From Sea to Land back to Sea?

Dr. Ronald de Vos, aquaculture expert

Ronald de Vos

• PhD in Marine Biology (Univ. British Columbia, Vancouver)• Remote Setting of Oyster Larvae

• Researcher TNO• Shellfish development of aquaculture techniques• Oil spill recovery (ITOPF-Londen: aquaculture expert)

• Director Aquaculture Royal Prins & Dingemanse• Innovation of shellfish culture, shellfish fisheries (oysters/mussels/cockles)

• Independent consultant for aquaculture: DeVoCo

• Co-fouder of: Renart Boulon: Oysters with taste

• Co-owner of: Algae Holland: algae trading

• Co-owner of Aquamarine: algae culturing

DeVoCoR&D - Management - Consultancy

Perspective on shellfish culture:from Sea to Land back to Sea?• Gathering of shellfish

• Fishing on banks and flats, no culturing just harvesting from nature

• Hardly any restrictions (period of year)

• Can you make a living?

• No quality standards

• “Food of the poor”

• Culturing and Processing of shellfish• Culture plots, seeding – re-laying – harvesting (from nature)

• Depending on availability of seed

• Environmental restrictions

• High quality (control)

• Shellfish is trendy

• Development of techniques, it’s farming and fishing: aquaculture• Off-bottom / rope-culture / vessels / processing

MSCI – MZI (malzwin)

• Land-based shellfish (intensive controlled culturing)

• Hatcheries• Broodstock from nature or selection (breeding: genetic-phenotypic)

• Finishing• Claires – feeding

• Complete culturing• Abalone

• Oysters – Clams – Mussels first experiments in Yerseke• Culturing of feed = micro algae

Zeeland Aquaculture: our experience

• Culture of Mussels – Oysters – Clams• Separate and in poly-culture: rope – basket/trays – in-bottom

• 5x ponds (100m2) – 8x long ponds (100m2)

• 250m3 raceway-recirculation with seaweed: 90-95% re-use water

• Pump seawater, water filtering: 250-50-5micron, salt well water

• Culturing feed• Tested 55 species of algae: growth-quality-taste

• Selected 3 species: mono-culture mixing in cocktail (diatom-flagellate-green)

• 5x Raceways – 10x ponds (100m3)

• Cont. Block harvesting, prod.time per pond 21-30days, down time: 30days/year

Groeicurve algencultuur

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• Feed production: 100-150ton dw algae / ha / year

• Growth rate: from seed to (small) consumption in 16-20months

• FCR: 0.6 – 0.9 dw algae : ww shellfish

• Mortality: 2-4% (20% incidents)

• Production: Cost:• Clams: 10-15kg/m2 7-10euro/kg

• Oysters: 10-20kg/m2 5-10euro/kg

• Oysters fattening 3-5euro/kg

• Mussels: 40kg/m3 >15euro/kg

Discussion

• Land based shellfish is too expensive

• Use of closed circuit water / re-use process water

• Culturing of feed (algae) separate from shellfish culture