth of white beans.Graphic

Study on the use of sludge farming of catfish as organic fertilizer and evaluate its effectiveness in agriculture

The purpose of this study is to reuse fishpond sediment to produce organic fertilizer for planting maize. The sludge was mixed with rice husk and Composted under aerobic conditions. The effectiveness of Compost on planting maizes was assessed by adding to maizes with and without combination chemical fertilizers as different dosages as recommendations. The amounts of Compost adding for maizes were 10 and 20 tons/ha. Maize growth, characteristics of corn, and soil physical and chemical parameters such as bulk density, soil aggregate stability, the volume of moisture, and useful moisture of soil were measured and evaluated. The results showed that the quality of organic fertilizer produced from waste sludge met Vietnamese standard (QCVN:2018/BNNPTNT) for adding to crops. Applying organic fertilizer with the quantity of 20 tons/ha to combine with the recommendation of inorganic fertilizer amount for planting maizes increased the yield. Moreover, 20 ton/ha of organic fertilizer coupling with 50% of chemical fertilizer amount as a recommendation for planting maize also enhanced the yield to compare with the control (only using inorganic fertilizer as a recommendation). The maize yield of applying 20 tons/ha of organic fertilizer was higher than the maize yield of 10 tons/ha of organic fertilizer. Using organic fertilizer produced by fishpond sediment did improve not only the soil quality but also protected the canals and increased household income.

Assessment of fish pond sediments for growth, yield and nutritional quality of Indian spinach (Basella alba L.)

Integrated farming system is a very effective tool for improving rural economy. Our present study was carried out in different pond dykes of Dumuria upazila of Khulna district, Bangladesh to investigate the effect of different fish pond sediments on growth, yield and subsequently analyze the nutritional quality of Indian spinach. The experiment consisted of two factors viz., pond types (P) (three different ponds growing different fish species: P1 = prawn and carp, P2 = prawn and mola, and P3=prawn, mola and carp) and each pond was cultivated with different fish species with different population densities); and pond sediments (M) (three levels: M1 = pond dyke soil, M2 =50% pond mud and 50% pond dyke soil, and M3 =100% pond mud). Physical and chemical properties of three ponds dyke soil as well as sediments were analyzed. Parameters studied on Indian spinach were growth, yield and nutritional qualities. Pond sediments were better quality due to well decomposition and microbial activity of sediments compared to dyke soil of ponds. Organic matter of pond sediment was 2.79 (P3) and EC was 790 (µc/cm). Plant height was varied from 10 to 19% due to the ponds type and sediment effects. Mostly, the plant growth was found better under the supplement of 100% pond sediments compared to dyke soil (M1) and mixed soil (M2). The highest yield was found in P3M3 and it was varied from 20 to 25%. Minerals like Ca (%), P (%), and S (mg/100g) were found statistically significantly higher in P2M3 compared to other treatments combinations. Nutrition like Vit A and Vit C were the highest (81.33 µg/100 g and 106.14 mg/100 g, respectively) found significantly higher in P2M3. Therefore, the pond mud (50% and 100%) can be used to increase the yield and nutrient uptake by the crop which can facilitate to reduce eutrophication and fertilizer for the better environment.

Fish pond sediment from aquaculture production – current practices and the potential for nutrient recovery**: a Review

Fish pond sediment from aquaculture production – current practices and the potential for nutrient recovery**: a Review

Release of toxic elements in fishpond sediments under dynamic redox conditions: Assessing the potential environmental risk for a safe management of fisheries systems and degraded waterlogged sediments

