The viability of red alga (Gracilaria salicornia) seaweed farming for commercial extraction of agar at kibuyuni in kwale county South Coast Kenya

Abstract

This experimental study investigated the growing and viability of the red seaweed Gracilaria salicornia for commercial extraction of agar; which has varied industrial uses. The study was carried out from January to December 2017 in Kibuyuni, South Coast Kenya, using the 'off-bottom' seaweed farming method. G. salicornia can withstand hash environmental factors unlike Kappaphycus alvarezii species, which was introduced in the area and failed to meet the livelihood needs of the communities. The seed yield, daily growth rate (DGR) and agar yield of G. salicornia were determined during the culture period and compared between three sampling sites and between the two monsoonal seasons. The statistical analyses show that the mean annual seed yield (wet yield rope-1), DGR (%) and agar yield (% dry weight) were generally similar in all the sampling sites and seasons (p>0.05), suggesting that G. salicornia can be grown throughout the year at Kibuyuni.