GROWTH RESPONSE OF Kappaphycus alvarezii OF GREEN STRAIN SEAWEED CULTIVATED ON DIFFERENT SEASONS AND LOCATIONS IN INDONESIA

Seaweed is one of the Indonesian commodity exports, which is mostly obtained from the cultivation activities. The seaweed cultivation activity is commonly performed by the coastal community in coastal area using a longline method. There are several problems occured in the coastal area, such as land usage conflict, high pollutant, and sedimentation that affects the cultivated seaweed. Offshore area is an alternative location for seaweed cultivation to provide better water quality for supporting the seaweed growth. This study was aimed to compare the absolute and specific growth rate of seaweed cultivated at inshore and offshore locations, examine the optimum growth rate of seaweed, and determine the maximum growth rate of seaweed cultivated on different seasons. This study was conducted at Punaga Village for one year (2018) using a long line method. We cultivated the Kappaphycus alvarezii green strain at two different locations, i.e inshore and offshore location for one year round. We measured the parameters three times for each season comprising transitional seasons (Apr – May and Oct – Nov) and dry season (beginning (May – July), peak (July – August) and end (August - Oct)). Parameters measured were the absolute and specific growth rate, as well as the water quality (nitrate, phosphate, ammonium, CO2, calcium and magnesium). The results showed that the growth rate of seaweed and concentration of nitrate, CO2 and calcium were higher at the inshore location than at the offshore location. Meanwhile, the offshore location showed high phosphate and magnesium concentration.