Waterlogged soils and sediments contaminated with potentially toxic elements (PTEs) constitute a complicated case of degraded areas; their management requires understanding of the dynamic redox-driven PTE mobilization. Such studies about PTE redox-induced dynamics in fishpond sediments are still scarce, but of great importance concerning environmental and human health risk. We studied the redox potential (EH)-induced impacts on the solubility of As, Co, Cu, Mo, Ni, Se, V, and Zn in the sediments of a fish farm in the Nile Delta, Egypt, using an automated apparatus of biogeochemical microcosm. We assessed the fate of elements as affected by the EH-induced changes in pH, Fe, Mn, SO42−, Cl−, and the dissolved aliphatic (DOC) and aromatic (DAC) organic carbon. Sediment redox ranged from −480 mV to +264 mV. Flooding the sediments caused a significant decrease in pH from 8.2 to 5.7. Dissolved concentrations of As, Co, Ni, Se, and Zn, as well as DOC, Fe, and Mn increased under the reducing acidic conditions. The release of As, Co, Ni, Se, and Zn could be attributed to the decrease of EH and the subsequent decrease of pH, as well as to the increase of DOC, and/or the dissolution of Fe–Mn oxides caused by redox reactions. Dissolved concentrations of Cu, Mo, and V increased under oxic conditions and were significantly positive correlated with EH, pH, DAC, and SO42−. This enhancement might be caused by the EH-dependent increase of pH under oxic conditions (particularly for Mo and V), which also led to DAC increase. Sulfide oxidation and the release of the associated elements may have also had a contribution, particularly in the release of Cu. Therefore, the release dynamics of dissolved Cu, Mo, and V in the sediments were controlled, to a certain extent, by the changes of EH/pH, DAC, and sulfur chemistry. We conclude that the biogeochemical differences in the behaviour of the studied elements under variable redox regimes substantially affected the fishponds via possible enhancement of PTE mobilization. Our work shows that the potential environmental risks related to PTE mobilization and fish food security should be taken into consideration for the management of degraded aquaculture systems and waterlogged soils and sediments.

Application of fishpond sediment and water to increase the efficiency of phosphorus fertilization in land integrating agriculture and fishery

The utilization of water from Mount Salak by farmers in addition to agriculture activities is also for fishponds that are widely spread among agricultural lands. The phosphate from fishpond sediment and water flowing to the river was supposed contributing to the enriched phosphate in the Jakarta Bay. The use of fishpond sediment and water in agricultural land was expected to decrease the load of phosphate to the river and increase the efficiency of phosphorus (P) fertilization by decreasing P sorption and increasing the release of P. The fishpond sediment with the rates of 0, 2.5%, 5.0%, 7.5% and 10% were combined with fishpond water or distilled water for watering. They were incubated for one month. The experiment was set up in Completely Randomized Design with three replicates. The results showed that fishpond sediment treatments decreased P bonding energies of P sorption and after P desorption and also the rate constant of P sorption. The best treatment in this experiment was the application of 10% of fishpond sediment watered by fishpond water for those determined parameters. The results suggested that application of fishpond sediment and water increased the efficiency of P fertilization in land integrating agriculture and fishery.

Exploration of the antibiotic resistome in a wastewater treatment plant by a nine-year longitudinal metagenomic study

The spread of antibiotic resistance genes (ARGs) is a growing global problem. Activated sludge (AS) in wastewater treatment plants (WWTPs) has been proposed as a hotspot for ARGs. However, few studies have been conducted to uncover the temporal dynamics of the resistome of AS in WWTPs by long-term longitudinal sampling. In this study, we quantified ARGs and identified their host microbiome in a Hong Kong WWTP in 97 monthly AS samples spanning 9 years. Throughout this analysis, we demonstrated that both the abundance and structures of the resistome changed significantly every two to three years, implying that there was a successive selection of resistomes in the AS system over the study period. The detection of genes of antibiotic-resistant pathogens that are emerging major threats to public health in the AS samples, including mcr, CRE (carbapenem-resistant Enterobacteriaceae) and MRSA (methicillin-resistant Staphylococcus aureus)-related genes, highlight the role of WWTPs as reservoirs of ARGs. In addition, the core resistome (abundant and persistent genes) in AS were found to overlap with those in other ecosystems such as urban sewage, livestock feces, and fishpond sediments, revealing the broad dissemination of ARGs in WWTPs and other environments. Annual variation of resistomes were explained via structural equation modeling (SEM), which deciphered the structural linkages of determining factors such as the operational parameters, microbial community composition and horizontal gene transfer (HGT). Specifically, potentially relevant antibiotic resistance bacteria (ARBs) were explored and discussed based on assembly-based analyses and network correlations. Moreover, consistent with the clear relationship between resistomes and mobile genetic elements (MGEs), it was found that there was a relatively high potential for gene exchange in AS in comparison with soil genomes, which could be explained by the engineering features of WWTPs. Based on these findings, longitudinal monitoring of WWTPs is warranted for risk assessment to reveal emerging ARGs, resistome evolution, correlations with ARBs, and the potential for spread in downstream environments and concomitant exposure risks for humans.

