Comparative Evaluation of Eucheuma denticulatum Productivity in Floating Raft Systems: Integrated versus Monoculture Systems in Kwale County, Kenya

Abstract The research study aimed to compare biomass productivity between these systems using polynomial regression to model seaweed growth. Seaweed was cultivated over 49 days using floating rafts, with twelve seeded ropes per raft and one unseeded control line. In the IMTA setup, rafts were placed approximately 30 meters from the fish cages stocked with Siganus sutor. Environmental parameters, including temperature, pH, salinity, dissolved oxygen, and total dissolved solids, were measured and found to be within acceptable ranges for seaweed farming. At Kijiweni, dissolved oxygen and salinity levels were lower than at Kibuyuni. Growth data fitted well with polynomial models (R² ≈ 0.99), allowing estimation of intermediate biomass trends. Overall, the monoculture system outperformed the IMTA system, with substantially higher growth rates and yields, while IMTA results remained within biologically plausible ranges reported in prior studies. The findings suggest monoculture systems offer higher short-term yields while IMTA systems may provide long-term ecological benefits. The study highlights the importance of environmental conditions and system configuration in seaweed farming. It indicates the need for longer-term studies to fully assess IMTA's potential for supporting coastal livelihoods.