Responsibility
Cage design, placement affect water quality
Farm cages should be sited where water quality is good and water velocity is adequate. The size, shape and position of cages should be selected to favor rapid flushing.
Responsibility
Erosion, sedimentation in earthen aquaculture ponds
The control of external inputs of suspended soil particles to ponds and internal erosion of embankments and bottoms should begin at the design and construction stage.
Responsibility
Lake, reservoir characteristics affect cage culture potential
Culture cages should be installed in areas with good water circulation and not placed in embayments with narrow openings or very shallow water.
Responsibility
Pond fertilization reevaluated
Although higher rates have been promoted, pond fertilization ratios of 2:1 or 1:1 nitrogen to phosphorus should be maintained in older ponds for food fish production.
Responsibility
Examining water temperature in aquaculture
Water temperature is a key water quality variable in aquaculture because it influences other variables, defines growing seasons and dictates what species can be grown at a particular location.
Responsibility
Aquaculture ponds hold carbon
Although 16.6 million metric tons of carbon are annually buried in aquaculture ponds, estimated carbon emissions for culture species have approached several metric tons of carbon per metric ton of aquaculture product.
Responsibility
Dissolved oxygen concentrations in pond aquaculture
Various studies suggest that maintaining minimum daily dissolved oxygen concentrations above 3 mg/L in channel catfish and penaeid shrimp ponds assures better feed consumption and growth.
Responsibility
Oxygen demand of aquaculture feed
The oxygen demand of feed represents the dissolved oxygen removed by the respiration of culture animals, microbial decomposition of uneaten feed and feces, and oxidation of ammonia nitrogen by nitrifying bacteria.
Responsibility
Carbon-nitrogen ratio management
Carbon-nitrogen (C:N) ratio is an important variable related to soil fertility. Intensive ponds have lower C:N ratios, while higher ratios are found in extensive ponds and those constructed in organic soil.
Responsibility
Trace metals toxic at high concentrations
Excessive concentrations of trace metals, especially copper, are toxic to phytoplankton and other aquatic plants. The ionic forms of trace metals are toxic to fish and other aquatic animals, but soluble, chelated trace metals are relatively non-toxic.
Responsibility
Calculating chemical treatments for aquaculture production
In calculating chemical treatments to apply to ponds, one must adjust for the percentage of the active ingredients in products. Adjustments for both active ingredient content and specific gravity must be made for liquid products.
Responsibility
Assessing, reducing pond seepage
Ponds constructed on sandy or permeable soils are most likely to have high seepage rates. Ponds built in any soil can seep if improperlty constructed.
Responsibility
Phytoplankton in aquaculture ponds
Aquaculture ponds typically have ideal conditions for the growth of various species of phytoplankton. Green algae are considered most desirable in freshwater ponds.
Responsibility
Chlorine an effective disinfectant in aquaculture
Ponds should be fertilized a few days after chlorine application to encourage the regrowth of natural food organisms before introducing postlarvae.
Responsibility
Pond bottom soil analyses
Limit pond soil analyses to soil particle size for use in pond construction decisions, initial analysis of total sulfur, occasional analyses of total nitrogen, and routine analyses of pH and soil organic carbon.
Responsibility
Direct energy use in channel catfish production
The direct energy input values for aquaculture include energy used in constructing facilities, producing seedstock and feed, powering mechanical aerators, applying feed and harvesting and processing culture animals.