Bioaccumulation and health risk assessment of trace metals in fish from freshwater polyculture ponds in Chengdu, China.

The freshwater polyculture pond culturing occupied an important position in the aquaculture industry. Accumulation of trace metals was investigated in water, sediments, and fish (Carassius auratus, Cyprinus carpio, Ctenopharyngodon idellus) from typical polyculture ponds in Chengdu, China. The results showed most of the pond water in Chengdu were safe for fish cultivation. The Cd and Cr concentrations in sediment samples from sites S3, S4, and S9 which were near the industrial park and road with a high traffic volume were higher than those of the other sites. Cu, Cr, Fe, Zn, Mn, Ni, and Pb in sediments were unpolluted, while Cd was unpolluted to moderately polluted due to anthropogenic activities. Cu, Cd, and Pb in fish pond sediment of Chengdu had higher potential mobility under normal environmental circumstances. The trace metal concentrations in liver of three fish species were all higher than those in muscle tissues. The order of bioaccumulation factor (BAF) values for trace metals was Cr > Cu > Pb > Zn > Cd > Ni > 20. The concentrations of Cu, Cd, Pb, Zn, and Cr in the muscle of three fish species were all below the local and international maximum permissible levels. The target hazard quotient (THQ) and hazard index (HI) of trace metals in aquaculture fish ponds in Chengdu were lower than 1, which indicated that the consumption of grass, crucian, and common carp cultivated in the aquaculture ponds of Chengdu pose no health risk to the residents.

The Effects of Fish Pond Sediments and Cow Dung on the Early Growth of Afrormosia elata Harms Seedlings

More often than not, the emphasis is laid on the essence of employing organic manures for raising plant seedlings and even in improving the nutrient status of their growth media for higher productivity. Afrormosia elata has numerous medicinal uses but not very much available. Thus, the study on the effects of fish pond sediments (FPS) and decomposed cow dung (DCD) on the early growth of A. elata seedlings was carried out at the nursery ‘A’ of the Federal College of Forestry, Ibadan, Nigeria. A. elata seeds were sown in a finely perforated sieve (filled with washed river sand) and seedlings were pricked – out 2 weeks after seedling emergence into polythene pots with varying levels of FPS and DCD. The experimental design was Completely Randomized Design (CRD) consisting of nine treatments and eight replicates. Treatments include; T1(2 kg of FPS + 2 kg of topsoil); T2 (2 kg of DCD + 2 kg of topsoil); T3 (1.5 kg of FPS + 2 kg of topsoil); T4 (1.5 kg of DCD + 2 kg of topsoil); T5 (1 kg of FPS + 2 kg of topsoil); T6 (1 kg of DCD + 2 kg of topsoil); T7 (500 g of FPS + 2 kg of topsoil); T8 (500 g of DCD + 2 kg topsoil); and 2 kg of topsoil without any treatment served as control). Morphological parameters such as seedling height, collar diameter and leaf count as well as leaf biomass were assessed and the data collected were subjected to Analysis of Variance (ANOVA). The result showed that T3 (1.5 kg FPS + 2 Kg TS) had the best performance in height, leaf area and leaf biomass with mean values of 11.02 cm, 21.65 cm2 and 1.16 g respectively. Though, there were no significant differences amongst the growth parameters assessed for this study. But T3 (1.5 kg FPS + 2 Kg TS) could be employed in raising the seedlings of this plant for faster growth rate.

Evaluation of the bioremediation potential of mud polychaete Marphysa sp. in aquaculture pond sediments.

