SEAWEED SELECTION FOR GROWTH ENHANCEMENT OF Kappaphycus striatum TO PRODUCE SEED FOR CULTIVATION

Andi Parenrengi*, Mat Fahrur, Makmur, and Sri Redjeki Hesti Mulyaningrum
 
Research Institute for Coastal Aquaculture, South Sulawesi, Indonesia, 90511
Agency for Marine and Fisheries Research and Development
andi_parenrengi@hotmail.com
 

Seaweed cultivation in Indonesia has rapidly expanded following demands of seaweed as industrial raw materials for both domestic and export markets.  Kappaphycus striatum, one of the commercial eucheumatoid seaweed species, has been intensively cultivated in the coastal waters. Since 2011, Indonesia has become a leader of the eucheumatoid seaweed production in the world. Indonesia's seaweed production in 2013 reached 9,298,474 MT compared with seaweed production of the Philippines which was 1,558,378 MT and that of Malaysia which was 269,431 MT (FAO, 2015). To date, one of the problems faced by seaweed farmers is low seed quality from cultivated seaweed. This condition will decrease the growth and production of seaweed. To overcome the problem, strain selection should be performed to get better growth of seaweed for cultivation. The present study was conducted to determine the effect of seaweed selection on growth rate of K. striatum.

Seaweed K. striatum was cultivated at Laikang Bay, Takalar Regency, South Sulawesi Province in 2014 using long line method. Seaweed selection was carried out based on growth rate parameter and selection protocol was conducted based on trial funded by Government of Indonesia (Pongmasak et al., 2011). To produce seed, seaweed was cultivated for 30 days a cycle and then the best ten percent of growth was selected for the next cultivation. The seed without selection was used as control treatment. Cultivation was performed for three cycles in order to get stable growth.

The result of study showed that daily growth rate (DGR) of selected seaweed was significantly higher than control (P<0.05), in which DGR of seed from selected seaweed reached to 3.47%/day while DGR of seed from control was 1.81%/day (Figure 1). The highest DGR was obtained at cycle-3 of cultivation for both selected and control seaweed. The carrageenan content of K. striatum during the cultivation (cycle-1 to 3) showed slight difference between carrageenan content of selected seaweed with that of control. The highest carrageenan content of selected seaweed (32.04%) was obtained at cycle-2 and the carrageenan content of control (30.25%) occurred in cycle-2 (Table 1). Selected seaweed K. striatum showed higher gel strength of carrageenan compared with gel strength of carrageenan of the control seaweed from cultivation cycle-1 to cycle-3 with average of 539.52 and 455.29 g/cm2, respectively. The highest gel strength of selected seaweed was 636.42 g/cm2 while gel strength of carrageenan of the control seaweed was only 559.84 g/cm2 (Table 1). Results of the present study suggested that implementing seaweed selection procedure will potentially enhance seaweed growth rate to produce seed for cultivation.