1. Using aquatic plants to remove nutrients from aquaculture wastewater

2. How does aquaculture introduce nitrogen into the environment? Fish feeds contain nitrogen compounds large amounts of waste

3. Mechanisms to reduce nitrogen Traditional separation machinery settling ponds Constructed wetlands hydroponics

5. Case Studies Lin et al. (2003) ammonia 57%, nitrite 90%, nitrate 68%

6. Mississippi State University Ammonia 63% Nitrite 97% Nitrate 80%

7. Giant Salvinia (Salvinia molesta)

8. Experimental Design 4 aquaria all containing 30g tilapia 2 of the 4 aquaria containing Giant Salvinia water quality parameters (ammonia, nitrite, nitrate) measured weekly difference in nitrogen levels between tanks with aquatic plants and those without?

12. Conclusions/Experimental modifications Salvinia may be able to effect nitrogen at very low concentrations No effect at higher concentrations Questionable for use in aquaculture Light for Salvinia replications extend length of experiment

13. References Posadas, B.C. 2003. Use of constructed wetlands to improve water quality in finfish production. Mississippi State University. http://www.msstate.edu/dept/crec/cwres.htmlhttp://www.msstate.edu/dept/crec/cwres.html Lin, Y-F., Jing, S-R., Lee, D-Y. 2003. The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture. Environmental Pollution. 123: 107- 113. Seawright, D., Stickney, R., Walker, R. 1998. Nutrient dynamics in integrated aquaculture-hydroponics systems. Aquaculture. 160: 215-237 Photos Michael, J. H. Jr. 2003. Nutrients in salmon hatchery wastewater and its removal through the use of a wetland constructed to treat off-line settling pond effluent. Aquaculture. 226: 213-225 Tilapia: www.sun.ac.za/kie/unistel/ aquaculture/aquastel/ Catfish: www.fish2go.com/info6.htm Constructed wetland: http://www.msstate.edu/dept/crec/cwres.html http://www.msstate.edu/dept/crec/cwres.html Shrimp: whyfiles.org/025chem_weap/ 7.html Aquaponics(1): http://www.hamburger-umweltinst.org/biomass/mnlwide/img33.gif Aquaponics (2): www.aquaranch.com/ aquapon.html Salvinia: http://www.wapms.org/images/salvinia2.jpg