Seaweed mariculture is a quickly growing sector of the aquaculture industry, especially in the United States. Macroalgae are being cultivated as food products, feedstocks, and sources of nutraceuticals, biopolymer compounds, and water quality bioremediation. While most growth in the North American seaweed sector has taken place in colder climates (Maine/Alaska/Pacific Northwest), warm water macroalgal culture has lagged behind. Coastal Alabama may provide an ideal location for piloting some of the first commercial warm water macroalgal farms in the northern Gulf of Mexico.
Potential locations within Alabama state waters were screened for environmental suitability factors (salinity, turbidity, depth, benthic substrate, critical habitat), maritime usages (shipping, military, existing aquaculture), and infrastructure considerations (proximity to ports). Nearshore farms offer benefits of lower operational costs due to simplified regulatory requirements, proximity to processors, and less costly gear arrays. Additionally, nearshore macroalgal culture can provide nutrient remediation of coastal river plumes and enhance availability of complex 3-dimensional habitat for fish and invertebrates. Past studies conducted by the Auburn University Shellfish Lab have shown that macroalgal culture is not optimal in tandem with oyster aquaculture, as these areas are shallow with high turbidity, temperatures, and salinity flux. However, sites south of the coastal barrier island complex may yield more ideal growing conditions.
Based on the physical environmental regimes and the native algal species assemblages in the northern Gulf of Mexico, target genera for cultivation include: rhodophytes such as Gracilaria and Eucheuma, chlorophytes such as Caulerpa and Ulva; and phaeophytes like Sargassum. Some of these genera are clonal, and can be cultivated via fragmentation, whereas others need to be raised in a land-based nursery to seed ropes for grow-out.
Few of the proposed algal species are ideal for human consumption, so this region would primarily serve agriculture (both fertilizer and livestock feed), biopolymer, bioplastic, and biofuel markets. Approaching algal mariculture as industrial scale commodity production - as opposed to boutique and artisanal food production- presents unique challenges, namely in scale, labor, regulation, and environmental impact. If this project is carried out responsibly and thoughtfully, these same challenges become opportunities - not just for economic impact, but for large-scale environmental benefit in the excess-nutrient encumbered Gulf of Mexico.