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Urbanisation results in the loss and alteration of natural wetlands and ponds. However, garden ponds in cities and towns can potentially act as rich reservoirs of aquatic biodiversity and stepping stones for dispersal. Homeowners with a range of different motivations, including biodiversity values, install garden ponds. Here, our main aim was to study whether the design and management choices of garden pond owners depended on the location of ponds (capital city vs. countryside), when ponds were installed (pond age), or whether fish were introduced. We surveyed 834 garden pond owners across Hungary using a citizen science questionnaire, asking questions on pond size, location, construction date and materials, vegetation structure, introduction of fish and management practices. From 753 validated responses, we found that the introduction of fish into ponds and high urbanisation were strongly associated with local features and management practices, especially large ponds with a water circulation feature, irrespective of pond age. A typical garden pond in Hungary is ~ 20 m2, < 10 years old, made of rubber lining, contains fish, aquatic vegetation and circulating water, and is actively managed. There was a spatial separation of ponds based on local features between ponds in the capital city (Budapest) and elsewhere. These findings suggest that garden pond owners in the city were more likely to make different choices in pond design and management compared to owners in regional areas. Our results also suggest that pond owners may primarily select management practices to improve habitat quality for ornamental fish. Our findings have important implications for maintaining aquatic biodiversity in urban areas, where garden ponds may be the only aquatic habitat available. [ABSTRACT FROM AUTHOR]

Studies have emphasized that the presence of heavy metals in freshwater fish represents a global public health issue. Nigeria, being a developing nation with less emphasis on the quality of seafood consumed by the residents, ranks this study very vital. The policy implication of this study is the advancement of a healthy population in contemporary Nigeria. Hence, this study assessed heavy metal concentration in two fish species, Clarias gariepinus (Catfish) and Oreochromis niloticus (Nile Tilapia), in the Anambra River. The sample included twenty fishes, of which eighteen were collected from the three sampling locations (the fish ports of Anambra River), namely Otu-nsugbe, Otuocha, and Ikemivite) while two control samples were collected from a pond about 200 m away from the river. The levels of heavy metals were determined using Varian AA 240 atomic absorption spectrophotometer (AAS). The results showed that the concentrations of heavy metals (cadmium and arsenic) in the sampled fishes from Anambra River exceeded the joint World Health Organization and Food and Agriculture Organization (FAO/WHO) standard for fish and fish product consumption, while the concentration of chromium, mercury, and lead are within the permissible limit. The study also showed the distribution of the heavy metals in the fish organ varies among fish species. Heavy metals occur higher in Clarias garepinus than in Oreochromis niloticus, while tissue preference for heavy metal accumulation is in the order of gill > liver > muscle. It was recorded from this study that the heavy metal concentration in the fish from the pond is generally higher than the fish from the river for some metals. The high level of heavy metals in the sampled fish was attributed to heavy metals contamination of the river as a result of various anthropogenic activities such as mining, burning of fossil fuel and emission from the exhaust of boats/vehicles, overuse of fertilizers and pesticides, discharge of effluent, sewage, and hospital waste. This study concluded that long-term consumption of fish from the river may pose health risks to the consumers due to the possible bioaccumulation of heavy metals, especially cadmium and arsenic. It was recommended that continuous monitoring of heavy metal levels in the fish and water, public awareness, and appropriate legislative provisions should be put in place to ensure that harvested fish and fish products may be safe for human consumption. [ABSTRACT FROM AUTHOR]

The importance of fish farming can never be over emphasized because it's a major provider of dietary protein, source of income and employment for the growing populations in Nigeria. Similarly, the importance of the bacteriological evaluation of fish pond water can never be over emphasized as it is a major indicator of the suitability and sanitary condition of the aquaculture pond and the fish in particular. This study evaluated the bacteriological profile of different fish pond water located within Owerri metropolis. A total of 10 fish pond waste water samples were collected and analyzed using different selective microbiological media and isolates identified using gram staining and biochemical reactions. Result shows that the total heterotrophic bacteria count ranged from 6.4x10³ CFU/mL - 7.5x107 CFU/mL, total coliform count ranged from 2.1x104 CFU/mL - 5.6x107 CFU/mL, total vibrio count ranged from 2.7x10³ CFU/mL - 5.9x105 CFU/mL while the Salmonella / Shigella count ranged from 1.9x105 CFU/mL - 5.9x105 CFU/mL. A total of nine bacterial isolates were identified which includes Staphylococcus spp, Escherichia spp, Vibrio spp, Salmonella spp, Enterobacter spp, Shiglla spp and Klebsiela spp. The result revealed a high bacterial load in the fish pond water and therefore recommends constant water change to prevent the possible buildup of potential pathogenic bacteria in fish and introduction of these organisms into the environment. [ABSTRACT FROM AUTHOR]

The article describes epizootology, diagnosis of lerneosis of fish that are fed in artificial reservoirs, clinical signs observed in them, as well as an analysis of scientific sources on methods of treatment and prevention. With lerneosis of fish, cases of blood clots, deep wounds, raising and loss of scales are observed on the body of fish, which leads, first of all, to loss of marketability, growth lag behind development, decreased immunity in Pisces, leading to the fact that it becomes susceptible to various infectious diseases. Lerns in the body of fish penetrate through the gills into the internal organs, causing damage to the liver and intestines, which also leads to the development of hepatitis B of the liver. During pathological studies, blood clots in the liver and intestines and necrosis of the intestinal mucosa were observed in fish with lerneosis. Fish affected by lernaea are carriers of the disease the following year, and the larval stage of lernaea is the source of the disease. Infection of fish with Lernea in fish ponds is generally much higher in improperly constructed, undrained, unsanitary ponds in winter, where their numbers can reach dozens per body of each fish. [ABSTRACT FROM AUTHOR]

