In 2020, the Gulf States Marine Fisheries Commission (GSMFC) funded “From Guts to Glory” (GTG) within the College of the Florida Keys Southernmost Marine Aquaculture and Research Training (SMART) Center. Introducing black grouper (Mycteroperca bonaci) aquaculture, our project goals are to house female broodstock (RAS), simulate natural spawning stimuli for brood (temperature regulation, photoperiod control, and audio stimulation with male courtship calls), and for the first time with this species, perform invitro fertilization with female eggs and sourced male gametes. As a revolutionary stock enhancement plan for the Florida Keys National Marine Sanctuary, the CFK (College of the Florida Keys) SMART Center looks for better strategies to improve our RAS and increase technician efficiency. After three years of study, the GSMFC grant expanded into integrated multi-tropic aquaculture, highlighting the Eastern Oyster (Crassostrea virginica) and the Florida Keys local species of red macro-algae, Asparogopsis taxiformis.
Having upgraded the system to incorporate IMTA benefits 1) the outstanding water quality issues with low pH and excess nitrates and 2) reducing the number of gallons necessary to complete daily water changes. A. taxiformis has been chosen as the system macroalgae species as the absorbed nitrates and excess nutrients increase our supply, we would sell the supply to local Southern Florida cattle farmers as livestock feed to reduce methane production. However, as there are two lifestyle phases for this species: 1) Falkenbergia (found in warmer seasons) and 2) Asparogopsis taxiformis (found in cooler seasons), the timing of algae collection must be coordinated with the second life stage cycle of the species for our purposes. No confirmed collection of the species has been gathered. As a placeholder in the system until positive identification of A. taxiformis, green macroalgae Ulva lactuca and Chaetomorpha spiralis have been used to monitor water quality in the GTG system.
Our first attempt with 500 spat of the species, C. virginica, remains in a trial phase until water quality concerns have been remediated. C. virginica has not been placed into the main GTG system as maintaining system pH is a challenge. Technicians work with the species in trial conditions to stabilize their ambient pH and increase growth rates through feed studies with 1) Nannochloropsis oculata & Isochrysis galbana 2) concentrated algal paste (Rotigrow plus) and 3) Shellfish Diet 1800.
In conclusion, further study with C. virginica will be continued at the College of the Florida Keys Southernmost Aquaculture and Research Training Center. Collection methods for A. taxiformis will be further explored during the winter season.