Organic enrichment from aquaculture could alter the chemical composition of the fishpond bottom by increasing the levels of organic matter (OM), sulfur (S), iron (Fe), and lower pH of the sediment. Polychaetes can contribute to the nutrient cycling and remediation of polluted sediment. A laboratory experiment was conducted to test the remediation potential of small and large mud polychaete Marphysa sp. introduced to two types of fishpond sediment. Initially, Sediment A had lower OM, S, Fe, and higher pH than Sediment B. After 30 days, in Sediment B, large polychaetes significantly decreased the OM level (27%) while both small and large polychaetes promoted significant decreases of S (71%) and Fe (70-73%) in both sediment types. The increase of sediment pH was promoted by the presence of polychaetes (0.53-0.69) although pH level in small polychaete was not significantly different with the no polychaete treatment. Regardless of polychaete treatment, the pH level of Sediment B (1.04 ± 0.10) was significantly improved than that of Sediment A (0.17 ± 0.02). In both sediments, large polychaetes (95%) had better survival rates than small polychaetes (73%). These findings reveal that large Marphysa sp. can significantly improve sediment quality by decreasing the levels of OM, S, and Fe and improve pH level to a more basic form without compromising its survival. Large polychaetes are recommended to be used as bioremediators of organically enriched aquaculture pond sediment.

Pengaruh Pemberian Pelet dari Lumpur Kolam Ikan dan Kotoran Kambing pada Pertumbuhan dan Produksi Jagung Manis

A mixture of fishpond sediment and goat manure can be used to increase the growth and yield of sweet corn. This research aimed to determine the effect of pellet from the combination of fishpond sediment and goat manure with a ratio 1:1 on nutrient (N, P, and K) and yield on sweet corn. The land used was Ultisol Dramaga which was located in Cikabayan Experimental Farm, Bogor Agricultural University. The study was conducted in a greenhouse with a Completely Randomized Design (CRD) of one factor with eleven treatments: without treatment (control); standard fertilization (Urea 0.43 ton ha -1 , SP-36 0.41 ton ha -1 , and KCl 0.25 ton ha -1 ); three doses of pellet (20 ton ha -1 , 30 ton ha -1 , and 40 ton ha -1 ); three doses of fishpond sediments (10 ton ha -1 , 15 ton ha -1 , and 20 ton ha -1 ); three doses of goat manure (10 ton ha -1 , 15 ton ha -1 , and 20 ton ha -1 ). The result showed that giving 40 ton ha -1 pellet had a significant effect on the increasing pH, ammonium, and the availability of K in Ultisol and nutrient content of P, K, and the weight of dry-grain sweet corn.

Cadmium and Lead Hazardous Impact Assessment of Pond Fish Species.

The current study aims to assess the concentration of cadmium (Cd) and lead (Pb) in five tissues of Cirrhinus mrigala, Labeo rohita, and Catla catla collected from fishponds of Jamshoro and Larkana, Sindh, Pakistan. Meanwhile, the levels of Cd and Pb in feeding materials, water, and sediments of fishponds of both areas were also studied. The daily intake and hazardous impact assessment of Cd and Pb by muscles of three fish species of fishponds of both areas were estimated. The concentration of Cd in tissues of C. mrigala and C. catla of Larkana were higher than that in tissues of same fish species of Jamshoro whilst Pb contents in tissues of fishes of Jamshoro were high (p > 0.05). The feeding materials of fishponds of Larkana were enriched with Cd whilst Pb was high in feeding material of fishponds of Jamshoro. The estimated bioaccumulation factor, average daily intake, and hazardous quotient of Pb were high as compared to Cd in all studied fish species of fishponds of Larkana and Jamshoro. The hazardous quotient of Pb indicated that the local population of both areas might have a potential toxic risk. Graphical abstract ᅟ.

Isolation and characterization of AHL-degrading bacteria from fish and pond sediment

Quorum sensing (QS) disruption is considered as a potential alternative strategy to combat bacterial diseases in aquaculture. In this study, we isolated and identified bacteria degrading QS molecules from pond sediment and fish intestine. A total of 132 strains were obtained in the enrichment culture, of which two strains were identified as Enterobacter sp. f003 and Staphylococcus sp. sw120, being isolated from the fish intestine and pond sediment, respectively. We found that strains f003 and sw120 could degrade acyl-homoserine lactones (AHLs) and cause no hemolysis of sheep red blood cells. The AHL lactonase ( aiiA ) homologous gene in the two strains was detected in PCR amplification and the high-degrading activity to N-hexanoyl-L-homoserine lactone (C6-HSL) and AHLs secreted from pathogenic Aeromonas hydrophila was assessed. Meanwhile, the artificial infection of cyprinid C arassius auratus gibelio with intraperitoneal injection showed that the two strains were avirulent. Therefore, the obtained indigenous bacteria are candidate probiotics against pathogenic A. hydrophila in aquaculture.