Aquaculture pond sludge and fish waste are key environmental pollutants in the aquaculture and fish processing sectors, and they must be managed to reduce their negative environmental impacts. Aquaculture pond sludge and fish waste were used as bedding materials in this study to make Eisenia fetida vermiwash. The vermiwash was prepared using three substrate combinations: cow dung and Gliricidia leaves (control), cow dung and aquaculture sludge (ASV), and cow dung and fish waste (FWV) at a 2: 1 ratio. E. fetida (35-40 worms·kg-1 of bedding material) were introduced to each vermiwash preparation unit, and vermiwash samples were collected weekly for four weeks after one month of worm introduction. Chemical oxygen demand (COD), pH, conductivity, potassium (K), total nitrogen (TN), and orthophosphate of vermiwash samples were measured. ASV contained significantly higher total nitrogen and less potassium than FWV and the control (p<0.05). While orthophosphate, pH, and COD among experimental vermiwash were not significantly different (p>0.05), the conductivity was significantly higher in FWV. Except for the low K and high TN levels, ASV was chemically comparable with the control vermiwash. Phaseolus vulgaris seeds exposed to ASV had a comparatively higher germination (63%) than those exposed to control (47%) and FWV (37%). The earthworm survival decreased to 9% in the FWV unit and increased by 49% and 33% in the control and ASV units, respectively. The findings demonstrated the feasibility of producing vermiwash from aquaculture sludge for integrated aquaculture and agriculture. [ABSTRACT FROM AUTHOR]

A study of the fish caught in the reservoirs of the Khadzhibey estuary (Odesa region) was conducted in order to determine its quality and safety according to microbiological indicators. No pathogenic or conditionally pathogenic microorganisms were found in all the fish samples studied – mirror carp (Cyprinus carpio) and round goby (Neogobius melanostomus). During the study of physico-chemical indicators of water quality and safety of the estuary, water samples were taken for the content of pesticides, insecticides and heavy metals. The content of cadmium, copper, lead and mercury does not exceed the permissible level for fish farms, zinc exceeds the maximum permissible concentration by 2.3 – 3.0 % (depending on the period of the year). The insecticide dichlorodiphenyltrichloromethylmethane was found in the water, the content of which exceeds the maximum allowable concentration for sea fishing ponds by 18 %, and the pesticide betahexochlorocyclohexane – by 5.2 %. It has been studied and established that the fish caught in the estuary, according to its microbiological and physicochemical indicators, is safe, does not pose a threat to the health of people and animals, and is suitable for further use and consumption. [ABSTRACT FROM AUTHOR]

Ornamental fish are becoming increasingly popular, but the lack of knowledge regarding their various diseases is a major challenge. Skin diseases commonly found in freshwater fish include black spot disease (BSD), which is characterized by melanin deposits around the metacercariae of some trematode species. Since BSD remains poorly understood, this study describes an outbreak of BSD in Etroplus maculatus raised in outdoor ponds at a Brazilian fish farm. Metacercariae samples were collected, examined, and subjected to molecular phylogenetic analysis. The parasites were conspecific to an unnamed species, Crassiphiala lineage 5, recently found in Brazilian birds (Megaceryle torquata). Sequences obtained for longifurcate cercariae of the planorbid snail Biomphalaria straminea from the same region were identical to our metacercariae of Crassiphiala sp. These results suggest that Biompahalaria snails are likely an intermediate host of this parasite on farms where E. maculatus was found to be infected. We provide the first molecular evidence that Crassiphiala are the causative agents of BSD in fish from Brazil. Combatting snails and preventing access of fish-eating birds to outdoor ponds are strategies to control this disease in ornamental fish farms. [ABSTRACT FROM AUTHOR]

The assessment of the current distribution and concentrations of As, Pb, Hg, Cd, and Cr in farmed catfish and tilapia, fish feed, and pond sediment in Tanzania is important in order to establish the potential dietary exposure to heavy metals from aquaculture sources. Thirteen fish ponds were selected from each of the 10 sites (villages) studied in Arusha and Morogoro regions. Representative samples collected were analysed using polarised energy-dispersive x-ray fluorescence (PED-XRF) spectrometer. Human health risk from fish consumption was established by calculating the estimated daily intakes (EDI), target hazard quotients (THQ), total hazard indices (HI), and carcinogenic risk (CR) of the heavy metals. Arusha had the highest concentrations (dry weight) of As (2.49–4.75 mg/kg) in the fish feed. Morogoro had the highest concentrations of Hg (1.65–2.69 mg/kg), Pb (4.59–5.64 mg/kg), and Cd (1.99–3.97 mg/kg) for sediment, fish feed, and fish muscles, respectively. Cr was the most accumulated heavy metal in the fish muscles sampled in Arusha (4.61–9.50 mg/kg) and Morogoro (2.53–5.57 mg/kg). Concentrations and EDI calculated based on mean fish consumption of 22.1 g per person per day by a 60 kg Tanzanian adult found heavy metal intakes were below the recommended daily dietary allowance (RDA) while THQ values were lower than 1, indicating no health risk related to consumption of the fish. The estimated HI was greater than 1, suggesting a potential significant non-carcinogenic health risk. The CR values were below 10−4, indicating no carcinogenic health risk in humans from fish consumption. This study recommends continued surveillance given potential bioaccumulation of these heavy metals in fish. [ABSTRACT FROM AUTHOR]

The aim of the current study is to compare total lipid profile of Cyprinus carpio reared in earthen ponds and wild fish (river). A total of 80 fish samples were collected from these locations for the period from November-December 2020 and divided into three weight groups ( W1, less than 500 g ;W2, 500-1000g and W3, more than 1000g). Results of present study showed that the total cholesterol content ranged between 17.69-21.63mg\100g in W3 and W1 respectively in river fish, while in pond fish ranged between 22.08-23.59mg\g in W2 and W3 respectively. High density lipoprotein in river fish ranged between 5.84-12.21mg\g in W3 and W1 respectively, in pond fish ranged between 11.18-12.92mg\g in W2 and W1. Low density lipoprotein in river fish ranged between 0.908-1.215 mg\g in W3 and W2, in pond fish ranged between 1.266-1.588 mg\g in W2 and W3 respectively and finally triglycerides in river fish ranged between 53.25-59.69 mg\g in W3 and W1.In pond fish ranged between 60.57-65.98 mg\g in W2 and W3 respectively. Results of statistical analysis of lipid profile showed a significant difference P≤0.05 of Cholesterol, HDL,LDL and Triglycerides in W3 between ponds and river fish, but no significant difference P>0.05 in W1 and W2 of Cholesterol, HDL,LDL and Triglycerides between ponds and river fish. [ABSTRACT FROM AUTHOR]

