Tag Claude E. Boyd

Iron is the fourth most abundant element in the earth’s crust, but occurs at very low concentrations in surface waters and oceans. It is an essential element for many organisms as part of many enzymes, and also has an important role in plant photosynthesis. 

Los programas de certificación actualmente son la mejor herramienta para asegurar que los productos acuícolas se producen de manera responsable. Sin embargo, estos programas pueden ser sobrecargados por muchos requisitos superfluos y su simplificación, centrándose principalmente en las cuestiones principales, sería una gran mejora. 

Certification programs presently are the best tool to assure that aquaculture products are responsibly produced. But these programs can be burdened by many superfluous requirements and their simplification by focusing primarily on the major issues would be a great improvement. 

Proper monitoring of water quality in aquaculture production systems is critical to enable appropriate and timely management decisions. It requires reliable equipment, trained technicians that follow instructions and apply quality control measures, proper reagents and calibrated equipment, and appropriately collected water samples that are promptly analyzed. 

Los estanques acuícolas acumulan materia orgánica de fertilizantes orgánicos, restos de micro-organismos producidos dentro del estanque, las heces de los animales criados y el alimento no-consumido. Claude E. Boyd, Ph.D., detalla las principales prácticas de gestión de la materia orgánica, y dice que frecuentemente la acumulación de materia orgánica no es tan grande como se creía. 

Aquaculture ponds accumulate organic matter from organic fertilizer, remains of microorganisms produced within the pond, feces of the culture animals and uneaten feed. Claude E. Boyd, Ph.D., details the leading organic matter management practices, and says that the accumulation of organic matter is often not as great as believed. 

Phytoplanktonic organisms, or microalgae, are very abundant in aquaculture ponds and have critical roles in these ecosystems, significantly influencing overall pond ecology and water quality. Proper management of phytoplankton populations is essential for successful aquaculture pond production. 

Although relatively expensive, mechanical aeration increases production. Asian-style paddlewheel aerators are widely used but are inefficient. Testing has led to more efficient designs that are now widely used in U.S. catfish and shrimp ponds. 

Aquatic plants and animals get the essential nutrients calcium and magnesium from water and food. Calcium concentrations impact the hydration and development of eggs in a hatchery, where calcium carbonate precipitation can be troublesome. 

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. 

A few anions and cations, and un-dissociated silicic acid represent the largest fraction of dissolved inorganic solids in water. The total concentration of ions is called the salinity. The total dissolved-solids concentration usually is roughly equal to salinity in freshwater. Unlike seawater, freshwater varies greatly in salinity and proportions of individual ions. Calcium and bicarbonate are dominant ions in river water, but sodium and chloride are dominant in seawater. Water contains many other inorganic substances, as well as many trace elements. 

In life cycle analysis of aquaculture, there is a danger of the entire array of embodied resources and impacts being assigned to the production facility. Producers have no control over the inefficiencies or impacts associated with feed production, but can help lessen resource use through good management practices. 

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. 

The authors believe that dry-out periods likely destroy most organisms in pond bottoms, and liming of the entire bottom area should be done only to neutralize soil acidity and increase pH for organic matter decomposition by soil microorganisms. 

The main pond bottom soil management practices used in semi-intensive culture are pond dry-out and liming between crops. These practices accelerate organic matter decomposition, neutralize soil acidity and destroy unwanted organisms.