New Emerging Trends in RAS

Steven Summerfelt

3rd RAS Conference Sunndalsora, Norway

OUTLINE

• Trends – Biosecurity – Increased production scale – Water Quality Limits – Increased oxygenation and CO2 removal – Land-based salmon growout – Capture, dewater, & dry biosolids – Conclusions

Cultured Fish, Eggs

Water Supply

Equipment

Personnel

Feed

Aerosol

Birds

Mink, otter

Fish

Aerosol

Trend: Biosecurity Focus in RAS

• Exclude obligate pathogens – healthier fish ̶ Reduce mortality & improve health and performance ̶ Reduce or eliminate vaccine, antibiotic, & pesticide use ̶ Avoid losses and costs of mitigating:

• sea lice, viruses (ISA, PD), amoeba, obligate bacteria, toxic algae • storms, marine mammals, • super chill

Wild fish & foods

Parasites

Biosecurity Focus in RAS

ü Implementation: o Farms are shifting away from surface water sources

• RAS are used to minimize water flushing • sophisticated filtration & UV irradiation to disinfect

makeup water o Farms introduce only pathogen-free eggs (when possible)

• avoid introducing fish carrying disease

Trend: Increasing Production Scale

• Scale of land-based projects is increasing –1,000 to 6,000 ton/yr under one roof – smolt/post-smolt – food-size fish

Increasing Production Scale

• Example: 1,000 MT/yr of salmonid production – 11,000 to 16,000 m3/hr RAS flow for water quality

• < 80 m3/hr of makeup water (about 99.5% flow reuse)

– 4-5 MT/day feeding – 6,000-10,000 m3 growout volume

• approximation with many variables

Photo credit: Bell Aquaculture

Increasing Production Scale

• Capital cost for 1000 MT/yr farm ranges from about $10 to $17 million – Potential to reduce capital costs

Trend: Economies of Scale

• Economies of scale – Reduce fixed-capital costs and operating costs – Savings in capital per ton production

• Smaller building footprint • Fewer culture tanks, pumps, filters, biofilters, gas balancing units • Fewer water quality monitoring points, SCADA, feeders, pipe runs, etc. • Centralized grading & vaccination

– Cheaper to build one giant RAS than multiple small RAS • Compromises & tradeoffs

Trend: Water Quality Limits

• Regulations & performance criteria govern water quality limits for healthy fish culture

Dissolved O2 100% sat.

Total Gas Pr. ≤ 100% sat.

CO2 < 15-25 mg/L

NH3 < 0.01-0.02 mg/L

NO2-N < 0.2 mg/L

NO3-N < 80 mg/L Example of guidelines used at Freshwater Institute for trout & salmon

Trend: Increase Available Oxygen

• Increasing available O2 without creating total gas super-saturation = increased production – Be careful of high-pressure side-stream units – Be careful of aerating deeper than 1-2m (MBBR)

– Treat full-flow at low pressures using vented oxygen transfer technology • create O2 super-saturation while venting N2 off-gas

to the atmosphere • reduces the opportunity for total gas pressure

super-saturation.

Increase Available Oxygen

• Low Head Oxygenation (LHO) Units – Treat entire RAS flow – Low head/energy (0.5-1 m total dynamic head) – Efficiently produces 150-200% O2 saturation – Near 100% O3 transfer – Vents N2 & avoids TGP – Scales to high flows

PRAqua

(REDUCE ENERGY USED IN

OXYGENATION)

Aerator Pump

Trend: Increase CO2 Removal

• Locate adjacent to the culture tank – improve energy efficiency & reduce fixed costs of CO2 stripping

Airlift Pump Cascade Column and

Axial Flow Pump

(BE SMART, BUT EXECT TO USE ENERGY TO REMOVE CO2)

Airlift Pumps & Cascades Aeration Outside Large Circular Culture Tanks

Airlift Pumps INSIDE TANKS

Airlift Pumps OUTSIDE

TANKS

Air Lift Pumps INSIDE SQUARE TANKS

Cascade Exiting Tank Side-Drain

Culture Tank CO2 Depends on Daily Feed Load and Fan Speed

0 5

10 15 20 25 30 35 40 45

0,0 100,0 200,0 300,0 400,0

Dis

solv

ed C

O2,

mg/

L

Daily Feed Rate in a Culture Tank, kg/d

50 hz 30 hz 20 hz

Forced ventilation Cascade Column

Trend: Land-Based Salmon Growout

• Producing salmon in RAS is biologically and technically viable

• Industry is testing whether producing salmon in RAS is economically viable

• Location, location, location • Permits can be obtained • No site-license system to

stop the farm

Trend: Land-Based Salmon Growout

1. KUTERRA (Canada)

2. Golden Eagle Aqua (Canada)

3. Spring Salmon (USA)

4. Bell Aqua (USA)

5. Freshwater Institute (USA)

6. Sustainable Blue (Canada)

7. BDV (France) 8. Langsand Laks (Denmark)

9. Danish Salmon (Denmark)

10. Jurrasic Salmon (Poland)

11. Xinjiang Ehe (China)

12. Shandong Oriental OT(China)

1,2

4 6 8,9

10 3 5 7 11

12

(Facilities harvesting fish or at least with eggs stocked)

