Identification and determination of optimum growth condition with respect to selected environmental parameters for open sea cultivation of Gracillaria edulis in Andaman water

Gracilaria edulis is one of India's most widely cultivated seaweeds. Pilot scale cultivation of Gracilaria edulis was initiated at Andaman, India for the first time. In the present study attempt has been made to identify how different water quality parameters influence the growth. Total 11 physicochemical parameters and 9 microbiological parameters, as well as chlorophyll and zooplankton, phytoplankton parameters were studied for two different seasons to evaluate which parameters influence seaweed growth. Six (nitrate, nitrite, ammonia, silicate, chlorophyll, photosynthetic active radiation) have a positive impact on seaweed growth, while some of the bacterial species showed negative impact. Lowess 3D curve fit model showed pH range from 7.59 to 7.82, N/P ratio of 2.046, rainfall 23.85-24 mm, and Photosynthetic active radiation of 376.6 W/m2 are optimum for Gracillaria growth. This model can be applied to future mass culture.

Automated summary

The present study aimed to identify the influence of different water quality parameters on the growth of Gracilaria edulis. It was found that six physicochemical parameters had a positive impact on growth, while some bacterial species had a negative impact. A Lowess 3D curve fit model was established to determine the optimal pH range, N/P ratio, rainfall, and photosynthetic active radiation for mass cultivation.