Thesis (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (ℓ. 83-89)

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

This investigation explored the use of microcosms as a tool for studying the dynamics of tropical aquaculture ponds. The potential use of rabbit excreta as a pond fertilizer in integrated farming systems was also investigated. Twelve insulated fiber glass tanks were utilized as microcosms to simulate earthen ponds. Seven hand-sexed Nile Tilapia O. niloticus) were stocked per tank, and microcosm performance was observed for a 90- day experimental period. Three rabbit excreta loading rates corresponding to 50 and 75 kg/10,000 m³ /day, and a continuously adjusted manure loading rate were assessed. The fertilizer treatments were compared to a control treatment where fish were fed on a prepared food. Water quality variables and fish performance were regularly monitored. Nitrogen and phosphorous content of rabbit excreta were measured. The dynamics of the microcosms were similar to warm water earthen ponds with respect to physical and chemical characteristics. Statistical differences were detected between control and fertilized treatments in relation to dissolved oxygen levels, net primary productivity, total alkalinity, total ammonia and orthophosphate levels. Primary productivity was influenced more by light intensity and penetration than by nutrient limitation. Rabbit excreta overloading was observed in the 75 kg treatment. Fish growth was greatest in the control treatment, but it was not statistically different from the continuously adjusted fertilizer treatment (Pondclass) (0.0065 and 0.0056, respectively). Low daily fish gains were observed in the 50 and 75 kg treatments. Low dissolved oxygen and high total ammonia were concentrations resulted in low weight gains and condition indices of fish in the 50 and 75 kg treatments. Extrapolated fish yields corresponded to 6,205, 4,563, 3,686, 4,869 kg/ha/year for control, 50 kg, 75 kg and Pondclass treatments, respectively. The observed yields are comparable with field experiences in real ponds. The continuously adjusted treatment showed the lowest manure conversion ratio (3.85) in the fertilized treatments. The nitrogen content of rabbit excreta varied according to rabbit size, presence or absence of urine plus water waste, and food droppings. Urine plus water waste provided 28 % of the total nitrogen content in rabbit excreta, whereas food droppings provided 12 %. Rabbit urine may play an important role in aquacultural systems because it contains a large fraction of nitrogen in inorganic forms which are readily utilized for algal growth. Other rabbit excreta characteristics such as buoyancy may be advantageous in aquacultural systems. Rabbit excreta is a potentially rich source of fertilizer for use in fish ponds. / Graduation date: 1992

Baigiamajame darbe nagrinėjama keturių Lietuvos pramoninės žuvininkystės ūkių į aplinką išleidžiama tarša (tiekiamo ir išleidžiamo vandens) pagal skendinčias medžiagas, BDS7, bendrą azotą ir bendrą fosforą ir pateikiamos rekomendacijos tvenkininių ūkių vandens kokybei gerinti. Darbo objektas: paviršinis vanduo. Darbo metodai – vertinama paviršinio vandens kokybė žuvininkystės ūkiuose aukščiau ir žemiau tvenkinių (tiekiamo ir išleidžiamo vandens). Darbo rezultatai. Išanalizavus daugiamečius žuvininkystės ūkių vandens kokybės tyrimų duomenis, gauti tokie rezultatai: 1. Skendinčiomis medžiagomis labiausiai užteršti: 1.1. UAB „Daugų žuvis“ tvenkiniai: (priimtuvas – Varėnės upė – 38,0 mg/l, 2009 m.) – žemiau tvenkinių; (priimtuvas – Žižmos upė – 37, 0 mg/l, 2007 m.) – žemiau tvenkinių. 1.2. AB „Išlaužo žuvis“ tvenkiniai: (priimtuvas – Jiesios upė – 47,0 mg/l, 2009 m.) – aukščiau tvenkinių; (priimtuvas – Jiesios upė – 54,0 mg/l, 2009 m.) – žemiau tvenkinių. Nežymiai skendinčių dalelių kiekį viršijo ir Šilavoto poskyrio tvenkiniai (priimtuvas – Jiesios upė – 27,0 mg/l, 2009 m.) – žemiau tvenkinių. 2. Nagrinėtuose žuvininkystės tvenkiniuose nei BDS7, nei bendras azotas, nei bendras fosforas neviršijo leistinų normatyvinių rodiklių. Apibendrinus gautus rezultatus peteikiamos sekančios rekomendacijos tvenkininių ūkių vandens kokybei gerinti: 1. Norint išvengti padidintų skendinčių dalelių koncentraciją pageidautina pagal galimybes didžiają paduodamo vandens dalį kaupti tam... [toliau žr. visą tekstą] / The thesis examines four Lithuanian industrial fish farms in releasing pollution (water supply and discharge) by TSS, BDS7, total nitrogen and total phosphorus and recommendations of farm ponds to improve water quality. Working properties: surface water Working methods - evaluating the quality of surface water in the farms above and below the pond (water supply and discharge). Results. Analysis of many fish farms on water quality survey data, the following results: First TSS most contaminated: 1.1. JSC "Daugų Pond: (Receiving - Varėnė River - 38.0 mg / l, 2009.) - below the dams; (Receiving - Zizmai River - 37, 0 mg / l, 2007.) - below the ponds. 1.2. AB Išlaužo Fish Pond: (Receiving - Jiesia River - 47.0 mg / l, 2009.) - above the pond; (Receiving - Jiesia River - 54.0 mg / l, 2009.) - below the ponds. Slightly higher than the amount of suspended solids and Šilavotas subdivision ponds (Receiving - Jiesia River - 27.0 mg / l, 2009.) - Below the ponds. Second INVESTIGATED fishponds than BDS7 than the total nitrogen or total phosphorus exceeded the permissible normative indicators. Summarizing the results peteikiamos next recommendation farm ponds to improve water quality: First to avoid increase of suspended particles concentration preferably by possibilities to a large flow of accumulating a dedicated, larger ponds or specially equipped stores and settle only part of the load of suspended particles continue growing pond filling. Second Extend pond filling period... [to full text]