To enhance productivity, aquaculture is intensifying, with high-density fish ponds and increased feed input, contributing to nutrient load and eutrophication. Climate change further exacerbates cyanobacterial blooms and cyanotoxin production that affect aquatic organisms and consumers. A review was conducted to outline this issue from its inception - eutrophication, cyanobacterial blooms, their harmful metabolites and consequential effects (health and economic) in aquacultures. The strength of evidence regarding the relationship between cyanobacteria/cyanotoxins and potential consequences in freshwater aquacultures (fish production) globally were assessed as well, while identifying knowledge gaps and suggesting future research directions. With that aim several online databases were searched through June 2023 (from 2000), and accessible publications conducted in aquacultures with organisms for human consumption, reflecting cyanotoxin exposure, were selected. Data on cyanobacteria/cyanotoxins in aquacultures and its products worldwide were extracted and analyzed. Selected 63 papers from 22 countries were conducted in Asia (48%), Africa (22%), America (22%) and Europe (8%). Microcystis aeruginosa was most frequent, among over 150 cyanobacterial species. Cyanobacterial metabolites (mostly microcystins) were found in aquaculture water and fish from 18 countries (42 and 33 papers respectively). The most affected were small and shallow fish ponds, and omnivorous or carnivorous fish species. Cyanotoxins were detected in various fish organs, including muscles, with levels exceeding the tolerable daily intake in 60% of the studies. The majority of research was done in developing countries, employing less precise detection methods, making the obtained values estimates. To assess the risk of human exposure, the precise levels of all cyanotoxins, not just microcystins are needed, including monitoring their fate in aquatic food chains and during food processing. Epidemiological research on health consequences, setting guideline values, and continuous monitoring are necessary as well. Further efforts should focus on methods for elimination, prevention, and education. [Display omitted] • 63 publications from 22 countries are reviewed. • The global "south" tropical zones burdened with increased dependence and climatic factors conducive for blooms. • The most affected are small and shallow fish ponds, omnivorous or carnivorous fish. • Cyanotoxin levels exceeding the tolerable daily intake in 60% of the studies. • Impossible to compare values due to imprecision and lack of validated testing. [ABSTRACT FROM AUTHOR]

The research aimed on detecting the diversity of yeasts and molds in total of 160 common carp (Cyprinus carpio) fishes and clearing the correlation of their occurrence with some parameters of culturing water for (3) fish ponds in Mosul City. Fish and water samples were collected during period January 2019 to March 2020. The colonies of fungi isolated were observed on agar plates in different colors. After priming, the slides were stained with Lactophenol Cotton Blue (LPCB). One hundred twelve fungal isolate were obtained with total isolation rate (70%), including Seven fungal species at a percentage of Aspergillus (33%), Penicillium (25.6%), Alternaria (16.6%), Blastomyces (7.1 %), Rhizopus (5.3%), Saprolegnia (2.6%) and Candida spp. (9.8%). The analyzed parameters of water included: NO2, NO3, GH, KH, PH, CL2, CO2 and NH4, There was a clear relationship between the density and diversity of the pathogenic fungi with similar misalignment of these parameters from desirable values of, it has been found that pond (3) was most common in terms of isolating pathogenic fungi (include species of Aspergillus, Penicillium, Alterneria, Blastomyces, Saprolegnia and Candida spp.) and infected fish, hence it contains water that is not balanced in general relating with proportion for the mentioned parameters, while the parameters (GH and NH4) were the most effectible on the isolation of fungi with statistical significance (P≤0.05). Periodically checking out of the important parameters of culturing water is necessary because of it is effect on the intensity of many pathogenic fungi isolated threatening fish and consumer health. [ABSTRACT FROM AUTHOR]

Aquaculture production continues to grow in West Bengal, where on average people consume 8.2 kg capita−1 of fish each year, and an extensive mosaic of aquaculture ponds has developed along the River Hugli as clay pits are repurposed. The adjacent brickworks and industry (especially tanneries) are a source of environmental pollution, with potential for bioaccumulation of potentially harmful elements (PHEs) in fish farmed in these ponds. Fish from aquaculture present an opportunity to meet food sufficiency in West Bengal; however, an investigation to assess their effectiveness for micronutrient supply balanced against food safety is required. Five ponds close to industrial brick manufacture (urban) and three from rural areas were assessed for the degree of pollution within their pond sediments and waters. Fish were also sampled from each location including a subset from the market in Kolkata to determine the concentrations of PHEs in their fish muscle tissue. Dietary intake and PHE loading were calculated for four fish species to evaluate their nutrient content with respect to recommended daily intakes for adults, e.g. calcium (Ca), potassium (K), magnesium (Mg), iron (Fe), zinc (Zn) and selenium (Se), and to establish whether the provisional maximum tolerable intakes (PMTIs) are exceeded for PHEs, e.g. aluminium (Al), arsenic (As), mercury (Hg), chromium (Cr), tin (Sn), copper (Cu) and lead (Pb). Preliminary results suggest that aquaculture is making an important contribution to nutrition, with fish being a good source of Se. However, in contrast to small wild-caught fish, aquaculture fish in the present study were poor sources of Fe, Ca and Zn. The fish also made substantial contributions (> 10%) to the PMTI of Hg and As. Therefore, there is an urgent need for ongoing monitoring and an expanded sampling programme, as well as research into approaches which might improve the nutritional quality of the farmed fish. [ABSTRACT FROM AUTHOR]

