Growth and carrageenan content of red algae, Kappahycus alvarezii (doty) doty different varieties farming using different methods and different habitats in Bolok waters, Kupang Regency Available to Purchase

Red algae (Rhodophyceae) Kappaphycus alvarezii is a species of macroalgae/seaweed that produces kappa-carrageenan which is intensively used in many industries. K. alvarezii is currently a leading commodity in the province of NTT because it makes a significant contribution to the income of the community and the region. The growth and content of carrageenan are strongly influenced by environmental conditions, especially related to farming habitat. The aimed of the study were to analyze the growth and carrageenan content of K. alvarezii different varieties cultured using different method and different habitat. For growth data, samples were taken every 7 days for 49 days (7 weeks), for each variety, method, and habitat. Sampling was carried out with 3 (three) replications for each treatment, by taking as many as 15 bonds at random. The initial weight of the seeds used was 100 gr. For carrageenan content, dry samples were taken at random from the 49-day-old K. alvarezii harvested. Each treatment (variety, method, and habitat) was taken with 3 (three) replicates at random. The results showed that for growth, varieties of Sacol Semau and Tissue culture Rote gave better specific growth compared to the other. The plants farmed using the longline method in the sand habitat gave better growth. for carrageenan, the Tambalang green variety from tissue culture from Semau gave the highest value, namely 56.71%. longline method. For different habitats, K. alvarezii cultivated in sand habitats gave higher carrageenan content (an average of 55.15%) than in seagrass habitats. The ANOVA results showed that in terms of growth, K. alvarezii cultivated in sand habitat showed higher very significantly different (p≤0.05; p≤0.01), compared to the one with seagrass habitat; while in terms of carrageenan contents, the interaction between different varieties cultivated with different methods and habitats showed no significant effect (p≤0.05; p≤0.01).