Responsibility
Settling basin design, operation
To design a settling basin, know the size distribution of particles, estimated rate of inflow and determination of the smallest particle size to be removed.
Responsibility
Evaporation affected by sunlight, temperature, wind
Evaporation of water from ponds is influenced by solar radiation, air and water temperature, and wind velocity. Control of aquatic plants can yield some reduction.
Responsibility
Assessing groundwater quality in aquaculture
Those interested in using groundwater for aquaculture should perform a thorough chemical analysis of the water. Several problems related to groundwater use in hatcheries and holding or transport vessels can be alleviated by degassing or aeration.
Responsibility
The Shrimp Book: Shrimp pond soil and water quality management
Proper site selection, consideration of soil properties and careful earthwork construction at shrimp farms are essential. Prevention of erosion protects farm infrastructure and reduces sediment accumulation in ponds.
Health & Welfare
Dissolved oxygen requirements in aquatic animal respiration
Although carbon dioxide is not highly toxic, high levels in the blood have many negative physiological consequences. As carbon dioxide increases, higher dissolved oxygen tension is necessary to load hemoglobin with oxygen.
Responsibility
Sludge management at pangasius farm cuts discharges
In modifying its infrastructure and related pond management, QVD Aquaculture uses floating water plants to remove nitrogen and phosphorus from the discharge water. Sludge pens capture sludge at ponds for later reuse.
Responsibility
Organic matter for pond fertilizer
Animal manures, grasses and other organic matter have been widely used as fertilizers in aquaculture ponds. The fertilizers decompose and release nutrients that promote the growth of phytoplankton and enhance the base of the food web.
Responsibility
Liming materials for aquaculture
Liming materials neutralize acidity and increase pH in pond bottom soil and water. They also react with carbon dioxide to form bicarbonate and release calcium and magnesium, increasing both alkalinity and hardness concentrations in water.
Responsibility
Reactions between pond bottom soil, water
Alkalinity and acidity in pond water and soil interact and can result in unhealthy culture conditions. Ion exchange occurs between soil and water until an equilibrium is reached.
Aquafeeds
Multiple methods for phytoplankton assessment
The simplest tool for assessing phytoplankton abundance in aquaculture ponds is the Secchi disk. An electronic turbidimeter can be used to measure the amount of light scattered by a water sample.
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
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
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.