• 한국양식학회지
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• 제14권2호
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• pp.67-71
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• 2001

Phosphorus is an essential element for growth and metabolism in fish. However high levels of phosphorus in the feed can lead to poor water quality of pond, and can also be a potential source of pollution, when pond water is released to the environment. In this study phosphorus supplemented diets containing 0.0, 0.9 or 1.9% of (dicalcium) phosphate were offered to channel catfish and changes in water quality of ponds and phosphorus levels in fish were measured. Higher level of (1.9%) supplementation of phosphorus in diet resulted in higher concentration of T-P and SRP in pond waters. Also it produced negative effects on fish production by lowering feed coefficient and rate of increment in body weight. Surplus phosphorus can affect fish growth and water quality of pond.

• 한국환경농학회지
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• 제19권4호
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• pp.339-344
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• 2000

축산폐수를 처리하는 연못시스템의 1차연못 처리수(평균 $BOD_5\;49.1mg{\cdot}L^{-1}$, $T-N\;48.6\;mg{\cdot}L^{-1}$)를 1주에 2 - 3회 실험양어지에 공급하여 잉어의 성장을 조사하였다. 처리수 공급유량과 실험양어지의 유량이 1:4가 유지되도록 공급하였으며, 실험양어지의 평균 $BOD_5$는 $15\;-\;20\;mg{\cdot}L^{-1}$였다. 양어지에 수용한 잉어의 평균 체중은 8월에 204.2 g에서 9월과 10월에 210.4 g와 219.3 g로 각각 늘었으며 60일간 사육에서 생잔율이 82%였다. 운반 및 조사시 잉어에 주는 스트레스를 감안하면 양어지의 수질과 환경은 잉어 성장에 나쁘지 않았다고 여겨진다. 8월부터 10월 사이의 다소 낮은 성장률은 양어지의 물을 빼내고 잉어를 잡아 체중과 체장을 측정하는 과정이 잉어에 스트레스를 준데 원인이 있다고 사료된다. 월동 후인 이듬해 4월에 잉어의 평균 체중은 205.3g로 감소하였으며 전년도 10월과 비교하여 생잔율은 83%였다. 일반적으로 잉어는 월동 후에 체중이 약 10 - 20% 감소하는 경향이 있다. 양어지 실험결과 양어지의 평균 $BOD_5$가 $15\;-\;20\;mg{\cdot}L^{-1}$로 유지되면 용존산소결핍으로 잉어가 일시에 죽는 현상은 일어나지 않음을 알 수 있었다. 평균 $BOD_5$와 T-N이 각각 27.9, $30.8\;mg{\cdot}L^{-1}$인 2차연못에 체중 약 100g 정도의 잉어 10마리를 8월에 넣어 보았으나 1주일 이내에 모두 죽었다. 새벽 무렵의 급격한 용존산소결핍 현상에 원인이 있다고 사료된다. 연못시스템의 3차연못에 잉어를 직접 털어 성장을 분석하였다. 3차연못의 평균 $BOD_5$와 T-N은 각각 $19.8\;mg{\cdot}L^{-1}$, $21.0\;mg{\cdot}L^{-1}$였다. 3차연못은 2차연못에서 발생한 조류(algae)가 죽어 연못바닥으로 침전되는 마무리연못(maturation pond)으로 연못전체가 호기성을 유지하고 있었다. 3차연못에 8월에 넣은 잉어의 평균체중은 107.5g였으며 2개월 후에 165.2g으로 증가하였다. 사육 1년 후의 평균체중은 478.2g으로 약 3배 증가했으며, 1년 후의 잉어 생잔율도 86%로 높게 나타났다. 월동을 했다는 것을 고려한다면 매우 좋은 성장이다. 생잔율이 높게 나타난 원인은 측정 횟수가 적어 측정에 따른 스트레스가 적었다는 점과 3차연못의 환경조건 (수질, 먹이 등)이 잉어사육에 적합했다고 사료된다. 사료공급 없이 하${\cdot}$폐수를 재활용하는 세계 여러나라의 잉어 생산량은 약 $18\;-\;l37g{\cdot}m^{-2}year^{-1}$이다. 3차연못 잉어생산량은 $125\;g{\cdot}m^{-2}year^{-1}$로 아주 양호한 생산량이다. 산업폐수가 유입되지 않은 생활하수나 축산폐수의 처리수를 이용한 양어의 고기는 생체실험결과 인체에 해가 없다고 규명되어 왔다.$^{15,16),17)$ 축산폐수를 자연생태적으로 처리하는 연못시스템의 연못에서 잉어를 사육할 경우 연못의 수질이 2차처리수준인 $BOD_5\;20\;mg{\cdot}L^{-1}$ 정도를 유지하는 것이 적절하다고 사료된다. 연못시스템은 축산지수를 효율적으로 처리할 수 있을 뿐만 아니라, 양어의 수확으로 축산농가의 소득증대에도 기여할 수 있다.

