Alternative feeding recources

The pressure on the global fish stocks is increasing through the steady growth of the human population and its demand for high quality fish products. The fact that a further enhancement of fish stocks is no longer possible and an increasing demand toward fish exists, shows that the natural fish production (through reproduction) has reached its limits. In summary world fishery cannot supply the growing demand of humans with sufficient fish products because large parts of the natural reserves are already destroyed by overfishing. With the help of aquaculture, the breeding of aquatic organisms, natural resources can be conserved and simultaneous the future supply of fish could be saved.

But also here one needs to keep relying on the fishery sector in the traditional sense, because aquaculture is also dependent on fishery products as food source for cultured organisms. Trout, sea bass and other carnivorous fish species feed on fish meal, a resource which will always have a high demand and subsequently be expensive. So it is important for the development of aquaculture to develop an alternative feed to assure the future supply of humans with fish and to give the natural population the chance to recover once again.

At first a proper organism would need to be found which equates the classic feed in their substances of content to develop a new one out of this model. The tested species are organism, which are native to the North Sea, are abundant and basically live in the ecosystem Wadden Sea. The test species would be analysed to find its substances of content and its chemical composition with a fatty acid analysis, C/N analysis and a calorimeter analysis. These results will be compared to a reference specimen of traditional feed. Also the economic and the biological aspects will be compared among each other (like reproduction of the organism or the husbandry and conversion of feed) to assign the organism which is qualified as the best for the further processing to an alternative feed. Following organisms were analysed for this project: Mytilus edulis (blue mussel), Caprella mutica (ghost crab),  Littorina littorea (common periwinkle), Nereis diversicolor (estuary ragworm), Carcinus maenas (common shore crab), Corophium volutator (sandhopper),  Crassostrea gigas (pazific oyster), Arenicola marina (blow lug).