Tag water quality

Several large shrimp farms in Latin America, originally built to operate using significant, flow-through water exchange with the surrounding environment, have been retrofitted to a recirculating operation mode. This modification provides numerous benefits, including improved biosecurity. 

Confusion can result because of differences in units (dimensions) used to report water quality variables, which can lead to faulty assessments. Professor Claude Boyd discusses issues related to units of measure for some common water quality values in aquaculture. 

Wisconsin State Rep. Mary Felzkowski and others are championing aquaculture to grow food production in the state, with a keen interest in recirculating aquaculture systems (RAS). 

Phytoplankton has several important effects on water quality, including removing ammonia nitrogen from water and absorbing nutrients from the water for its growth. Abundance of blue-green algae tends to increase as nutrient inputs in aquafeeds or fertilizers increase. 

Shrimp nursery systems offer the shrimp industry an important opportunity to increase profits, by helping produce strong, healthy and uniform juveniles with significant potential for compensatory growth after their transfer for final pond grow-out. Biofloc technology and water quality are critical components of shrimp nursery systems. 

It is one of the most commonly measured water quality variables in aquaculture, and probably the most misunderstood water quality variable in aquaculture. The pH levels in water have a propensity to change rapidly, but this is a natural phenomenon that often has little consequences and not much can be done to avoid it. 

Attention to pH, a numeric scale used to specify the acid or alkaline condition of an aqueous solution, is very important. Reducing biomass and feeding rates together with phytoplankton control and liming can often keep pH at desirable values. 

Amigos, colegas y ex alumnos del Profesor Claude E. Boyd, Ph.D. de muchos años de la Universidad de Auburn, no esperan que el nativo de Mississippi vaya a reducir su paso, a pesar del callado anuncio de su retiro a principios de este mes. La carrera de investigador del veterano de 50 años ha sido verdaderamente extraordinaria. 

Friends, colleagues and former students of longtime Auburn University Professor Claude E. Boyd, Ph.D., don’t expect the Mississippi native to slow down, despite the quiet announcement of his retirement earlier this month. The 50-year veteran researcher’s career has been truly extraordinary. 

Uneaten or undigested feed and their metabolic byproducts contribute to declines of water quality in aquaculture systems. Accordingly, feed and feeding techniques require continuous review. Reducing overfeeding is an important opportunity for improving feed conversion ratios. 

Zero-exchange biofloc systems allow elevated stocking densities and production, but also require more dissolved oxygen and thorough water circulation. A new type of air injector uses only a centrifugal pump to recirculate water while naturally aspirating ambient air. 

A study found that feed for salmon and trout had higher organic carbon concentrations than did catfish, shrimp and tilapia feeds. Nitrogen and phosphorus concentrations were similar among salmon, trout and shrimp feeds, and higher than those in catfish and tilapia feeds. 

To start a biofilter together with a source of nitrifying bacteria, you must provide the conditions that will encourage the growth of the bacteria. The basic process requires initial preparation of water chemistry, adjustment of alkalinity to support bacterial growth and the addition of ammonia. 

The creation and application of reference tables for acceptable concentration ranges of physical and chemical water quality variables for culture organisms would be challenging due to the differing tolerances found among the many farmed species. 

Acid rain typically does not heavily affect aquaculture operations, and application of agricultural limestone can buffer water against the impacts of acid rain at facilities that use stream water.