• Journal of Ecology and Environment
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• 제35권2호
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• pp.149-155
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• 2012

Rice paddy fields have been recognized as an alternative habitat for avian wetland foragers, and fish-rice farms have become a new tool in improving the abundance of aquatic animals. However, the use of the habitats by avian foragers, particularly by oriental storks ($Ciconia$ $boyciana$), was not well understood. In the present study, we investigated how a fish-rice farm influenced the abundance of aquatic animals and documented the foraging behavior of the two captive bred oriental storks in a closed semi-natural paddy field. Our results showed that the fish refuge pond (water depth 40 cm) had a higher abundance of fish whereas the areas planted with rice (water depth 20 cm) had more tadpoles and some aquatic insects. The two captive bred oriental storks captured mostly fish and aquatic insects in the rice-planted area and mostly fish in the fish refuge pond. The two oriental storks had higher foraging success and spent more time for foraging in the rice-planted area than in the fish refuge pond. This result suggests that the oriental storks might prefer foraging in the area with fish, aquatic insects, and amphibians under a greater success rate presumably due to shallow water depth in the paddy fields with a fish-rice farm.

• Fisheries and Aquatic Sciences
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• 제20권11호
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• pp.30.1-30.10
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• 2017

Small-scale fish farmers in developing countries are faced with challenges owing to their limited information on aquaculture management. Nile tilapia farmers in Teso North Sub-County recorded lower yields than expected in 2009 despite having been provided with required inputs. Water quality was suspected to be the key factor responsible for the low yields. This study sought to assess the effects of earthen pond water physico-chemical parameters on the growth of Nile tilapia in six earthen fish ponds under semi-intensive culture system in Teso North Sub-County. The study was longitudinal in nature with pond water and fish being the units of analysis. Systematic sampling was used to select five ponds while a control pond was purposively selected based on its previously high harvest. Four ponds were fed by surface flow and two by underground water. Each pond was fertilized and stocked with 900 fry of averagely 1.4 g and 4.4 cm. Physico-chemical parameters were measured in-situ using a multi-parameter probe. Sixty fish samples were randomly obtained from each pond fortnightly for four months using a 10 mm mesh size and measured, weighed and returned into the pond. Mean range of physico-chemical parameters were: dissolved oxygen (DO) 4.86-10.53 mg/l, temperature $24-26^{\circ}C$, pH 6.1-8.3, conductivity $35-87{\mu}S/cm$ and ammonia 0.01-0.3 mg/l. Temperature (p = 0.012) and conductivity (p = 0.0001) levels varied significantly between ponds. Overall Specific Growth Rate ranged between 1.8% (0.1692 g/day) and 3.8% (1.9 g/day). Ammonia, DO and pH in the ponds were within the optimal levels for growth of tilapia, while temperature and conductivity were below optimal levels. As temperature and DO increased, growth rate of tilapia increased. However, increase in conductivity, pH and ammonia decreased fish growth rate. Temperature and DO ranging between 27 and $30^{\circ}C$ and 5-23 mg/l, respectively, and SGR of 3.8%/day and above are recommended for higher productivity.

