Utilizing Recirculating Aquaculture Systems to Evaluate the Impact of Oil Toxicity on Marine Fishes: Design and Operation of a Large-Scale Experimental System

Abstract

AbstractThe long-term damage of oil spills and recovery efforts on wild fishery populations are not well understood. In order to assess potential biological effects of dispersed oil exposure on Gulf of Mexico fishery populations, C-IMAGE (Center for Integrating Modeling and Analysis of the Gulf Ecosystem) scientists examined the sublethal impacts resulting from the 2010 Deepwater Horizon oil spill through a combination of field collections and controlled laboratory exposure experiments. Mote Marine Laboratory scientists and Complete Water Services, LLC (Marietta, GA), engineers partnered to design, develop, and operate a large-scale, zero-discharge, experimental oil contaminant exposure system at Mote Aquaculture Research Park in Sarasota, Florida. This exposure system is linked to a recirculating aquaculture system (RAS) designed to maintain water quality and water chemistry within acceptable parameters and to remove oil and dispersant from system water during the filtration process. Equipment was sourced to ensure that potential oil co-contaminants were not retained within the system. Water quality (oxygen, pH, salinity, temperature) and chemistry (ammonia, nitrite, nitrate, and alkalinity) parameters were monitored and controlled to maintain appropriate environmental conditions for marine fish during experimental trials. The concentrations of petroleum components throughout the system during exposure trials were monitored to ensure that the system was meeting the design parameters. Experimental trials were conducted using the exposure system with three important Gulf of Mexico marine fishes, Florida pompano (Trachinotus carolinus), red drum (Sciaenops ocellatus), and Southern flounder (Paralichthys lethostigma). These trials examined the impacts of dispersed oil exposure on facets of fish health including gene expression, transcriptome, immune function, DNA damage, shifts in the microbiome, reproductive potential and success, and the F1 generation from exposed parents. The system was operated successfully through the trials and allowed us to maintain consistent and appropriate water quality conditions in the experimental tanks. The recirculating filtration system successfully maintained water chemistry and removed oil contaminants during the fish exposure trials. The application of the system technology applied in this study has broader applications than the study of hydrocarbon impacts and opens the door for investigation of a wide range of different contaminants.