Recycle Aquaculture for the Future: a Muddy Crystal Ball

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

2. 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. Look at the Past

3. Seafood demand increasing Wild catch will not increase 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. Vision of the Future

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

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

6. 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 Approaches to Waste Treatment System Design

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

8. Buildup system Algae Based system Waste + sunlight = algae Algae to waste -- bottom sludge, environment Algae to food chain to supplemental feed 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 Approaches to Recycle System Design

9. Buildup system Bacterial Based system - Heterotrophic system Waste + carbohydrate (lipid) = biomass Bacterial biomass to waste -- bottom sludge, environment Bacterial biomass to food chain to supplemental feed C/N ratio control systems Belize type shrimp system 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 Approaches to Waste Treatment System Design

10. 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. Approaching the economics of alternatives Economic Consideration

11. 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) Area Loading (AL) gm feed/ M2 per day Recycle Systems:Some basic concepts

14. Season and Area Loading100 kg/Ha • Day

15. Niche Markets ( > $10/kg) At a high enough price, all approaches work 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 What can be profitable with existing technology?

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

18. Recycle systems are expensive Designs are based on Kg/day of feed input But minimal environmental impact 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 Control over micro-biological ecology may decrease capital and operating cost. Economic Conclusions