Experimental cultivation of seaweed on the coast of Cox’s Bazar, Bangladesh: identifying the effects of environmental parameters on seaweed growth

Abstract

The current study was carried out at Rezu Khal to determine the ideal area for seaweed farming. Additionally, this investigation uncovered species of commercially productive and lucrative seaweed. Temperature, salinity, pH, dissolved oxygen (DO), conductivity, and Formazin Nephelometric Units (FNU) of surface water ranged from 20.9 to 26.2°C, 24 to 26.2‰, 6.45 to 8.5, 92 to 105%, 33,256 to 64,267 μS/cm, and 11.1 to 42.8, respectively. Phosphate-phosphorus concentrations in surface water were 2.6–7.6 mg/L, 0.04–0.12 mg/L for nitrate-nitrogen, 0.002–0.04 mg/L for nitrite-nitrogen, 0.15–0.83 mg/L for silica, and 0.13–0.28 mg/L for ammonia. Three seaweed species (Gracilaria lemaneiformis, Hypnea musciformes, and Sargassum oligocystum) were cultivated in the selected areas. Two methods (net and long-line) were used for the culture. In this study, 15–20 kg of G. lemaneiformis were harvested every 15 days using the net method. H. musciformes gained 4 to 12 kg every 15 days. Although S. oligocystum thrived nicely, it was challenging to maintain its viability. The findings of this study indicate that seaweed farming is feasible and coastal residents may participate in seasonal income-generating endeavours in coastal waters.