Recycle Aquaculture for the Future: a Muddy Crystal Ball

Recycle Aquaculture for the Recycle Aquaculture for the Future: a Muddy Crystal BallFuture: a Muddy Crystal Ball

BY

Dallas E. Weaver, Ph.D.

Scientific HatcheriesHuntington Beach, Ca

Look at the PastLook at the Past 30 years ago 30 years ago

– Analysis of a recycle aquaculture proposalAnalysis of a recycle aquaculture proposal» Very secret, proprietary technologyVery secret, proprietary technology» Put the facilities near the marketPut the facilities near the market» Excellent financial projectionsExcellent financial projections

– Central economic issue was waste removalCentral economic issue was waste removal» If this technology could remove waste at ppm levels at the If this technology could remove waste at ppm levels at the

stated cost, why not go into the waste treatment business ( stated cost, why not go into the waste treatment business ( an N billion dollar existing business -- N is a big number)an N billion dollar existing business -- N is a big number)

» Economics only work for high value products.Economics only work for high value products.

Vision of the FutureVision of the Future

Seafood demand increasingSeafood demand increasing Wild catch will not increaseWild catch will not increase Aquaculture will continue to growAquaculture will continue to grow

– Land based Land based » Limited by water supply (quantity & quality)Limited by water supply (quantity & quality)

» Environmental considerationsEnvironmental considerations

– Marine BasedMarine Based» Near shore protected areas limitedNear shore protected areas limited

» Offshore is unlimited.Offshore is unlimited.

Vision of the FutureVision of the Future

Globalization will continueGlobalization will continue Land, Energy and Labor in the US will be Land, Energy and Labor in the US will be

relatively expensiverelatively expensive The US will still have seasonsThe US will still have seasons Niche markets will be limited in sizeNiche markets will be limited in size

– Can be good for an individual but not a “real Can be good for an individual but not a “real industry”industry”

System OverviewSystem OverviewFeed

Product

Refractory Organic - Sludge Waste

Soluble Refractory Organic - COD

Algae

MicrobiologicalEcology

Sun

Water Chemistry

Live Feed

Approaches to Waste Treatment Approaches to Waste Treatment System Design System Design

Breakdown systemBreakdown system– Conventional recycle systemsConventional recycle systems

» Remove solid waste (screens, bead filters, settling areas, Remove solid waste (screens, bead filters, settling areas, etc.)etc.)

» Biologically oxidize soluble materials (nitrification, Biologically oxidize soluble materials (nitrification, biofilters, etc.)biofilters, etc.)

» Gas transfer (add Oxygen, remove CO2)Gas transfer (add Oxygen, remove CO2)

– Suspended culture systemsSuspended culture systems» High SS limits specie High SS limits specie

» Future controlled microbiologyFuture controlled microbiology

Scientific Hatcheries Scientific Hatcheries Process FlowProcess Flow

Tanks BeadFilter

FluidizedBedBiofilter

PackedColumn

Return Flow

Sludge Flow Den

itri

fica

tion

Approaches to RecycleApproaches to Recycle System Design System Design

Buildup systemBuildup system– Algae Based systemAlgae Based system

» Waste + sunlight = algaeWaste + sunlight = algae Algae to waste -- bottom sludge, environmentAlgae to waste -- bottom sludge, environment Algae to food chain to supplemental feed Algae to food chain to supplemental feed Algae to feed -- recycle nutrientsAlgae to feed -- recycle nutrients

– PAS type systems required for stabilityPAS type systems required for stability

– Control over the ecologyControl over the ecology

» Limited by energy density Limited by energy density 10 gm of Carbon/M2 day10 gm of Carbon/M2 day

Approaches to Waste Treatment Approaches to Waste Treatment System Design System Design

Buildup systemBuildup system– Bacterial Based system - Heterotrophic systemBacterial Based system - Heterotrophic system

