1. Recycle Aquaculture for the Future: a Muddy Crystal Ball BY Dallas E. Weaver, Ph.D. Scientific Hatcheries Huntington Beach, Ca

2. Look at the Past 30 years ago 30 years ago –Analysis of a recycle aquaculture proposal »Very secret, proprietary technology »Put the facilities near the market »Excellent financial projections –Central economic issue was waste removal »If this technology could remove waste at ppm levels at the stated cost, why not go into the waste treatment business ( an N billion dollar existing business -- N is a big number) »Economics only work for high value products.

3. Vision of the Future Seafood demand increasing Seafood demand increasing Wild catch will not increase Wild catch will not increase Aquaculture will continue to grow Aquaculture will continue to grow –Land based »Limited by water supply (quantity & quality) »Environmental considerations –Marine Based »Near shore protected areas limited »Offshore is unlimited.

4. Vision of the Future Globalization will continue Globalization will continue Land, Energy and Labor in the US will be relatively expensive Land, Energy and Labor in the US will be relatively expensive The US will still have seasons The US will still have seasons Niche markets will be limited in size Niche markets will be limited in size –Can be good for an individual but not a “real industry”

5. System Overview Feed Product Refractory Organic - Sludge Waste Soluble Refractory Organic - COD Algae Microbiological Ecology Sun Water Chemistry Live Feed

6. Approaches to Waste Treatment System Design Breakdown system Breakdown system –Conventional recycle systems »Remove solid waste (screens, bead filters, settling areas, etc.) »Biologically oxidize soluble materials (nitrification, biofilters, etc.) »Gas transfer (add Oxygen, remove CO2) –Suspended culture systems »High SS limits specie »Future controlled microbiology

7. Scientific Hatcheries Process Flow Tanks Bead Filter Fluidized Bed Biofilter Packed Column Return Flow Sludge Flow Denitrification

8. Approaches to Recycle System Design Buildup system Buildup system –Algae Based system »Waste + sunlight = algae Algae to waste -- bottom sludge, environment Algae to waste -- bottom sludge, environment Algae to food chain to supplemental feed Algae to food chain to supplemental feed Algae to feed -- recycle nutrients Algae to feed -- recycle nutrients –PAS type systems required for stability –Control over the ecology »Limited by energy density 10 gm of Carbon/M2 day 10 gm of Carbon/M2 day

9. Approaches to Waste Treatment System Design Buildup system Buildup system –Bacterial Based system - Heterotrophic system »Waste + carbohydrate (lipid) = biomass Bacterial biomass to waste -- bottom sludge, environment Bacterial biomass to waste -- bottom sludge, environment Bacterial biomass to food chain to supplemental feed Bacterial biomass to food chain to supplemental feed –C/N ratio control systems – Belize type shrimp system Bacterial biomass to feed -- recycle nutrients Bacterial biomass to feed -- recycle nutrients –PAS type systems required for stability –Control over the ecology and flocculation required »Limited by gas/liquid mass transfer and mixing

10. Economic Consideration All systems and approaches can work with the real question being which systems with which species at what prices can be profitable. All systems and approaches can work with the real question being which systems with which species at what prices can be profitable. Waste treatment cost are related to the feed inputs and can be viewed in terms of $/Kg of feed. Waste treatment cost are related to the feed inputs and can be viewed in terms of $/Kg of feed. Approaching the economics of alternatives Approaching the economics of alternatives

11. Recycle Systems: Some basic concepts Cumulative Feed Burden (CFB) kg of feed/M3 of discharge liquids (kg/m3 or ppt). Cumulative Feed Burden (CFB) kg of feed/M3 of discharge liquids (kg/m3 or ppt). Loop Strength (LS) gm feed/ M3 of recycle flow ( in mg/l) Loop Strength (LS) gm feed/ M3 of recycle flow ( in mg/l) Area Loading (AL) gm feed/ M2 per day Area Loading (AL) gm feed/ M2 per day

14. Season and Area Loading 100 kg/Ha Day

15. What can be profitable with existing technology? Niche Markets ( > $10/kg) Niche Markets ( > $10/kg) –At a high enough price, all approaches work High Volume Markets -- low prices High Volume Markets -- low prices –Pond culture systems –Free water flow though system (agriculture water or ocean net pens) –PAS type systems using algae or marsh treatment systems

16. What can work in the Future? Ecological control systems Ecological control systems

18. Economic Conclusions Recycle systems are expensive Recycle systems are expensive –Designs are based on Kg/day of feed input –But minimal environmental impact As an Extension Agent As an Extension Agent –Recycle Aquaculture is high risk, capital intensive, knowledge intensive, hard work type of business. Amateurs do not succeed. In the Future In the Future –Control over micro-biological ecology may decrease capital and operating cost.