• 한국수산과학회지
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• 제9권4호
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• pp.257-259
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• 1976

잉어를 저밀도로 방양하고 동시에 사료중의 동물성단백질을 줄이는 실험을 하였다. 수면적 $454m^2$의 못 3개에 각 못에 평균 81.2g되는 보통잉어 72미와 평균 37.89g 되는 비단잉어 28미를 방양 189일간 사육한 결과, 동물질 $20\%$ 사료의 못에서는 보통잉어가 평균 776.2g, 비단잉어 평균 $504.2g$, 총평균, 701.1g으로 자라고, $35\%$구에서는 각각 792.9g, 539.1g, 730.1g, $50\%$에서는 각각 983.7g, 630.4g, 887.0g으로 자랐다. 이 실험에서 1ha당 생산고가 $20\%$구에서 1,352kg, $35\%$구에서, 1,495kg, $50\%$구에서 1,447kg였으므로 양어지에서의 보통생산고의 1/2에 미달되었으며 이 정도의 저밀도양어에서는 사육단백질의 량을 감소시켜서는 안된다는 결론이 나온다.

• Fisheries and Aquatic Sciences
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• 제6권4호
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• pp.194-202
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• 2003

Budgets for water, nitrogen, and chemical oxygen demand (COD) were determined in two 0.012 ha earthy-bottom ponds stocked with Israeli strain common carp at an initial stocking density of $20\;fish/m^3$. Total ammonia nitrogen (TAN) concentrations increased continuously but later decreased in pond A as a consequence of high nitrification. COD concentrations increased during the experimental period due to the accumulation of feed input. Nutrient budgets showed that feed represented $94-95\%$ of nitrogen input and about 99% of organic matter input. Fish harvest accounted for $40\%$ of nitrogen and organic matter input. Seepage and water exchange removed $15-17\%$ of nitrogen input but only $1-2\%$ of organic matter. Draining of the ponds removed $20-26\%$ of input nitrogen, mostly in inorganic forms, but removed only minus organic matter. Fish and water column respiration accounted for $39\%$ of organic matter input, and benthic respiration accounted for $7-12\%$ of organic matter input. No significant change of nitrogen and organic matter in both pond bottoms were found during the three-month growth period. The unrecovered input nitrogen, about $6.3-13\%$, was lost through denitrification and ammonia volatilization. On a dry matter basis, fish growth removed $31\%$ of total feed input and left $69\%$ as metabolic wastes.

• Asian-Australasian Journal of Animal Sciences
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• 제11권2호
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• pp.192-195
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• 1998

Biomass conversion efficiencies (B.C.E) of six fish species viz, Catla catla, Labeo, rohita, Cirrhina mrigala, Hypophthalmicthys molitrix, Ctenopharyngodon idella and Cyprinus carpio cultured under artificial feed (T1), broiler manure (T2), buffalo manure (T3), N:P:K (25:25:0) (T4) and control pond (T5) have been determined for the period of one year. The overall biomass conversion efficiencies under the influence of T2, T3, and T4 were statistically similar. However, the best (0.40) efficiency was determined under feed supplement-ation (T1).