Unique data is reported on the transfer of 129I iodine from freshwaters to fish as well as the internal distribution within fish from the Fukushima and Chernobyl exclusion zones (ChEZ). Samples of water, sediments and fish were collected in the contaminated ponds Inkyozaka and Suzuuchi, and in the less contaminated Abukuma river in Fukushima, as well as in the contaminated Glubokoye lake and in the less contaminated Starukha lake in ChEZ. In water, 129I was mainly present as low molecular mass (LMM) and negatively charged species, while a minor fraction was associated with colloidal fraction, most probably organic material in water. The sediment-water 129I apparent distribution coefficients, Kd, ranged from 225 to 329 L/kg, equal that of stable iodine, but did not correlate with 129I/127I ratio or 129I/137Cs ratio as the environmental distribution of radioactive iodine was different from that of stable iodine and radioactive cesium. Concentration ratios (CR) of 129I in muscle of freshwater fish ranged from 85 to 544 across waterbodies with limited water exchange, similar in Fukushima and Chernobyl, but varied with respect to fish species. Thus, this is the first results on the transfer of 129I to freshwater fish, showing that the CR for freshwater fish is higher than CR reported for marine fish. Concentrations of 129I in fish muscle were, however, lower than in the intestinal content, indicating the influence of more contaminated dietary ingredients probably of terrestrial origin based due to δ13C signal on as well as of biodilution. The present results highlighted also that the radiation dose in fish was highly inhomogeneously distributed. Based on the present 129I/127I atomic ratio of 10−5 in the most contaminated fish in the ponds in Fukushima and Glubokoye lake in Chernobyl, however, a radiation dose of 10 μSv/y would not pose any harm to the fish population. [Display omitted] • Transfer of 129I to freshwater fish is for first time documented. • Freshwater fish concentration ratios is 85–588 dry weight and higher than reported for marine fish. • Dietary transfer of 129I to freshwater fish seems significant. • 129I apparent distribution coefficients (Kd) ranged from 225 to 329 L/kg in closed waterbodies. • No observed difference in transfer of 129I in Fukushima and Chernobyl freshwater bodies. [ABSTRACT FROM AUTHOR]

Aims: This investigation was undertaken to study the prevalence, enterotoxin gene profile and molecular epidemiology of Aeromonads from various sources of water (182) and fish (173). Methods and Results: A total of 116 Aeromonas sp. were isolated, of which 48 (26·37%) were from water and 68 (34·62%) were from fish samples collected from retail markets and fish farms. The Aeromonads were recovered from all types of water sources viz. drinking water (13%), surface waters (26%) and fish ponds (69%). The most prevalent species recovered from drinking water was A. hydrophila, from fish ponds it was A. caviae, from surface water sources A. hydrophila and A. caviae were recovered more frequently, and A. hydrophila and A. veronii bv. sobria were isolated predominantly from gills of fish samples. On multiplex PCR analysis for the detection of enterotoxin genes (act, alt, ast), the above mentioned Aeromonas species frequently contained enterotoxin genes, irrespective of their sources. From isolates across all the sources, act (63%) and alt (57%) genes were encountered more frequently than ast (6%). The enterobacterial repetitive intergenic consensus sequences polymerase chain reaction was used for typing of isolates and most of the isolates from water and fish were related, owing to similar ecosystem. Conclusion: A wide distribution of enterotoxin genes in Aeromonads from water and fish is a potential public health threat and molecular genotyping can be helpful to study epidemiology of the pathogen. Significance and Impact of the Study: A high proportion of isolates recovered from diverse water sources, particularly potable drinking water and fish samples carried one or more enterotoxin genes thereby indicating a potential pathogenic nature of isolates from these sources. The genetic relatedness was detected amongst many isolates recovered from water sources and fish samples indicating circulation of familiar virulent clones in the aquatic environments. [ABSTRACT FROM AUTHOR]

A survey of the pond system in Veľké Blahovo, Dunajská Streda district, Slovak Republic, confirmed the occurrence of tapeworms in carp with a prevalence of 63.5% and mean intensity of 1.7 ± 2.72. The species Khawia sinensis and Atractolytocestus huronensis were identified. We attempted to reduce the occurrence of tapeworms using a medicated feed mixture (granules) with 1% fenbendazole as active substance under controlled conditions. Faeces collected from carp (K2) were examined and the presence of tapeworm eggs was confirmed by the flotation method. Positive carp were divided into three groups; each group, labelled F1 to F3, included 15 individuals. The carp were placed in concrete pools (storage ponds) nourished by fish pond water at the peak of the vegetation period from August 7-17, 2015. The medicated feed mixture was administered to the first two groups (F1 and F2), while the third group was fed with a non-medicated feed mixture and served as the control (F3). A single dose was administered to the F1 group; tapeworm prevalence 24 hours after administration in the F1 group was 26.66% with a mean intensity of 1.3 ± 0.57. The F2 group was fed three times in total with 24-hour intervals between feeding. Tapeworm prevalence 24 hours after the last administration in the F2 group was 13.33% with a mean intensity of 2.0 ± 0.77. The prevalence in the control group was 66.66% with a mean intensity of 2.2 ± 1.62. Khawia sinensis tapeworms responded well to fenbendazole, while A. huronensis tapeworms responded poorly and, despite repeated administration of the active substance, this species remained attached to the intestinal mucosa. When compared with the control group, the reduction in the number of tapeworms was statistically significant (P = 0.05) in the F2 group; however, it was not statistically significant in the F1 group. [ABSTRACT FROM AUTHOR]

The aquaponic sistem is giving by concomitant aplication of hydroponia (plant culture without soil) and aquaculture (culture of fish). To set up a aquaponic system more stages are necessary. The environment for aquaponic sistem should be attently chosen to avoid pollution factors. Taking in consideration cold regime in our country aquaponic system was settled down inside of micro greenhouse belogs to Institute of Research and Development for Processing and Marketing of Horticultural Products Bucharest. Fishponds were building using 0.8 mm OSB panel covered with polyethylene wrap. Water physico- chemical analyzes was performed as following: temperature, oxygen dissolved (DO), nitrate, nitrite, ammonia, calcium, magnesium and phosphorus. The studies performed showed the maintenance of aquaponic system [ABSTRACT FROM AUTHOR]

The seasonality of fish marketing is a very important character for aquaculture production. We analysed data regarding the situation at the Czech market in 2015 and 2016 available in the information system of the State Agricultural Intervention Fund. The most significant volumes of freshwater fish were traded by traditional pond aquaculture companies (TPA) and approx. 1 / 3 of the all-year production was sold at the end of the year (December). Another significant time when the supply of live fish from the TPA on the domestic market slightly increased was in March and then in April, i.e. before Easter, which represented approximately one fifth of all aquaculture production. The weakest periods in terms of marketing fish of TPA were the beginning of the year, i.e. during the first two months (January and February) and the period from May to September. On the contrary, the situation was different in intensive fish aquaculture companies (IA) which had the most significant volumes traded between April and September and then in November and December. However, the sold volume of fish from IA was not strictly concentrated in a single period. [ABSTRACT FROM AUTHOR]

