The document discusses different aquaculture systems and components of recirculating tank systems. It describes cage, raceway, and pond systems as well as recirculating tanks. Recirculating tank systems use the least amount of water and allow for close temperature control. They consist of a main tank that holds fish and circulates water, biofilters where beneficial bacteria convert fish waste into less toxic forms, and a sediment tank where solids settle out. Aerators and equipment like seines are also discussed.

1. Aquaculture Systems Current Events: A vaccine for Ich

2. Types of systems Cage Raceway Pond Recirculating Tanks

3. Cage Can move cage to fresh water Fish can escape Fish can be stolen/released Movie

4. Raceway Need constant flow of water Generally built parallel to rivers Necessary for trout High water quality

5. Pond Most common method Large scale production Lowest maintenance

6. Recirculating tanks Uses least amount of water Best Temperature control Lowest water quality

7. Recirculating Tanks Main Tank Bio Filters Sediment Tank Pumps Water in/out control

8. Main Tank Holds fish Creates circular water pattern Collects from the bottom Removes Sediment/waste

9. Biofilter Plastic substrate that bacteria can cling to. Bacteria convert toxic ammonia (NH 3 ) in fish waste to nitrite (NO 2 ) and then nitrate (NO 3 ) which is least toxic.

10. Biofilter Bacteria ( Nitrosomonas & Nitrobacter ) cling to plastic discs Aerobic Bacteria Bacteria control the Ammonia Takes 2-4 weeks for colonization Ammonia ->Nitrite ->Nitrate NH 3 & NH 4 + ->NO 2 ->NO 3 Most toxic -> Least toxic

11. Sediment Tank Has a cone shaped bottom Non-soluble solids settle out Soluble solids – give the water a brown color – need special filters

12. Sand filter Removes solids Sand clogs quickly Must backwash daily Residue build-up No longer functional

13. Aquaculture Tanks

14. Aerators Keep the water circulating Keep oxygen in the water so fish do not suffocate.

15. Equipment Seines – nets with predetermined opening sizes to catch or hold only fish larger than a specific size

16. Shrimp Harvest Video