» Waste + carbohydrate (lipid) = biomassWaste + carbohydrate (lipid) = biomass Bacterial biomass to waste -- bottom sludge, environmentBacterial biomass to waste -- bottom sludge, environment Bacterial biomass to food chain to supplemental feedBacterial biomass to food chain to supplemental feed

– C/N ratio control systemsC/N ratio control systems– Belize type shrimp systemBelize type shrimp system

Bacterial biomass to feed -- recycle nutrientsBacterial biomass to feed -- recycle nutrients– PAS type systems required for stabilityPAS type systems required for stability– Control over the ecology and flocculation requiredControl over the ecology and flocculation required

» Limited by gas/liquid mass transfer and mixingLimited by gas/liquid mass transfer and mixing

Economic ConsiderationEconomic Consideration

All systems and approaches can work with All systems and approaches can work with the real question being which systems with the real question being which systems with which species at what prices can be which species at what prices can be profitable. profitable.

Waste treatment cost are related to the feed Waste treatment cost are related to the feed inputs and can be viewed in terms of $/Kg inputs and can be viewed in terms of $/Kg of feed.of feed.

Approaching the economics of alternativesApproaching the economics of alternatives

Recycle Systems:Recycle Systems:Some basic conceptsSome basic concepts

Cumulative Feed Burden (CFB) kg of Cumulative Feed Burden (CFB) kg of feed/M3 of discharge liquids (kg/m3 or feed/M3 of discharge liquids (kg/m3 or ppt). ppt).

Loop Strength (LS) gm feed/ M3 of recycle Loop Strength (LS) gm feed/ M3 of recycle flow ( in mg/l)flow ( in mg/l)

Area Loading (AL) gm feed/ M2 per dayArea Loading (AL) gm feed/ M2 per day

CFB and water cost

$0.01

$0.10

$1.00

$10.00

$100.00

0.1 1 10 100

CFB kg/M3

0.01 $/Ton

0.05 $/Ton

0.2 $/Ton

1 $/Ton

5 $/Ton

25 $/Ton

125 $/Ton

Pumping Cost

$-

$2.00

$4.00

$6.00

$8.00

$10.00

$12.00

$14.00

$16.00

$18.00

$20.00

0 2 4 6 8 10 12 14 16 18 20

Loop Strength ppm

1.0 M

2.0 M

4.0 M

8.0 M

10.0 M

12.0 M

Season and Area LoadingSeason and Area Loading100 kg/Ha • Day100 kg/Ha • Day

Cost vs. days @ 10K$/ha

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0 100 200 300

Days per year

Series1

What can be profitable with What can be profitable with existing technology?existing technology?

Niche Markets ( > $10/kg)Niche Markets ( > $10/kg)– At a high enough price, all approaches workAt a high enough price, all approaches work

High Volume Markets -- low pricesHigh Volume Markets -- low prices– Pond culture systemsPond culture systems– Free water flow though system (agriculture Free water flow though system (agriculture

water or ocean net pens)water or ocean net pens)– PAS type systems using algae or marsh PAS type systems using algae or marsh

treatment systemstreatment systems

What can work in the Future?What can work in the Future?

Ecological control systemsEcological control systems

Feed Inputs

Sludge

Product Out

Economic ConclusionsEconomic Conclusions Recycle systems are expensiveRecycle systems are expensive

– Designs are based on Kg/day of feed inputDesigns are based on Kg/day of feed input– But minimal environmental impactBut minimal environmental impact

As an Extension AgentAs an Extension Agent– Recycle Aquaculture is high risk, capital intensive, Recycle Aquaculture is high risk, capital intensive,

knowledge intensive, hard work type of business. knowledge intensive, hard work type of business. Amateurs do not succeed. Amateurs do not succeed.

In the FutureIn the Future– Control over micro-biological ecology may decrease Control over micro-biological ecology may decrease

capital and operating cost.capital and operating cost.