Progress towards a land-based. aquaculture of the red seaweed, Palmaria palmata. David J. Garbary & Juan Manriquez-Hernandez. Dulse Nova Scotia Ltd.

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1 (St. Francis Xavier University Dalhousie University, Faculty of Agriculture) Progress towards a land-based aquaculture of the red seaweed, Palmaria palmata David J. Garbary & Juan Manriquez-Hernandez Dulse Nova Scotia Ltd.

2 DULSE NOVA SCOTIA LTD. Objectives: 1.To develop an economically viable, landbased aquaculture for the production of Dulse 2. To provide year-round production of Dulse to sell into local & world markets (match production of wild harvest in Nova Scotia) 3. To provide year-round employment in rural Nova Scotia

3 WHY AQUACULTURE? Market opportunities for Dulse are high Fundy Dulse (one of our partners) could market 5 times their current production -wild harvest is not sufficient Dulse in situ is highly dependent upon natural light, temperature and field conditions Crop failure in 2015 (50% reduction on Digby Neck) Storm damage from hurricane in Grand Manan (2013?) Much of current production is B-grade and not suitable for food market (particularly late in season)

4 Why Land-based? Complex life history... Need to grow plants vegetatively (stop growing when become reproductive and become tough) Year-round production becomes possible... -Avoid annual cycles of temperature and light -Wild harvest currently limited to wild harvest from (May) June-September during spring tides

5 History 1. Initial partnership between Dalhousie, Faculty of Agriculture, St. Francis Xavier & Scotian Halibut Ltd. (2008) Utilization of waste-water from halibut rearing facility to grow seaweed (multitrophic aquaculture) Initial research supported by NSERC Strategic Grant 2. Formation of Dulse Nova Scotia Ltd. (2014) Support from Nova Scotia Productivity and Innovation

6 IMPLICATIONS OF LAND-BASED AQUACULTURE Digby Neck Why? Human resources -expertise on Dulse locally available (i.e. Fundy Dulse Ltd.) Light less summer fog than Atlantic coast - close to southern limit of Nova Scotia (more natural light) Temperature -temperature more moderate ca C Water quality Dulse grows abundantly in these waters source of high quality natural strains

7 Constraints of land-based operation Temperature control requires energy (this is why Digby Neck) maintain at 10 C Less heating in winter 5 months Less cooling in summer 4-5 months Light control requires energy (Digby Neck has less fog less energy needed for power) Water circulation and pumping requires energy (requires low elevation site)

8 RESEARCH HISTORY Temperature (Corey et al. 2012, J. Appl. Phycol. 24:441) Dulse is a cold water species Grows better at 6 C than at 10 or 17 C Maximum growth 5.8% day -1 Nutrients (Corey et al. 2014, Algae 29:35-45; Corey et al. 2012, J. Appl. Phycol. 24: ; 25: ) Nitrogen source (ammonium and nitrate) up to 8.9% d -1 with high N (300 µmol N) 10:1 (N:P) Dulse density (Kim et al. 2013, Aquaculture 414: ) Stocking density (growth rate independent of stocking density between kg m -2 at 140 µmol photons m -2 sec -1 ) Light (Manriquez-Hernandez et al. 2015, Aquaculture International 24:39-55) Light is limiting max growth at 17.2 mol photons m -2 day -1 (full sunlight) Water circulation (Caines et al. 2014, J. Appl. Phycol. 26: ) Intermittent aeration (pump off at night during 16:8 (L:D) had no effect on growth)

9 RECENT RESEARCH (DULSE NOVA SCOTIA) 1. Preliminary business plan (P&I I) 2. Organic aquaculture (P&I - II) Why Organic? Premium product will receive premium prices? Use of certified organic nutrients -40 x cost of chemical additions (i.e., f/2 medium) Hydroponic plant growth not recognized as organic This is in review by Canadian standards organization CO 2 may be problem for certification

10 Parameters of experiment Experiment duration (January to March) -28 days for each of two experimental runs Media = 3 types: f/2 (control), 2 organic fertilizers 2 replicates of each condition, monitored weekly Tub volume = 16 L (28 L including header tank) Stocking density = 7 or 8 g L -1 in two experiments Irradiance = min of 300 µmol photons m -2 sec -1 (30 µmol natural light) ph control = 8.5 Nutrient control N= µmol P = µmol

11 EXPERIMENTS 1 & II Experiment I Commercial fertilization of f/2 medium and two commercial organic fertilizers Plants-based Fish based Experiment II Similar to Exp. I but supplemented with mineral supplement - organic trace elements(fe, Mg, Cu) Rubicon supplemented with micronutrients

12 Experimental details Experiment I monitored nutrients in the water to determine uptake Both experiments monitored plant composition and growth Growth determined on weekly basis using fresh mass Experiment II monitored bacterial growth associated with the plants

13 General results Certified organic media not significantly different from f/2 in terms of algal growth Fish-based fertilizer tanks developed yellow slimy coatings on tanks and tubing and could clog the tubing (ca. 5 mm diameter) more bacterial growth on plants Plant-based fertilizer more expensive than fish-based (40%)

14 COST FOR SEVEN DRY TONS DULSE f/2 medium - $15,000 Plant-based fertilizer- $650,000 Fish-based fertilizer- $500,000 -organic nutrients may be prohibitive as they will form too high a proportion of operating expenses -need to buy in bulk

15 GROWTH RATES PER DAY (%) (N = 4) Treatment Trial I Trial II (Originals) (plus minerals) f/ Plant-based Fish-based

16 Plant composition Composition of plants similar, regardless of medium No significant trends in composition of wild (i.e. starting plants) and after growth Carbon 31.7 to 35.2 % Nitrogen 3.7 to 4.9 % C/N ratio 7.7 to 10.1

17 Limitations of current experiments Nutrient loading Could be reduced by 50% (cost saving) Light regime not maximized (light too low - need 400 µmol photons m -2 sec -1 ) Tank size not maximized (more efficient tumbling) Higher stocking density not achieved (fall collection of starting material) Estimated growth rates with higher light 5-7 % day

18 Achieved and hypothetical growth rates and doubling times Achieved 3% per day Growth rate Doubling time 3% day days 5% day days 7% day days

19 GREENHOUSE AT 5% PER DAY - 15,000 kg y -1

20 Future Development 1. Another round of culturing to assess growth under pilot scale (ca. $100,000) for purchase or rental -large tank with optimized light, temperature, nutrients, aeration, stocking density... OR 2. Move directly to greenhouse facility for commercial growth. ($2.4 million) Both require significant financing for infrastructure. 15,000 kg of premium Dulse used for flakes $600,000 revenue at base price (after production cost)

21 ACKNOWLEDGEMENTS NSERC Strategic Grant NS Productivity and Innovation I & II Dr. Jim Duston Fundy Dulse Ltd. (Wanda & Calvin Van Tassel) Meinhard Pfanner Dalhousie Aquaculture Centre

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