Macroalgae Aquaculture in Southwestern Florida as a Potential Tool for Nutrient Sequestration

Abstract

Excess nutrients from terrestrial sources have led to rapid growth of invasive, and often opportunistic, algal species, creating dead zones and causing degradation of the coastal ecosystem. Low levels of oxygen within these areas, an ultimate consequence of excess nutrient flux, contribute to harmful and deadly environments for marine life. Most macroalgae, however, are not harmful and are well known for the ecosystem services they provide, perhaps the most important of which is nutrient sequestration. The ability of macroalgae to sequester nutrients as part of their normal life cycle, combined with their potential market demand, illustrate that macroalgae can be used to restore eutrophic waterways while simultaneously creating economic opportunities through the practice of aquaculture. To determine the viability of macroalgae aquaculture in Tarpon Bay, located in Sanibel, Florida, three testing sites along with two different treatment methods (enclosed vs. exposed) were established. All testing sites were equipped with two aquaculture lines with clusters of macroalgae attached by fishing line, as well as macroalgae samples enclosed in mesh bags. The goal of this project was to see which of three species of macroalgae would grow best, which treatment method was best for aquaculture success, which locality within Tarpon Bay would lead to the greatest amount of algal growth, and which environmental parameters were most important for overall growth of each species.