Thesis (M.S.)--Louisiana State University. / Vita. Bibliography: leaves 55-56.

M.Sc. (Zoology) / Please refer to full text to view abstract

Links between the pond and surrounding land for horticulture is a distinctive feature of farming households in Bangladesh. It was hypothesised that the role of fishponds in integrated aquaculture systems has potential towards improving livelihoods and poverty alleviation. Rural and peri-urban settlements in Mymensingh District, Bangladesh were selected for assessing the importance and role of pond-dike systems on the livelihoods of households of different socio-economic level. The study was carried out in view of the sustainable livelihood approaches of the Department for International Development, U.K. Participation of all levels of stakeholders was ensured in the first and last phase of the study. The combination of quantitative and qualitative analysis at community and household level was a major strength and challenge of the study, and was used to explore the potential of integrated farming and factors that undermine such potential to contribute to a sustainable livelihood. The research commenced with a comprehensive situation appraisal and baseline survey to explore the context and characterize farming systems, followed by a longitudinal household survey to understand the effect of seasons on livelihoods. Households with access to ponds were identified as active or passive integrators based on a simple set of criteria and their resources and livelihoods assessed in comparison with non-pond households. During the last phase of the study a farmer participatory research (FPR) trial, based on a priority issue identified during the 1st phase of the study, was launched to investigate the potential of the integrated systems. The situation appraisal conducted within four communities revealed the effects of gender, well-being and location on farmers' regular activities and food consumption patterns. Fish culture was equally important as an enterprise among richer and poorer men, whereas vegetable cultivation was more important to men than women but wealth and location also affected its importance. Lack of knowledge was a particular problem for farmers growing fish and vegetables in the rural areas. Fish disease, high price of input, lack of money were also identified as constraints by fish producers. The expected use and current use of ponds, problems and benefits associated with fish culture were also found to be affected by groups emphasising vegetable, orchard and fish culture within their systems. The role of the pond for family use, which was a major objective for pond construction, was found to be significantly different between rural and peri-urban areas. Fish culture is now the dominant use of ponds for households irrespective of their focus on vegetable, orchard or fish production and they are utilised less for general domestic use. Ponds are relatively more important as a source of irrigation water in rural than in peri-urban communities. Significant differences were observed between locations and well-being categories for the percentage of fish retained for consumption and that sell. Rice bran was the most commonly used pond input (80% of all pond households) but active integrated farmers applied rice bran more frequently than passive groups (91 compared to 63 times/season). ‘Ease of production’ was a major incentive for farmers to integrate fish and vegetable production and this opinion was related to household type i.e. active integrators were more aware and confident about the practice. The literacy levels of household heads, access to information and capital and contact with formal and informal institutions of active producers and the better-off households was significantly higher than other groups and poorer households respectively. It is revealed from the longitudinal households’ analysis that the consumption pattern in terms of food types and amount are linked with income, expenses and food availability in different well-being categories between seasons across locations. The empirical analysis showed that as active households’ income increased, expenditure on food purchases, agricultural labour, pond inputs and poultry per household also increased. However, on-farm contributions as a source of fish and vegetables were important during the lower income and least productive months. Performance of integrated farming systems varied by location. Resource base, accessibility to market and information played key roles in the development of integrated farming system in the study area. Active integrated households in peri-urban areas, in response to higher demand in the nearby market, produced significantly more fish and vegetables than those in the rural areas. The result showed clearly the need for due consideration of these factors while promoting IAA systems in Bangladesh. Farmer participatory research showed that production of fish could be increased by a substantial level through increasing pond nutrient inputs rather than stocking an additional species (tilapia), although this may be related to the ‘improved’ nutrition used by farmers still being well below the level required for optimal tilapia performance. Rural households benefited more than peri-urban through direct consumption of both fish and vegetables; in contrast peri-urban households benefited more through cash sales of both fish and vegetables than rural households. Higher production did not lead to increased consumption, rather households benefited financially through selling fish. Similar production levels of vegetables between groups followed different levels of fish culture practices suggesting that increased investment in fish production is complementary rather than competitive with associated vegetable production. It could be concluded that considerable potential exists for further integration and development of pond-dike systems, which could contribute towards improved livelihoods of both better off and worse off people.