• 한국해양생명과학회지
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• 제2권2호
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• pp.49-55
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• 2017

Four chemical treatments with hydrogen peroxide (H₂O₂), copper sulfate (CuSO₄), potassium permanganate (KMnO₄) and chlorine (Cl₂) were applied to the effluent pond water of a hybrid striped bass saltwater recirculating aquaculture system to compare their oxidation power. Four chemicals were applied at concentrations of 0 (control), 1, 5, 10 and 20 mg/l. An additional concentration of 40 mg/l was included in the chlorine treatment. Water samples from four hybrid striped bass ponds were tested with KMnO₄ and Cl₂. H₂O₂ did not reduce any of BOD, COD and chlorophyll-a, and copper sulfate was only effective on chlorophyll-a for the effluent pond. Removal efficiencies for chlorophyll-a by copper sulfate were 19.2%, 37.5%, 54.2% and 74.1% dose-dependently. Potassium permanganate effectively removed the BOD, COD and chlorophyll-a. The COD removal rates in four fish ponds varied from 15.9% to 31.6% at the concentration of 10 mg/l. Interestingly, Cl₂ did not reduce the BOD and COD at all, but the BOD and COD instead increased drastically with increasing the Cl₂ concentration. The pond water with the highest initial BOD and COD values among the fish ponds tested increased by 350% in the BOD and 150% in the COD at 20 mg/l. Furthermore, Cl₂ did not significantly reduce any types of solid matter in this study, while KMnO₄ seemed to reduce some extent volatile dissolved solid in the fish pond.

• Parasites, Hosts and Diseases
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• 제38권1호
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• pp.37-39
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• 2000

Many Koreans usually eat raw pond smelts, Hypomesus olidus, in the winter. This study was performed to evaluate the infection status with trematode metacercariae in pond smelts from January 1998 through February 1999. Among 1,305 fish collected, 459 were purchased from wholesale dealers in Chinchon-gun, Chungchongbuk-do, and the rest of them were caught with a casting net in Soyangho (Lake), Taehoman (Bay) and Paekkokchosuchi(Pond). Seven species of trematode metacercariae including two unidentified ones were detected from 1,305 pond smelts. The number of detected trematode metacercariae according to the species are as follow: Clonorchis sinensis 8, Holostephanus nipponicus 7, Cyathocotvle orientalis 24, DipLostomum sp. 14, and Metorchis orientalis 7. From the above results, it was confirmed that H. olidus plays a role as the second intermediate host of some kinds of trematode including C. sinensis in Korea. Our report shows possible clonorchiasis caused by eating raw pond smelts.

• Toxicological Research
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• 제33권2호
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• pp.119-124
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• 2017

Hexavalent chromium is a bio accumulative toxic metal in water and fish. It enters aquaculture ponds mainly through anthropogenic sources. Hexavalent chromium concentrations and its effects on the morphology and behavior of Clarias gariepinus were investigated from four aquaculture ponds for 12 weeks. Chromium was measured using diphenyl carbohdrazide method; alkalinity and hardness were measured using colometric method and analyzed with Bench Photometer. Temperature and pH were measured using pH/EC/TDS/Temp combined tester. Temporal and spatial replications of samples were done with triplicates morphological and behavioural effects of the metal on fish were observed visually. Chromium ranged from no detection to 0.05 mg/L, alkalinity 105 to 245 mg/L, hardness 80 to 165 mg/L, pH 6.35 to 8.03 and temperature 29.1 to $35.9^{\circ}C$. Trend in the chromium concentrations in the ponds is natural > earthen > concrete > collapsible. There was a significant difference (P < 0.05) in chromium, alkalinity, water hardness, pH and temperature among the four ponds. Significant positive correlation also existed between alkalinity, water hardness, pH, with chromium. Morphological and behavioural changes observed in the fish include irregular swimming, frequent coming to the surface, dark body colouration, mucous secretion on the body, erosion of gill epithelium, fin disintegration, abdominal distension and lethargy. High chromium concentration in natural pond was due to anthropogenic run-off of materials in to the pond. Acidic pH, low alkalinity, low water hardness also contributed to the high chromium concentration. Morphological and behavioural changes observed were attributed to the high concentrations, toxicity and bio accumulative effect of the metal. Toxicity of chromium to fish in aquaculture could threaten food security. Watershed best management practices and remediation could be adopted to reduce the effects of toxicity of chromium on pond water quality, fish flesh quality and fish welfare.