Tag Claude E. Boyd

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

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. 

Culture cages should be installed in areas with good water circulation and not placed in embayments with narrow openings or very shallow water. 

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. 

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.