Dissolved salts in water for inland, low-salinity shrimp culture
Low-salinity shrimp culture is an important activity in Thailand. Ponds contain water of 2 to 5 ppt salinity, mixing brine solution from coastal seawater with freshwater.
Understanding pond pH
Natural waters uninfluenced by high biological activity seldom have pH above 8.5, but in fish or shrimp culture, pond pH levels can rise to 9 or higher.
Denitrification in recirculating aquaculture systems: Comparison of aquatic plants
Denitrification by anaerobic bacteria can remove nitrates from RAS, but the operation requires anaerobic conditions and the addition of carbon sources.
Nitrification rates in fluidized-bed filters
Study evaluates nitrification rates of three fluidized-bed filters, finding no significant changes in fluidization level as biofilm accumulated or was sheared off.
No single solution for effluent management
Where aquaculture is key to food or employment, policies regarding effluent management should be flexible to address various species, systems and environments.
Anion-cation balance in water
The ionic composition of inland well water can vary from suitable to toxic to cultured animals. Reliable data on concentrations of major cations (calcium, magnesium, potassium, and sodium) and major anions (bicarbonate, sulfate, and chloride) is therefore important in the management of waters for inland shrimp farming.
Specific conductance: An alternative salinity measurement
Water's ability to conduct electricity increases with the total concentration of dissolved ions. Measuring conductivity helps estimate salt content of water.
Partitioned aquaculture systems
Partitioned aquaculture system for catfish and co-culture of tilapia can achieve catfish yields up to four times higher than conventional pond culture.
Model for managing organic sediment in aquaculture ponds
With increasing intensification of pond aquaculture, management of sediment like organic matter is becoming an important concern for pond managers.
Cage-cum-pond: Integrated aquaculture systems recycle wastes
Integrated aquaculture systems comprise large fish cultured intensively in cages and small fish cultured semi-intensively in the surrounding pond water.
Shrimp production systems with low/no water exchange
Research in a culture system without water exchange indicated that biological performance of postlarvae was similar.
Nitrogen and phosphorus loads vary by system
Adding nitrogen and phosphorus to natural waters can cause eutrophication. Discharge of these nutrients from aquaculture operations is under U.S. government evaluation.
Effects of sand, sediment, vertical surfaces on intensive shrimp production
In intensive shrimp-culture systems, sand, sediment and other surface areas can have both positive and negative effects on shrimp production.
Biological lamella sedimentation
Sedimentation is a useful technique to manage aquaculture wastewater because a high proportion of suspended solids have a high sinking rate.
Water quality standards: Dissolved Oxygen
Dissolved oxygen concentration is perhaps the most important variable influencing the well-being of fish, shrimp and other aquatic life.
Sediment accumulation in earthen shrimp ponds
Shrimp aquaculture farm managers suspect pond bottom degradation and sediment accumulation as possible causes for production decreases.