Aquaculture Program

Effluent Management

Effluent Management includes the integration of intensive marine finfish culture with the nursery culture of marine bivalve mollusks to reduce the nutrient composition of RAS effluent and to develop efficient techniques for producing bivalves for stock enhancement and habitat restoration projects. Converting expensive nitrogen and solid waste into a valuable product will increase overall profit for the farmer, while reducing environmental pollution. Research focuses on RAS effluent-based culture of Isochrysis galbana and Tetraselmis suecica and wild phytoplankton in polyculture with the eastern oyster Crassostrea virginica and the hard clam Mercenaria mercenaria.  Geotextile fabric tube (Geotube) technology is being evaluated to remove solid wastes from marine finfish RAS effluent, while salt-tolerant marsh plant such as Salicornia virginica are used to biomitigate dissolved nutrients from the Geotube filtrate before release to the environment or reuse in the RAS.  Integrated multi-trophic aquaculture (IMTA) where wastes from fish are used as fertilizer for other valuable crops can reduce economic losses due to underutilization of feed and increase profitability of RAS mariculture for the farmer.

Juvenile oysters are used to filter effluent-grown microalgae.
Juvenile oysters (Crassostrea virginica) are used to filter effluent-grown microalgae.

Biofilter culture of effluent-grown Chaetoceros sp.
Biofilter culture of diatom sp. Chaetoceros grown from black sea bass effluent.

Salicornia sp. sample from effluent mitigation trial.
Salicornia sp. sample from effluent mitigation trial.

Experimental set-up for Salicornia effluent mitigation trial.
Salicornia sp. experimental set-up for black sea bass effluent mitigation trial.

Effluent-grown microalgae in culture cylinders.
Effluent-grown microalgae in culture cylinders.

Oyster filtration of effluent-grown microalgae trial.
Oyster filtration of effluent-grown microalgae trial.

Oyster filtration between two treatments.
Oyster filtration between two treatments.

Collaborator Sturgeon City's future site for Ruppia sp. mitigation.
Collaborator Sturgeon City's future site for Ruppia sp. mitigation.