Effects of Elevated CO₂ Concentrations on Proximate Composition and Bromoform Content in the Alga Asparagopsis taxiformis

Abstract

Global warming has affected marine ecosystems including seaweeds that play an important role in biodiversity and climate change mitigation. This study aimed to evaluate the impact of carbon capture treatment on growth, bromoform content, and proximate composition in Asparagopsis taxiformis, which is known to reduce methane emissions in the livestock sector. The study was conducted on a laboratory scale with CO₂ injection treatment at concentrations of 700 ppm (PA), 1000 ppm (PB), and 1300 ppm (PC), as well as a control without carbon injection (PK). Parameters observed included absolute growth, water quality, proximate composition, and bromoform content. Data were analyzed using analysis of variance (ANOVA) at the 0.05 significance level, with Tukey's post hoc test to compare differences between treatments. The results showed that all treatments experienced negative growth, with PC showing the slowest negative growth and having the highest crude fiber content (0.795%). Bromoform concentration in carbon-induced Asparagopsis taxiformis was higher (24.024 ppm) than that without carbon injection treatment. Although carbon capture treatment increased the bromoform content, it had a negative impact on growth due to a decrease in acidic water pH. These findings indicate the potential of Asparagopsis taxiformis as an environmentally friendly feed, but require optimization to support better growth.