Aquaculture accounts for almost one-half of global fish consumption. Understanding the regional impact of climate fluctuations on aquaculture production thus is critical for the sustainability of this crucial food resource. The objective of this work was to understand the role of climate fluctuations and climate change in subtropical coastal estuarine environments within the context of aquaculture practices in Heʻeia Fishpond, Oʻahu Island, Hawaiʻi. To the best of our knowledge, this was the first study of climate effects on traditional aquaculture systems in the Hawaiian Islands. Data from adjacent weather stations were analyzed together with in situ water quality instrument deployments spanning a 12-year period (November 2004 –November 2016). We found correlations between two periods with extremely high fish mortality at Heʻeia Fishpond (May and October 2009) and slackening trade winds in the week preceding each mortality event, as well as surface water temperatures elevated 2–3°C higher than the background periods (March-December 2009). We posit that the lack of trade wind-driven surface water mixing enhanced surface heating and stratification of the water column, leading to hypoxic conditions and stress on fish populations, which had limited ability to move within net pen enclosures. Elevated water temperature and interruption of trade winds previously have been linked to the onset of El Niño in Hawaiʻi. Our results provide empirical evidence regarding El Niño effects on the coastal ocean, which can inform resource management efforts about potential impact of climate variation on aquaculture production. Finally, we provide recommendations for reducing the impact of warming events on fishponds, as these events are predicted to increase in magnitude and frequency as a consequence of global warming. [ABSTRACT FROM AUTHOR]

The present study was carried out to study the feeding habits of Labeo rohita from culture ponds of Gho-Manhasa fish farm, Jammu. Monthly samples were collected from the ponds to study the gut contents. In case of L. rohita in LrfI (lowest size group) and LrfII, LrfIII 40 guts/group, LrfIV 50 guts (due to non-availability of the size categorized) and 120 guts each in case of LrfV and LrfVI (largest size group) were analysed. For every group 10 guts/month were analysed to study feeding ecology in case of L. rohita. Individual stomach fullness scale was estimated to a subjective scale, ranging from 0 (empty) to 5 (full). The results so obtained were used to compute percentage volume of food items in the gut (%V), percentage of occurrence of guts having particular food item (%O) and Index of preponderance (IOP). The food of Labeo rohita consisted of plant (algae and macrophytes) and animal matter (protozoa, rotifers, cladocerans, copepods, molluscs, annelids and insects) besides unidentified matter (UM), sand/mud and detritus. Of the total 420 specimens analyzed, only 84 (20%) were found with empty guts and 336 (80%) were found with food components. Index of Preponderance (IOP) revealed that algae, along with protozoans, rotifers and cladocerans were the most preferred food items in the smaller size groups and marked a decline as the size of the fish increased. In the advanced stages, macrophytes, detritus and sand/mud were found to form a major share of food. Subsequently rohu has been categorized as omnivore-planktophage in early stages of life and herbi-omnivore in adult stages. [ABSTRACT FROM AUTHOR]

Fishponds exhibit high natural retention potential for phosphorus, which enters the ponds from non-point, diffuse and point sources, as well as from aquaculture management. Results of phosphorus mass balance monitoring of nine large fishponds (60-449 ha) over 2010-2014 revealed total phosphorus retention ranging between −66 % (sink) and +52 % (release) of the P loads from inflows, i.e. specific P retention varied between −7.83 g m (sink) and 1.00 g m (release) of surface area, per one fish production cycle. Retention of P was eliminated by application of fertilizers (with simultaneous fish feed application) during fish production process and/or by massive P release from fishpond sediments after previous heavy loads. P retention could be increased by preference of surface water outflow instead of bottom discharge and/or also by minimizing of emissions of suspended sediment particles during a fish harvesting. The real role of fishponds in transport processes of P throughout a watershed could be eruditely assessed only by following newly proposed method called 'new approach' when P input (via inflows) and P output (via outflows) are compared with natural fishpond ability to retain P, which is determined by a simple model proposed by Hejzlar et al. (2006). For evaluation of effect of actual fishery management, the 'culture-balance' method is suitable too. If the P inputs (stocked fish, fertilizing, feeding) and outputs (harvested fish) derived from fishery practice were in balance, the P retention did not decline. However, in condition of inputs > outputs, the P retention appreciably ceased or was totally eliminated. It was concluded that fishponds could serve as an important sink of P transported throughout a watershed even under semi-intensive fish (common carp) production condition. [ABSTRACT FROM AUTHOR]

India produced 8.29 million tonnes of fish in 2010-2011. The industry contributes nearly INR 200 trillion to the national economy, forming 1.4 percent of national gross domestic product (GDP) and 5.4 percent of Agricultural GDP. At present, almost 84 percent of the total inland fish production, in the country is contributed by freshwater aquaculture amounting to 3.9 million tonnes in 2008-09. Further, the potential of the vast freshwater resources covering 6.7 million hectare is yet to be fully realized. The freshwater aquaculture which began as small scale activity of stocking ponds with fish seed collected from riverine sources during early fifties in rural Bengal has now transformed into a major economic activity in almost all states. There is a further need to make the sector more vibrant so as to achieve the predicted target of 15 kg per capita fish availability in the country by 2030.

