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Sulfides alter aquaculture pond pH, can be toxic
https://www.globalseafood.org/advocate/sulfides-alter-aquaculture-pond-ph-can-be-toxic/…this. The ionic forms of sulfide are not as toxic as hydrogen sulfide, whose concentration can be estimated for the appropriate pH and water temperature (Table 1). Boyd, Hydrogen sulfide…
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Effluent effects from aquaculture ponds
https://www.globalseafood.org/advocate/effluent-effects-from-aquaculture-ponds/…larger amounts of pollutants than those in developing countries. Boyd, Typical waste water constituent data, Table 1 ParameterDeveloped Nations RangeDeveloped Nations MeanDeveloped Nations RangeDeveloped Nations Mean Biochemical oxygen demand 49.00-120.00…
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Study identifies maximum holding times for water samples
https://www.globalseafood.org/advocate/study-identifies-maximum-holding-times-for-water-samples/…hardness, which were stable for 72 hours, likely could be held longer, but samples should always be analyzed promptly. Boyd, Recommended holding times, Table 1 VariableTime (hours) pH Analyze on…
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Copper treatments control phytoplankton
https://www.globalseafood.org/advocate/copper-treatments-control-phytoplankton/…concentration to control phytoplankton. Boyd, Concentration of cupric ions, Table 1 pHCupric Ion Concentration (mg/l) 5 28 6 2.8 7 0.028 8 0.00028 9 0.0000028 Table 1. Concentration of cupric…
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Measuring water flow
https://www.globalseafood.org/advocate/measuring-water-flow/…the appropriate coefficient from Table 1. Boyd, Velocity coefficients for the float method, Table 1 Average Flow Depth (m)Coefficient 0.25 0.64 0.50 0.67 0.75 0.70 1.00 0.71 1.50 0.74 2.00…
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Secchi disk visibility: Correct measurement, interpretation
https://www.globalseafood.org/advocate/secchi-disk-visibility-correct-measurement-interpretation/…is greater, the criteria may not apply. However, the Secchi disk visibility necessary to shade pond bottoms and prevent underwater weed infestations is similar almost everywhere. Boyd, Interpretation of Secchi…
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Organic matter in pond bottom sediment
https://www.globalseafood.org/advocate/organic-matter-in-pond-bottom-sediment/…shows the classification of bottom soil organic matter concentrations for samples taken at this time. Boyd, Classification of bottom soil, Table 1 Organic Carbon (%)Comment > 15 purposes Organic soil,…
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Zeolite ineffective as pond treatment
https://www.globalseafood.org/advocate/zeolite-ineffective-as-pond-treatment/…than the total capacity of the mineral to absorb cations. Boyd, Table 1 SalinityAmmonia Removal (g/kg zeolite) 0.1 ppt (tap water) 9.0 4 ppt 0.12 8 ppt 0.10 16 ppt…
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Specific conductance: An alternative salinity measurement
https://www.globalseafood.org/advocate/specific-conductance-an-alternative-salinity-measurement/…specific conductance is illustrated in Table 1. Boyd, Concentration versus specific conductance, Table 1 Potassium Chloride Normality Potassium Chloride mg/lSpecific Conductance (µmhos/cm) 0.0 0.0 0.0 0.0001 7.5 14.9 0.0005 37.3…
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Land and water use issues in aquaculture
https://www.globalseafood.org/advocate/land-and-water-use-issues-in-aquaculture/…equal total water use. Aquaculture production units can be classified according to their requirements for land and water as shown in Table 1. Boyd, Water use in aquaculture production systems,…
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Water quality standards: pH
https://www.globalseafood.org/advocate/water-quality-standards-ph/…range 7 to 8.5. Boyd, Effect of pH on aquatic organisms, Table 1 pHResponse 4 Acid death point 4-5 Acid stress, no reproduction, slow growth 5-6 Acid stress, reproduction may…
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Water quality standards: Total phosphorus
https://www.globalseafood.org/advocate/water-quality-standards-total-phosphorus/…form. Boyd, Typical inputs and outputs of phosphorus, Table 1 Phosphorus InputsPhosphorus Outputs Feed 90% Shrimp 25% Inflowing Water 10% Soil Uptake 65% Effluent 10% Table 1: Typical inputs and…
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Water quality standards: Total Ammonia Nitrogen
https://www.globalseafood.org/advocate/water-quality-standards-total-ammonia-nitrogen/…ponds at harvest (Table 1). Boyd, Typical inputs and outputs of nitrogen, Table 1 InputsInputsOutputsOutputs Feed and fertilizer 90% Shrimp harvest 25% Water supply and nitrogen fixation 10% Denitrification 12%…
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Formulating standards for effluent management
https://www.globalseafood.org/advocate/formulating-standards-for-effluent-management/…regarding permissible concentrations of selected water quality variables. Examples of concentration- based criteria in a water quality standard are noted in Table 1 below. Boyd, Concentration-based criteria in a water…
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Water use in aquaculture
https://www.globalseafood.org/advocate/water-use-in-aquaculture/…more efficiently than other terrestrial, irrigated agriculture, even in arid climates. Boyd, water use, Table 1 ClimateInflow (mm/yr) Wet 900 Table 1. Inflow necessary to maintain water levels in levee…
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Farm effluent during draining for harvest
https://www.globalseafood.org/advocate/farm-effluent-during-draining-for-harvest/…exchange. Boyd, Amount of effluent from different water exchange rates, Table 1 Average Daily Water Exchange (% Pond Volume)Exchange Effluent Volume (m3/ha per Crop) 2 24,000 5 60,000 10 120,000…
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Water composition and shrimp pond management
https://www.globalseafood.org/advocate/water-composition-and-shrimp-pond-management/…concentration of 142 milligrams per literis equivalent to a total alkalinity of 116 milligrams per liter. Boyd, Average concentrations of major dissolved substances, Table 1 SubstanceSeawater (mg/l)River Water (mg/l) Chloride…
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Round peg in a square hole: Aeration in a square shrimp pond
https://www.globalseafood.org/advocate/round-peg-in-a-square-hole-aeration-in-a-square-shrimp-pond/…distribute and control the flow within a pond, and there may be places where flow is excessive and harmful (Boyd 1995). Shear stress The quality of the circulation in a…