Salt reduces the effects of stress in shad, especially during transport and in conserving energy for physiological emergency purposes, and in countering the electrolytes disturbances associated with stress-elevated adrenaline and cortisol levels.
Adding salt properly in holding and transportation tanks will help treat health problems and water quality problems.
Use of Salt in Transporting and Handling Shad.
When Shad are transported and handled, they are forced to expend extra energy for osmoregulation (water balance) unless salt is added to the transport water.
Shad tend to over-hydrate when held in fresh water during transporting, due to the influx of water across the gills and into the bloodstream. To compensate for this water imbalance, fish pump excess water back across their gills.
Increasing the salt concentration of the transport water inhibits this process, making depletion of energy reserves less likely.
Short-term exposure to a high concentration of salt produces an
Salt helps shad maintain their proper blood chemistry while under stress.
Sodium chloride (NaCl) is approved for aquaculture use as an "osmoregulatory enhancer." Salt can change the osmoregulatory balance (water balance) of aquatic organisms. It can sometimes be used effectively to control external parasitic protozoans by placing them in a condition of severe osmoregulatory shock.
Salt is used as a 0.5% to 1.0% concentration in water as an indefinite (long-term) treatment or as a 3% concentration in water for 1-10 minutes. Care must be exercised to avoid overtreatment which will place the fish in the same condition of osmoregulatory shock.
SALT Concentrations for holding Shad in Bait Tanks.
The effects of salt on fish are determined both by salt concentration and duration of exposure. Seawater contains 3 percent salt by weight; this is equivalent to 30 parts per thousand (ppt) or 30,000 parts per million (ppm). Some parasitic infestations of freshwater fish may be effectively eliminated by dipping fish in a seawater solution for 30 seconds to 10 minutes, depending on the species. Weaker solutions containing 0.5 to 1.0 percent salt may be used as a bath for several hours to eliminate some freshwater parasites. Concentrations of 0.1 to 0.3 percent may be used to enhance mucus production and osmoregulation in freshwater fish during handling and transport. Very weak salt treatments, measured in ppm, may be used to control methemoglobinemia in some freshwater fish species.
Freshwater fish use cells in their gills to take in the salts that they lose to the water, which helps keep their bodies salty. Adding salt to the water when fish are stressed means that they don't lose as much salt from their bodies. The principle is much the same as a saline drip for hospital patients.
Some fish keepers and salt manufacturers recommend adding salt as a routine permanent treatment. Also using sea salt which is "(98% NaCl ) + 80 other elements (2%) is my choice vs pure salt (sodium chloride 99.9% or refined salt which contain only 0.1 - 0.5% other elements
Shad stress out when caught, handled or being chased or transported.
A general recipe may be found in Spotte, (1970).
The Bulk density of salt approximate (dry, ASTM D 632 gradation)
1.154 (72 lb/ft3)
Conversions of salt dosages
1 pound (lb.) = 454 grams (g)
Once the volume is calculated in cubic feet, the gallons are determined using these conversions:
1 ft = 7.48 gallons
Calculating tank volume is an important step to effective salt
application. Measurements used to determine volume are usually in feet
Finding Volume of a square or rectangular raceway, tank or pond.
A rectangular tank is 12 feet (ft.) long, 3 ft. wide and 3
Vol. = 12 ft. x 3 ft. x 3 ft.
Finding Volume of a round tank which is recommended for keeping shad.
A round tank is 12 ft. in diameter and 4.5 ft. deep.
(Radius = 0.5 x diameter)
The most commonly used units of measure in aquaculture is the
part per million, commonly referred to as ppm.
How much salt is needed to make a 2% solution in a round tank ?
salt needed (g) = 0.00378 g/gal. x 3,805.1 gal. x 20,000 = 287,663g or 633.6 lbs. (287,663g = 633.6 lbs.) 454g/lb.
How much salt is needed to make a 0.5% solution in a 100-gal. transport tank?
0.5% = 5,000 ppm
Calculating Tank Volume for adding Salt .