Growth Rate of the Seaweed Kappaphycus alvarezii and the Pacific White Shrimp Litopeneaus vannamei in Polyculture Intensive Ponds for Seed Seaweed Availability

The culturing activity of Kappaphycus alvarezii is generally performed in coastal areas.  This method has been used for many years and is still utilized. The number of seaweed farmers increases every year. This can lead to a conflict of interest among the farmers because since seaweed needs a specific location for its growth.  Hence, the best solution must be considered to avoid the potential conflict in coastal spatial utilization among farmers.  One method that can be developed to sustain seaweed cultivation is to relocate the area from coastal to pond polyculture.  In this context, this research aimeds to study the performance of the K. alvarezii polyculture with the white leg shrimp Litopennaeus vannamei in intensive ponds. The research was done at the Culture Unit, Agriculture Polytechnic from Pangkep State, South Sulawesi Province, from June to August 2022.  The quasi-experiment method was used.  The pond size was 20x40 m.  K. alvarezii was using cultivated using the long line method.  There were 10 lines with 120 points for each line, and the distance for each point was 25 cm. At each point, around 100g of K. alavarezii was hanged. The sStocking density was 15 ind/ m² or 12.000 individuals per pond (PL-12). Rearing was done for 42 days for K. alvareziii and 60 days for L. vannamei.  L. vannamei was fed three times a day, and detritivore bacteria were fed once a week.  Special growth rate and water qualities were measured. The rResults showed that the specific growth rate of K. alvarezii rangeeds from 3.70- 3.75% per day, showing a good daily growth. The specific growth rate of L. vannamei rangedes from 4.,18- 4.,38% per day. Water qualities during the research were in a range that still could be tolerant by K alvarezii and L. vannamei: with 30- 37ppm for salinity, nitrate 0.,15-  2.,14ppm for nitrate, 0.,32- 0.,51ppm for phosphate, and ranges of temperature from 30- 33°C, dissolved oxygen 5.,79- 6.,7 ppm, and pH 6.,9- 7.,1.  K alvarezii polyculture with L. vannamei showeds a better specific growth rate than K alvarezii monoculture.