An experimental plan has been developed to quantify the interactions of an integrated multitrophic aquaculture (IMTA) system with the surrounding environment. The small-scale IMTA system is designed for deployment in the coastal waters of New Hampshire, stocked with 2000 steelhead trout (Oncorhynchus mykiss). The fish are split within two containment bays of the floating structure made with high density polyethylene (HDPE) pipe, each with the dimensions of 6 m x 6 m x 3 m. The seafood system also includes 72 m of blue mussel (Mytilus edulis) droppers and 48 m of sugar kelp (Saccharina latissima) cultivation line that hang from the HDPE flotation pipe. The intent of the mussels and kelp as extractive species is to offset a portion of the dissolved and particulate nutrients from the fed steelhead trout.
To quantify the environmental interactions of the IMTA system with the surrounding environment, a comprehensive measurement plan was initiated utilizing both in-situ instrumentation and collection of discrete water and sediment samples. Two solar powered instrumentation packages have been designed to obtain temperature, salinity, dissolved oxygen, chlorophyl, pH, nitrate, fluorescent dissolved organic matter, and current velocities. One sensor suite will be deployed within the fish containment structure with the other at an external location approximately 100 m along the major axis of the M2 tidal ellipse characteristic of the site. With both flow and concentration values, mass flow rates, both in and out of the IMTA system, can be assessed. The instrumentation system is designed to transmit datasets to shore with cell phone communication. This will enable IMTA evaluation in real-time. Discrete water samples will also be collected to measure total ammonia nitrogen and nitrite, quantify plankton communities, and extract environmental DNA for metagenomic analysis. Sediment samples will be obtained to characterize potential benthic changes. The approach includes installation of a hydrophone mounted to the platform to evaluate changes in the soundscape and monitor presence of marine mammals. The presentation will include examples of preliminary datasets.