Pisciculture by using composite effluent of Kolkata city is a common indigenous practice in East Calcutta Wetlands (ECW), a Ramsar site in India. Apprehension over the consequences of heavy metal pollution through this practice led to the present study to examine metal accumulation related histological changes in gill and liver tissues of Tilapia ( Oreochromis niloticus ) cultivated in the wastewater fed fishponds of ECW if any. Further, induction of metallothionein, in liver tissues of the same fish was also studied. Concentration of metals (chromium(Cr), manganese(Mn), Iron(Fe), Copper(Cu), Zinc(Zn) and lead(Pb)) were evaluated and found higher in both water and bottom sediment of the wastewater fed fishponds. In fish, liver was the major site for accumulation of metals with a metal profile of Fe > Cu > Zn > Mn > Cr > Pb. Microscopic studies including optical, scanning electron microscopic (SEM), transmission electron microscopic (TEM) and atomic force microscopic (AFM) studies showed considerable changes. Higher expression of metallothionein was found in the liver of contaminated fish hepatocytes through flow cytometry, immunohistochemistry (IHC) and immuno-gold labelling (IEM). It is assumed that chronic exposure of different metal complexes lead to tissue-specific changes in organisms which may also reflect their potential to adapt survival strategies. [ABSTRACT FROM AUTHOR]

The article presents the technology of conceptual modeling of the growing carp fishpond ecosystem of the warm-water farm. The block diagram of the conceptual model, which is a modification of the known conceptual models of fishpond ecosystems, includes four species of carp fish family - carp, grass carp, white and variegated silver carp. The model takes into account six control functions that characterize the introduction of artificial feed and mineral fertilizers into the ecosystem of the pond. It is assumed that the appropriate mathematical model will take into account the influence of climatic factors - water temperature and solar radiation intensity. A distinctive feature of this conceptual model from other models, first of all, is that it is the first time as a special object of study is a variegated silver carp. The ultimate goal of this conceptual study is to identify patterns of functioning of the ecosystem of the carp fishpond, with the ability to manage its biological processes that will be used to increase its fish production. It is concluded that the developed block diagram of the conceptual model, reflecting the main processes of transformation of matter in the carp fishpond, can meet the conditions of a highly productive ecosystem only if the biological processes of all parts of the biotic chain will proceed at a highly productive level. [ABSTRACT FROM AUTHOR]

• Multi-residue analysis for 151 chemicals in fish was developed and validated. • Captiva EMR-Lipid cartridge showed better protein removal efficiency than QuEChERS. • LC-QTOF-MS/MS combined with Captiva EMR-Lipid cartridge showed good performance. • 867 chemicals were tentatively identified in cultured fish by nontarget screening. An effective analytical method for target and non-target screening of multi-class emerging organic chemicals in aquaculture fish muscle samples using liquid chromatography coupled with high resolution time-of-flight mass spectrometry (LC-QTOF-MS/MS) was reported. Two sample pretreatment methods (QuEChERS and Captiva EMR-Lipid cartridge) were compared and assessed for 151 organic compounds covering a wide range of log Kow (-1.37—11.51) in freeze-dried fish samples. Captiva EMR-Lipid cartridge outperformed QuEChERS by high detection frequency (> 87.5%) and effective matrix removal with satisfactory standard deviation of the compounds (< 20%), and meanwhile provided acceptable recoveries for most organic chemicals at three spiking concentration levels (10, 50, and 100 ng g−1). Spiking experiments suggested that the developed non-target screening workflow showed further convincible identification results with over 83.3% of the chemicals confirmed at even low spiking levels. A list of 867 organic chemicals were tentatively identified in fish samples collected from fish ponds with 21 of them classified as high confidence levels (L1 and L2). The results showed that the simplified analytical strategy can be applied for the quantification and screening analysis of a broad range of emerging organic chemicals in fish samples. [ABSTRACT FROM AUTHOR]

Abstract: Development of a prototype-mechanized fish harvesting system for carp from a rectangular shaped fishpond is described in this paper. The system consists of motorized trolleys on the longer dykes of fishpond, rail, boom pipe, netting arrangement and ON/OFF arrangements. The trolleys move on the rail tracks with constant speed of 3m/min and takes about 15min to complete the harvesting operation. The overall mean harvest efficiency of Indian major carps (IMC) with mechanized fish harvesting system has been estimated to be around 80% per operation. The whole harvesting operation is done mechanically except collection of harvested fishes at the end of operation, which presently requires two persons getting into the pond and lifting out the fishes from the net. [Copyright &y& Elsevier]

The distributions of trace metals (Pb, Cd, Cr Mn, Zn and Cu) in water, sediment, plankton and four fish species (Labeo rohita, Catla catla, Pangasius pangasius and Cirrhinus mrigala) from fishponds of Kolleru Lake, India were determined using atomic absorption spectroscopy. The concentrations of lead (0.01–0.03mg/l) and copper (0.01–0.08mg/l) in water and cadmium (3.0–9.0mg/kg), chromium (47–211mg/kg) and copper (10–64mg/kg) in sediment were above the EPA threshold effects level (TEL) and are of biological concern. The abundance orders of metals were Mn>Cd>Cu>Pb in water, Mn>Cr>Zn>Cu >Pb>Cd in sediment and Cu>Mn>Cr>Zn>Pb>Cd in plankton. The concentrations of the metals in the muscles of these four fish species apparently decrease in the order Zn>Cu>Cr>Mn=Pb>Cd and were well below WHO permissible limits that were safe for human consumption. [Copyright &y& Elsevier]

More than 20 years after the Water Framework Directive was adopted, there are still major gaps in the sanitary status of small rivers and waterbodies at the head of basins. These small streams supply water to a large number of wetlands that support a rich biodiversity. Many of these waterbodies are fishponds whose production is destined for human consumption or for the restocking of other aquatic environments. However, these ecosystems are exposed to contaminants, including pesticides and their transformation products. This work aims to provide information on the distribution, diversity, and concentrations of agricultural contaminants in abiotic and biotic compartments from a fishpond located at the head of watersheds. A total of 20 pesticides and 20 transformation products were analyzed by HPLC-ESI-MS/MS in water and sediment sampled monthly throughout a fish production cycle, and in three fish species at the beginning and end of the cycle. The highest mean concentrations were found for metazachlor-OXA (519.48 ± 56.52 ng.L−1) in water and benzamide (4.23 ± 0.17 ng g−1 dry wt.) in sediment. Up to 20 contaminants were detected per water sample and 26 per sediment sample. The transformation products of atrazine (banned in Europe since 2003 but still widely used in other parts of the world), flufenacet, imidacloprid (banned in France since 2018), metazachlor, and metolachlor were more concentrated than their parent compounds. Fewer contaminants were detected in fish and principally prosulfocarb accumulated in organisms during the cycle. Our work brings innovative data on the contamination of small waterbodies located at the head of a basin. The transformation products with the highest frequency of occurrence and concentrations should be prioritized for further environmental monitoring studies, and specific toxicity thresholds should be defined. Few contaminants were found in fish, but the results challenge the widely use of prosulfocarb. [ABSTRACT FROM AUTHOR]