Land-Based Salmon Growout

• One of ten Norwegian “Dark-green licenses” – Senja Akvakultursenter AS – To produce harvest size salmon, on-land

• Norwegian government to decide if land-based farms should be connected to the sea license-system and pay license fee

• Large land-based farms in planning stage: – Norway, Sweden, France, Scotland, USA, Canada, China – No requirement to pay sea license fee outside Norway

Land-Based Salmon Growout

Male Harvests

Premium Harvests

0

1000

2000

3000

4000

5000

6000

0 200 400 600 800 1000 1200

Mea

n Si

ze (g

)

Age (Days)

1208 Gaspe Bay

111 Cascades

109 St. John River

110 St. John River

1208 Gaspe Bay-109 St. John River Mixed Cohort Net Pen STJR

212AS Cascades

1212AS SB

Average Harvest Weight

23-25 months post hatch to 4.5 kg

(16-18 months post-smolt)

Data from Atlantic Salmon growout trials at Freshwater Institute

Land-Based Salmon Growout

Trial #2 Trial #3 Trial #4 Trial #5 Strain St John River Cascade Cascade SalmoBreed

Density 36 kg/m3 100 kg/m3 118 kg/m3 tbd

• Maximum Growout Density in freshwater

(Mean CO2 = 14 mg/L; Max CO2 < 20 mg/L at highest density)

Atlantic Salmon Growout Trials

• Early Maturing Males Trial #2 Trial #3 Trial #4 Trial #5

St John River Cascade Cascade SalmoBreed Grilse harvest size, kg

2.7 & 3.7 2.6 2.1 2.2

Prevalence, % 36.6 38.5 17.1 18.0 Post-harvest use

Hot smoked Cold smoked

Fresh fillets & smoked

Fresh fillets

High maturation: Post-smolt initially comingled with previous cohort that

were maturing

Land-Based Salmon Growout

• Trial #1: – All females Gaspe strain, – 1 to 2% sexually mature

0

400

800

1200

1600

2000

2400

2800

3200

3600

4000

4400

247 277 308 338 369 400 428 459 489 520 550 581 612 642 673 703 734 765 793

Wei

ght (

g)

Days Post-hatch

Gaspe (Continuous Light + S0 Winter)

Gaspe (Continous Light)

St. John's (Continuous Light + S0 Winter)

St. John's (Continuous Light)

24 months

post-hatch

Land-Based Salmon Growout

• No major fish health events were noted – A little fungus, mostly during incubation & fry culture

• Tested sixty fish from each cohort – No sea lice or kudoa – No ISAV, IPNV, VHSV, OMV, SVCV, A. salmonicida,

R. salmoninarum, Y. ruckeri, M. cerebralis, C. Shasta, or K. thyrsites

• No vaccination, antibiotics, formalin, or pesticides used at any time in over a decade

• No escapees

Data from Atlantic Salmon growout trials at Freshwater Institute

Trend: Capture & Dewater Biosolids

• Gravity thickening settling units – Lower fixed & variable costs – No coagulant / flocculants required to 5-10% solids

– Low maintenance – Farmer friendly

Trend: Dewater & Dry Biosolids

• Dry biosolids to avoid storage lagoons (odor), reduce transport volume, & prepare for composting

30-40% CAKE

ROLLERPRESS

35% dry weight

Trend: Reclaim Nutrients

• Nutrients in biosolids & effluent can be reclaimed – Agronomic application of

biosolids to crops – Compost – Aquaponics

Trend: Remove Nitrogen

Woodchip Bioreactor Membrane Biological

Reactor

Conclusions

• Seafood production must increase • Closed-containment systems can increase seafood

production in the face of: – water resource limitations, – pollution restrictions, – siting restrictions, and – mounting disease challenges

• MORE RESEARCH

Acknowledgements

ØResearch support

Use native, freshwater snails to clean RAS surfaces and mitigate off-flavor in RAS

Bioremediation

Ø Total solids (biofilm) per area

• Snails - 0.03 ø 0.02 mg/cm2 • No Snails – 1.16 ø 0.16 mg/cm2

Ø Off flavor results still pending

Ø 100 snails, Physa gyrina, completely grazed the submerged surfaces of 50 gallon tanks within replicated reuse systems (left)

Ø Systems without snails had substantial

biofilm accumulation (below)

Snail Treated RAS

No Snail Control RAS

Bioremediation

ØSnails control biofilm accumulation on surfaces ØRapid snail reproduction & distribution ØWaiting for data on geosmin & MIB accumulation ØMore research necessary

Bioremediation

Ø Disinfect between cohorts Ø Use no water aeration media in

depuration systems because it provides surface area for biofilm attachment and is difficult to clean and disinfect

Ø Use simple partial-reuse or flow-through

systems and avoid treatment processes with difficult to clean areas

SOP’s for Depurating Salmon