Nutrient recycling

Artificial wetland with Halophytes
Artificial wetland with Halophytes
Separated fish waste
Separated fish waste

Results from various aquaculture systems show, that a huge part of nutrients in fish diets is excreted in dissolved and particulate form. The physiological limits to optimize the nutrition of fish diets, in order to improve the feed conversion, seem to have been reached for many fish species. The technology of the oceanloop enables the recycling of these nutrients, as they can be reused by so-called secondary organisms, which are produced in addition to the actual target species (primary organism).

 

The integration of fish production with secondary organism provides serveral opportunities. The dissolved nutrients, such as primarily nitrogen and phosphorus compounds, can be used by algae or aquaponics . The particulate nutrients, such as fecal matter and food remains are used by invertebrates, which filter them (e.g. mussels) or feed them from the ground (e.g. polychaetes or sea cucumbers). Artificial wetlands represent a mixed form, in which the biology is left to itself and develops its own, complex food webs. 

 

The additionally gained biomass can be used either directly (food additives, larvae rearing and fry production) or indirectly (energy gain through fermentation).

 

In the future integrated aquaculture systems will define the state of the art, as they ensure an extensive recycling of nutrients and energy. These systems reduce the environmental impact and improve the profitability of aquaculture.