Abstract: The objective of the present study is to provide a basis for the development of a standard on the concentration of heavy metals in reclaimed water used for edible fish aquaculture, focusing on the four heavy metals addressed by the Israel standard for food quality (arsenic, cadmium, lead and mercury). A series of experiments were carried out on three commercial fish species of differing feeding habits and complementary measurements were made in fish growing in a reservoir with secondary treated effluent. In a field experiment the fish were raised on natural food and on pelleted feed, in reclaimed wastewater and in freshwater. In laboratory experiments, the fish were raised in aquaria while exposing them to heavy metals supplied in the pelleted feed or dissolved in the water. In the field experiment with fish growing in tertiary treated reclaimed water during five months, no detectable levels of the four tested heavy metals were found in fish flesh (no analyses in internal organs performed). In fish reared during two years in secondary treated reclaimed water, no detectable levels of heavy metals were found in fish flesh, but the concentrations of Cd and Pb in liver and bones of some fish were above the food standard. Laboratory experiments on rearing fish while exposing them to water and pelleted feed with increasing levels of heavy metals, revealed detectable levels of these heavy metals in fish flesh, bone and mainly in liver. The standards on reclaimed water for unrestricted irrigation are a good basis for the development of a water quality standard for growing fish in reclaimed water, because fish can be grown in the reservoirs used to storage the reclaimed water and/or this is the reclaimed water that can be used to fill fish ponds. Except for Hg, the proposed Israel requirements for heavy metals in reclaimed water used for unrestricted irrigation (As=0.1 mg/l, Cd=0.01 mg/l, Pb=0.1 mg/l, Hg=0.002 mg/l) are safe regarding the consumption of flesh from fish reared in reclaimed water, even if the growing season is long (up to two years). These requirements are not equally safe regarding the consumption of liver (and probably other viscera). [Copyright &y& Elsevier]

The objective of our study was to survey the accumulated 2-methylisoborneol (MIB) and geosmin (GSM) in fillets of five important farmed fish species in Hungarian aquaculture in relation to MIB and GSM concentrations in water and sediment in the aquatic systems where they were raised: (the planktivorous silver carp (Hypophthalmichthys molitrix), the herbivorous grass carp (Ctenopharyngodon idella), the bottom-feeding omnivorous common carp (Cyprinus carpio), the omnivorous tilapia (Oreochromis niloticus) and the carnivorous African catfish (Clarias gariepinus)). Water, sediment and fish samples were collected from different experimental aquatic systems which included a combined aquaculture-algae (CAA) system, effluent-fed fishponds, a pond recycling system and a traditional fishpond. MIB and GSM contents were extracted with distillation-headspace solid-phase - microextraction (SPME) and extracts analysed by GCMS, Results showed that off-flavour contents in fish fillets were related to the feeding habits of the studied fish species. Higher GSM concentrations were found in the fillet of bottom-feeding common carp than in the silver carp or African catfish in all studied aquatic systems. Usually, low GSM concentrations were detected in the water of fishponds but sometimes the levels of this odour compound in carp fillet were well above the limits of human detection. This suggests that the off-flavour tainting of common carp may originate from the sediment or benthic algal/actinomycete sources. Negligible MIB levels were found in all samples in all of the studied aquatic systems. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess concentration and correlation of selected heavy metals and level of some microbiological indicators (total bacteria count-TBC, mesophilic anaerobic sporulating bacteria-MASB) in the muscle of common carp ( Cyprinus carpio ). Fish were collected by seine net within the frame of pondfishing, in October (pond Horné Obdokovce—pond A) and December (pond Budmerice—pond B) 2003. Concentrations of selected metals were measured using an atomic absorption spectrophotometer Pye Unicam SP9. The concentrations of metals (mg/kg wet weight basis) ranged as follows: Fe 3.47–15.15; Mn 0.14–0.42; Zn 3.47–9.52; Cu 0.24–1.32; Co 0.05–0.17; Ni 0.07–0.42; Cr 0.08–0.19; Pb 0.11–0.30; and Cd 0.01–0.05. The count of MASB and TCB (in CFU/g) varied as follow: 1.12–7.76 × 10 3 and 0.03–7.59 × 10 6 , respectively. Significant differences (P Zn > Cu > Mn > Pb > Cr > Ni > Co > Cd; (Pond-B) Fe > Zn > Cu > Mn > Pb > Ni > Cr > Co > Cd. [ABSTRACT FROM AUTHOR]

The article presents a study on the determination of biopesticide azadirachtin in fish samples and in samples of water of fish ponds. The preparation of the fish samples for the determination in gas chromatography and high performance liquid chromatography is discussed. The results have indicated that the recoveries of azadirachtin in fortified fish samples were higher than 90%. It is concluded that the use of methanol as extraction solvent was efficient for the extraction of azarirachtin.

We aimed to assess whether prey organisms with limited large-scale dispersal abilities are locally adapted to prevailing predator regimes by studying how chemical cues from predatory fish affected the behavior of Gammarus pulex (Amphipoda) from ponds with and without fish. We also examined, in the laboratory, the Fl generation from each pond by incubating them with or without cues from predatory fish. The potential benefits of a behavioral avoidance response were also assessed in an experiment in which G. pulex from the different ponds and incubations were exposed to fish predation. G. pulex from fish ponds increased their refuge use when exposed to fish cues, whereas populations from fishless ponds reduced their refuge use. The Fl generation responded similarly to their parents. Only the F1 generation from fish pond populations responded with more pronounced antipredatory behavior when raised in fish water. Moreover, both the original and the Fl generation of fish pond G. pulex survived longer when exposed to fish predation than those from fishless ponds, independent of whether they were raised in fish water or not (Fl). Our results suggest that the behavioral response to predator cues in G. pulex is an inherited trait, i.e., a local adaptation to prevailing predator regimes. [ABSTRACT FROM AUTHOR]

