Growing shrimp with extractive species is gaining momentum as an effort to reduce effluent waste in shrimp aquaculture. At University of New Hampshire’s Coastal Marine Laboratory, oysters and red algae were incorporated into a shrimp recirculating aquaculture system to determine their effectiveness in reducing ammonia waste. This is a critical step in reducing negative impacts to ecosystems surrounding shrimp aquaculture operations, while producing valuable biproducts .
An aquatic habitat system (AHAB) was used, which consisted of 36 individual 9L tanks vertically stacked into 9 columns and 4 rows, each column making up an isolated system. A 4-week trial was conducted comparing three treatment types: 1) shrimp grown with oysters and red algae, 2) shrimp grown with only red algae , and 3) shrimp grown with red algae as well as aeration to re-suspend waste particles. No additional biofilters or mechanical filters were used.
A second one-week trial was conducted to compare shrimp grown with different ratios of shrimp to seaweed biomass. Shrimp were grown with the same ratio as the first trial , a shrimp: seaweed ratio of 1:2, as well as an increased ratio of 1:4 and 1:6. Water samples for both trials were collected once a day before feeding, and once a week before feeding and at regular intervals up to five hours after feeding. Biomass data was also collected once a week throughout the experiment. Results for both trials were analyzed by measuring ammonia concentrations in water samples and will be shared.