Mariculture Potential of Seaweeds: With Special Focus on Gracilaria Cultivation

Gracilaria verrucosa (Hudson) Papenfuss has been extensively exploited from natural stocks as a source of agar and the eco-materials in the Indian water. This has resulted a rapid depletion in its natural biomass. To overcome this problem, mariculture practices are essential to be adopted. The development of easy and fast-growing methods of seaweed cultivation is therefore of high importance. Hence, production and performance of suspended Gracilaria cultivation methods using spore-inoculated ropes and vegetative fragments in raft technique were studied in the waters of Gulf of Mannar. The DGR (daily growth rate) of 11.9 % d−1 and 4.69 % d−1 from spore-seeded ropes and vegetative fragments was recorded, respectively, well for the first 60 days of culture. Thereafter, the ropes had a significantly higher productivity with a yield of 870 g m−1. Spore-originated thalli had a 50 % lower growth rate than the field-collected thalli under raft technique; however, no significant differences were detected in the field. It was concluded that spore-originated cultivation techniques could be of interest for Gracilaria culture. The methods resulted in greater adaptability to environmental variations and a continuous supply of restocking material.