Health & Welfare

How salinity levels impact EHP infection rates in Pacific white shrimp

An EHP infection can occur at a salinity as low as 2 ppt but the prevalence and the severity of the EHP infection is higher at 30 ppt salinity. 

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Water composition: Dissolved inorganic solids
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Water composition: Dissolved inorganic solids

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. 

TAN, other water quality factors affect nitrification rates in biofilters
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TAN, other water quality factors affect nitrification rates in biofilters

An important criterion when studying biofilters is the conversion rate of total ammonia nitrogen (TAN) to nitrate-nitrogen in production water. Although nitrification rates have been based on media surface areas, they do not always reflect the actual nitrification achieved. Volumetric TAN conversion rate is a direct measure based on filter volume. 

Salinity tolerance of Gulf corvina, prospective aquaculture species
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Health & Welfare

Salinity tolerance of Gulf corvina, prospective aquaculture species

After six weeks of experimental culture, comparable growth and survival were recorded in juvenile Gulf corvina raised at salinities of 5, 15, 25 or 35 ppt. Coupled with stable plasma osmolality values observed in fish at the varied salinities, these results confirmed the euryhaline nature of this species, a trait that could enhance its status as a candidate for aquaculture.