Bell Work

1. Bell Work What type of aquaculture system do we have outside?

2. Types of Aquaculture Systems Area: Animal Science Unit: Aquaculture Lesson #7

3. Objectives • To identify the types of aquaculture systems. • To identify the parts of an aquaculture system. • To design an aquaculture system.

4. What are the types of aquaculture systems? • There are 5 types of aquaculture systems • Pond Culture • Canal Culture • Cage Culture • Raceway Culture • Recirculating Systems.

5. Pond Culture • Ponds are earthen enclosures that hold water. • Most common way to raise fish. • Easy design and low construction costs. • Need large areas of land.

7. Canal Culture • Irrigation canals are also used to raise fish. • In areas where water is scarce, it is good to have multiple ways to use water. • Divided into sections by nets or screens • As long as no chemicals are placed into the canals, they can be a great place to raise fish.

8. Cage Culture • Cages are floating structure designed to contain fish. • Common in large bodies of water such as lakes and oceans. • Allow water and feed to freely float through them and fish wastes to move away • Allow for easy capture of fish • Cages come in various sizes and shapes.

10. Raceway Culture • Raceways are long narrow structures where water constantly flows through. • Typically used for trout. • Allow for intensive raising of fish . • constant flow of water. • Typically raceways are setup in series. • They require 5,000-10,000 gallons of water to raise 1 pound of fish.

12. Recirculating Systems • Recirculating systems use tanks and filters to raise fish. • Tanks come in a variety of shapes, sizes, and materials. • Usually several tanks are placed together in a system. • Need 5-10 gallons of water . • Generally discharges 5% of its total system water per day.

14. What are the components of a recirculating system? • There are 3 components to a recirculating system • solids removal • biofilters • dissolved gasses.

15. Fine & Dissolved Solids Removal Carbon Dioxide Removal Air Stone Diffuser Packed Column Fish Culture Tank Aeration or Oxygenation Air Stone Diffuser Packed Column Down-Flow Contactor Nitrification Rotating Biological Contractors Packed Bed Filters Expandable Media Filters Waste Solids Removal Sedimentation Screen Filters Granular Media Filters

16. Solids Removal • Unused feed and fish waste can cause a problem to recirculating systems. • Rich in ammonia and require lots of oxygen to be broken down. • 4 types of solids removal systems • Sedimentary tanks • Screens • Sand Filter • Expandable Bed Filter

17. Sedimentary tanks • Allow for wastes to settle out of the water to the bottom of the tank. • The tank can then be drained of the solids.

18. Screens • Water passes through a series of screens. • Particles are trapped in the screen mesh. • Screen mesh gets smaller as it goes down the line. • They can then be removed and cleaned.

19. Sand Filter • Water passes through a pocket of sand, gravel, or some other media. • The sand captures particles as water is pumped through it. • Cleaned by backflushing the system. • Water is forced through in the opposite direction separating the particles from the sand.

20. Expandable Bed Filter • Water is pumped through the sand from the bottom. • A coarser media above the sand which allows for more particles to be trapped. • To clean this filter, water is forced at a higher pressure through the filter forcing particles through the material and out a drain.

21. Biofilters • Biofilters are necessary to remove ammonia and nitrites. • Tanks where fish are densely stocked, these levels will get extremely • 4 types of biofilters • Rotating Biological Contractors • Expandable Bed Filter • Fluidized Bead Filter • Packed Tower Filter or Trickle Filter

22. Rotating Biological Contractors • These filters rotate in the water allowing for water to cover the filter. • Also helps to stir and oxygenate the water.

24. Expandable Bed Filter • These filters are also good for the removal of ammonia and nitrites. • The coarse material in the filters give good surface areas for bacteria colonization. • These filters are hard to clean and are not as commonly used in small systems.

26. Fluidized Bead Filter • Here beads are constantly turned within the filter. • Tends to have the same effects as the RBC. • Beads allow for a good surface area for bacteria growth. • Movement of the beads also allows for a good exchange of gasses in the water.

28. Packed Tower Filter or Trickle Filter • Uses a stack of biofilter material • Allows water to trickle over them. • Many different designs of these types of filters.

30. Dissolved Gas Control • Oxygen, carbon dioxide, and nitrogen need to be exchanged throughout the water in order for the fish to survive. • 2 ways to do this • Surface aeration • Diffusion aerators.

31. Surface Aeration • The surface area of the water is increased. • Nozzles spray water onto the surface of the water, • Disturbs it allowing water from below to move up • Packed tower filters also do a great job for this type of aeration.

32. Diffusion Aerators • Put air into the water. • Oxygen contained in air bubbles will diffuse into the water through the surface of the bubbles. • Many small bubbles are better than a few large bubbles • Diffusion aerators also move water in the tank from the bottom to the surface.