Thesis (Ph.D.)--Mississippi State University. Department of Agricultural and Biological Engineering. / Title from title screen. Includes bibliographical references.

Thesis (M.S.)--Mississippi State University. Department of Wildlife and Fisheries. / Title from title screen. Includes bibliographical references.

This study aimed at using different types of food wastes as major sources of protein to replace the fish meal used in fish feeds to produce quality fish. The major objectives were to (1) investigate the variations of metalloid/metals, polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in the fish ponds (pond mud and water), and food wastes used as fish feeds; (2) analyze bioaccumulation and biomagnification of pollutants in the food chains; and (3) evaluate the potential health risks of exposure (to these pollutants) via dietary intake of fish fed with food waste feeds. The traditional fish farming model was used to culture low trophic level fish: a filter feeder (bighead, Aristichthys nobilis), a herbivore (grass carp, Ctenopharyngodon idellus) and a bottom feeder (mud carp, Cirrhina molitorella), which are more environmental friendly as they can utilize more solar energy. Furthermore, low-trophic level fish are less susceptible to the accumulation of toxic chemicals. Two types of food wastes (mainly containing cereal (Food Waste A) and meat waste meal (Food Waste B)) were used as the major source of protein to replace the fish meal in fish feed to culture fish. The concentrations of metalloid (arsenic (As)), metals (mercury (Hg), cadmium (Cd), chromium (Cr), lead (Pb), zinc (Zn), copper (Cu) and nickel (Ni)) in water, suspended particulate matter and sediment of the 3 experimental fish ponds located in Sha Tau Kok Organic Farm were monitored (bi-monthly during the first half year and tri-monthly during the second half year) and the results were similar to or lower than those in the commercial fish ponds around the Pearl River Delta (PRD) region. Results of the health risk assessments indicated that human consumption of grass carp (a herbivore) which fed food waste feed pellets would be safer than other fish species (mud carp, bighead carp and largemouth bass). There were no or lower magnifications, and low concentrations of metalloid/metals contained in the ponds indicated that the practice of traditional pond management by draining pond water regularly can provide a better fish pond habitat for birds and other wildlife. Furthermore, the use of food waste instead of fish meal (mainly consisted of contaminated trash fish) further reduced Hg accumulation in the cultured fish. During October 2011 - December 2012, the concentrations of PAHs and OCPs in three experimental fish ponds were monitored (bi-monthly during the first half year and tri-monthly during the second half year). The results were similar to or lower than those obtained in commercial fish ponds around the PRD region. The mean concentrations of .PAHs and .OCPs in sediment and fish collected from the experimental fish ponds during the 2nd half year (May 2012 to December 2012) were significantly higher (p<0.05) than those in the 1st half year (October 2011 to April, 2012). .PAHs and .DDTs in the two species of fish (grass carp and bighead carp) were significantly increased (p<0.05) with time, and PAHs and DDTs in grass carp and bighead carp fed with commercial fish feed pellets (control group) were significantly higher (p<0.05) than the fish fed with food waste pellets (Food Waste A and Food Waste B). Fruit, vegetables, bone meal and meat products were the major sources of PAHs and OCPs contamination for producing Food Waste A and Food Waste B. No significant increases in PAHs and DDTs concentrations with trophic levels were observed in the experimental ponds, showing that PAHs were not biomagnifed in the omnivorous food chains (plankton, grass carp, bighead carp and mud carp). DDTs were lower magnifications than those predatory food chains (plankton, trash fish, and largemouth bass) in farmed ponds. There was a very low cancer risk for PAHs and DDTs exerted on humans via consumption of bighead carp, grass carp and mud carp (fed with food waste and commercial pellets). Furthermore, the use of food waste instead of fish meal (mainly consisted of contaminated trash fish) further reduced accumulation of PAHs and DDTs in the cultured fish.PAHs and DDTs exerted on humans via consumption of bighead carp, grass carp and mud carp (fed with food waste and commercial pellets). Furthermore, the use of food waste instead of fish meal (mainly consisted of contaminated trash fish) further reduced accumulation of PAHs and DDTs in the cultured fish. The present results revealed that recycling of food waste for cultivating low trophic level fish (mainly bighead carp and grass carp) is feasible, which will also ease the disposal pressure of the large volume of food waste, a common problem encountered in densely populated cites such as Hong Kong.