Assessing the potential for red seaweed Asparagopsis taxiformis aquaculture in Seychelles

Abstract

Asparagopsis taxiformis macroalgae can potentially reduce methane emissions when fed to ruminants, thus reducing the emission of greenhouse gasses into the atmosphere. Literature indicates water temperatures above 24 °C limit A. taxiformes growth rates during culture, however, it grows wild in Seychelles where water temperatures range from 25 to 31.5 °C. The feasibility of cultivating the local strain of A. taxiformis in Seychelles was investigated, focusing on growth rates at higher temperatures and bromoform content, the compound responsible for methane reduction. Two tetrasporophyte growth trials were conducted in photobioreactors at 24 °C, 26 °C, 29 °C and 32 °C. In the first trial, unacclimated specimens showed poor growth, with no significant differences between temperatures. In the second trial, daily growth rates of acclimated specimens were 3.98 % across all temperatures, including 32 °C, where temperature did not significantly affect growth. Bromoform concentrations were lower than expected, likely due to storage conditions prior to sample processing. The local strain of A. taxiformis in Seychelles may therefore be adapted to higher temperatures, with potential for aquaculture. Further research to optimize cultivation techniques and ensure adequate bromoform content is required.