In the scope of integrated marine aquaculture the polychaete (bristle worm) Nereis diversicolor has been used to recycle fish feces and bacterial biomass.
Within the project a bioreactor design for the cultivation of polychaetes has been developed and optimized.
The worm production in the bioreactors represents a source of valuable raw material. It can be used directly as feed supplement in aquaculture. On the other side, the worm can be sold, for instance as live bait for sport fishing.
The project proved successfully the principle design of the bioreactor, functioning as a habitat for polychaetes while at the same time representing a component of water treatment in a recirculating aquaculture system. The polychaetes showed positive growth in all samples independent of substrate or waste type.
The analysis of amino acids showed that Nereis diversicolor has an excellent nutritional value to use it as a protein source in aquaculture. In addition, the composition of amino acids of worms fed by waste from aquaculture production has improved compared to natural conditions. This indicates, that fish feces can be used reclusively as food for polychaetes. Furthermore, the analysis account for eight essential amino acids, which can be also applied for human feeding.
The project was supported by the Bremerhavener Gesellschaft für Investitionsförderung und Stadtentwicklung mbH (BIS).