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Shellfish hatchery/nursery/grow-out
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Acronym |
SHANGO |
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Start & end date |
May 2006 - July 2008 |
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Funding & funded by |
Innovation in Aquaculture Funding Scheme (Ministry of Agriculture, Nature & Food Quality) and the Zeeland Provincial Authorities. |
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Objectives |
- To develop, scale up and test a prototype for a shellfish hatchery/nursery/grow-out system in the Netherlands (on the basis of existing techniques).
- To draw up a Business Plan for professional hatcheries/nurseries (with sufficient capacity for part of the annual demand for shellfish broodstock).
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Summary |
The project is primarily aimed at mussels and developing and testing a prototype hatchery/nursery and grow-out system. A business plan will contain a detailed report of:
- the technical design and layout
- technical, economic feasibility
- the working method, laid down in protocols
An important link in the controlled chain is the survival and development of the mussel broodstock after the phase of the nursery on the bottom. The sooner the brood can leave the nursery, the less manpower, feed, energy and water they will need during the nursery phase. Attention will be focused on factors that will enhance survival rates on the bottom.
The project aims to produce at least 500 million mussel broodstock per year, which is viable on the culture plots. In terms of the grow-out, the aim is to increase the yield by a minimum of a factor of two. |
| Results |
The project focuses on further development of the techniques needed to scale up to a level that will provide sufficient capacity for part of the annual demand for shellfish broodstock. The results of the project will show how feasible this is.
Nurture, conditioning and selection of parent animals
Up until now, the best broodstock has been used, selected on the basis of hatching and survival rates of the larvae. The broodstocks come from Ireland and Shetland. Mature broodstock can be kept at low temperatures in early spring and allowed to spawn until the autumn. Various tests have been carried out whereby the temperature was gradually raised and large amounts of feed administered. Fat mussels can be prepared for spawning within 3 weeks. The effects of a constant high or low temperature are currently being tested, as are the effects of various algae diets and food supplements.
Developing and scaling up a cost-effective system for breeding algae
Roem van Yerseke’s existing batch cultures have been scaled up to 100 litres and CO2 has been added. This is effective for both the diatoms and the flagellates. The 100-litre batch cultures are currently transformed into continuous cultures. IMARES is testing Wageningen University´s flat plate reactor for the species relevant to the shellfish hatchery: Isochrysis galbana, Pavlova lutheri, Chaetoceros calcitrans, and Chaetoceros gracilis. Skeletonema and Chaetoceros were bred in basins with groundwater. The results varied according to the quality of the water. The quality tended to fluctuate; the iron levels were sometimes a problem. In good-quality water, a concentration of 1 million cells per ml could be achieved in 5 days. Alongside this, algan bloom was produced in basins by enriching the water with nutrients from filtered seawater. The dominant species were Dunaliela and Phaedactylum.
Photo 1: Flat plate reactor and basins with algae
 Developing and scaling up hatchery and nursery systems
Six food supplements were tested. One of the supplements tested produced greater settlement success. A spat diet on the basis of food supplements is available for the market.
Various types of algae were tested. The results indicated that a higher growth rate was achieved with Chaetoceros calcitrans than with Chaetoceros gracilis. The difference in growth rates was still evident in the nursery phase. Growth and survival rates of the larvae differ according to the origins of the broodstock. Larvae from Grevelingen broodstock grow faster and have a higher rate of survival than larvae from the Oosterschelde. Larvae cultivation was scaled up by using flow-through tanks in which high densities of the larvae could be kept. Various substrata were also tested. The conclusion was that many substrata are suitable for keeping larvae. The most important factor, however, is which substrata are suitable for growing-out the broods.
Photo 2: Broods in the Roem van Yerseke hatchery
Improving the survival rate of the seed in open water
Nets with broodstock were put out in hanging cultures. The broods grew well. The survival rate of hatchery broodstock was also tested by sowing it onto a bottom plot of Prins & Dingemanse in the Waddenzee at the same time as MZI seed and bottom seed. The hatchery seed had a lower rate of survival than the MZI and bottom seed. |
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Staff involved |
Pauline Kamermans, Ainhoa Blanco, Emiel Brummelhuis, Johan Jol, Marnix Poelman, Jeanet Allewijn, Frans Veenstra |
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Position |
Scientific support, coordination and management |
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Cooperation Partners |
PO Mosselcultuur
Roem van Yerseke (hatchery/nursery)
Prins & Dingemanse (grow-out) | |