This study analyzed the pond, gut region and fish species influences on the gut bacterial communities in three Indian major carps (IMCs), rohu (Labeo rohita), catla (Catla catla) and mrigal (Cirrhinus mrigala), using high-throughput sequencing. Foregut and hindgut communities from IMCs cohabiting in three polyculture ponds were investigated. The communities of all three IMC's were dominated by Proteobacteria (accounting for 15–40% of sequence reads), Firmicutes (16–21%), Actinobacteria (18–34%), and Bacteroidetes (6–19%). Catla presented a significantly higher abundance of Proteobacteria (40.4%) and Fusobacteria (1.8%) than mrigal (14.6% and 0.46%, respectively) and rohu (24.4% and 0.42%, respectively). Catla also contained the lowest relative abundance of Bacteroidetes (5.9% vs. 17.7% for mrigal and 18.7% for rohu). At deeper levels the relative abundances of a number of OTUs differed between the species. Despite this, a core microbiota were observed. Comparing the presence/absence of OTUs (unweighted distances), all beta diversity parameters (PERMANOVA, ANOSIM, distance-based redundancy analysis and delta) revealed significant differences in the three factors studied: gut region, fish species and ponds. These results suggested that gut microbiome might have resulted from niche partitioning and selective pressures that could be species-specific. • Comprehensive high-throughput analyses of gut microbiota in 3 polycultured Indian major carps considering pond effect. • 1971569 sequences were retained from 54 samples (18 per species, 2 gut regions) corresponding to 3202 OTUs. • Beta diversity parameters revealed significant differences within gut regions, fish species and source ponds. • Interspecies and intraspecies variations in the microbiome at phyla-genus taxonomic levels together with a core microbiota. • Gut microbiome might have resulted from species-specific niche partitioning. [ABSTRACT FROM AUTHOR]

• Swine farm wastewaters (SFWs) led to elevated steroid levels in the environment. • SFWs resulted in masculinization, defeminization and feminization in fish. • Steroid hormones in waters accounted for 53.4% of adverse effects in fish. • The adverse effects in fish from the ponds corroborated those from the rivers. Swine farm wastewaters (SFWs) are generally discharged either directly into nearby rivers or into fish ponds as a source of fertilizer/food for aquaculture in China. SFWs contain various contaminants including steroid hormones. However, there is an extreme paucity of data on their effects in fish populations. Here we investigated the endocrine disrupting effects of SFWs in G. affinis from 2 rivers (7 sites) and 2 fish ponds (2 sites) receiving SFWs and a reference site in Guangdong Province, China. In this study, a total number of 3078 adult western mosquitofish (Gambusia affinis) were collected and the sex ratio was determined. In addition, secondary sexual characteristics were examined and the transcriptional levels of target genes were analyzed. The results showed the mosquitofish populations had a significant increase in male-to-female ratio from 7 sites (including 2 fish ponds) among the 9 sampling sites. The hemal spines of females were masculinized at most sites while the hemal spines of males were feminized at approximately half of the sites (including 2 fish ponds). Significant reduction in vitellogenin (Vtg) mRNA expression was observed in females from 2 sites (including RS7) while elevated Vtg mRNA expression was noticed in males from 2 sites along the rivers (including RS7). Redundancy analysis showed that androgens in the water samples were closely related with male-to-female ratio in the mosquitofish populations and the masculinized hemal spines of females. The findings from this study demonstrated that discharge of SFWs could result in occurrence of both masculinized females and feminized males in mosquitofish population. [ABSTRACT FROM AUTHOR]

• Fishponds with similar management can have different macrophyte assemblages. • Fishpond macrophytes are influenced by farm management and water transparency. • High fish stock leads to decrease in macrophyte abundance and diversity. • Production stages with low fish stock support recovery of fishpond macrophytes. Seasonal and inter-annual macrophyte assemblage dynamics were surveyed in ten nursery and ten main fishponds stocked primarily with common carp Cyprinus carpio fry and with common carp being reared to market size, respectively. The results indicate a significant difference in macrophyte species number and abundance between the nursery and main fishponds, with up to 24.5% of the variation in macrophyte species distribution patterns explained by fishpond management type (nursery or main) and up to 6.7% by water transparency. Fish biomass used as a fish stock proxy explained up to 13.9% of variability. Although not significant, differences in species number and abundance were found (i) between spring and summer survey periods during the growing season with both species number and abundance usually decreasing in summer, and (ii) between years of the farming production cycle with a higher species number and abundance typically found in the first year of the farming cycle in the nursery fishponds. The results increase knowledge of fishpond macrophyte assemblages and may be of interest for conservation of aquatic habitats. [ABSTRACT FROM AUTHOR]

Water quality plays an important role in ensuring the healthy growth of aquatic living. Fish in ponds release nitrogen, phosphorus, ammonia, nitrates and organic waste. The presence of these chemicals in water leads to an increment in the pH level of the pond water, which could affect the growth of the fish. Therefore, it is vital to have an effective filter system for pond water to remove the unwanted waste. At current literature, the filtering effectiveness of activated carbon and zeolite in fresh water pond systems are remained inexplicit. In this work, a lab-scale filtering system was set up to study the ammonia removal efficiency of activated carbon and zeolite. The efficiency of these two types of filtering media was first studied separately and then combined as a hybrid filter with a weight ratio of 1:1. The effectiveness of the single filter media and hybrid media filter were evaluated based on the measurement of the concentration of ammonia, nitrite and nitrate, and the pH level. It was found that the hybrid filter – a combination of activated carbon and zeolite – tended to have higher efficiency in maintaining good water quality compared to the single media system; the ammonia level was reduced from 4 mg/L to 1 mg/L in 2.5 days. The greater the amount of the hybrid filter media presents in the system, the better the conversion rate of ammonia to nitrate. A combination of activated carbon and zeolite (150 g each) was found to be able to maintain suitable water quality (1 mg/L ammonia, 0 mg/L nitrite, <50 mg/L nitrate, 6.8–8.0 pH) for fish. [ABSTRACT FROM AUTHOR]