Ice-ice disease in commercially cultivated seaweeds Kappaphycus spp. and Eucheuma spp.: A review on the causes, occurrence, and control measures

Abstract

Kappaphycus spp. and Eucheuma spp. are two economically significant seaweed species cultivated globally due to their carrageenan content with numerous commercial applications. They are mainly cultivated in the Philippines, Indonesia, Malaysia, and Tanzania. The culture of these seaweeds also provides income sources for many coastal dwellers. In 2018, the total global production from these seaweeds was about 11 million tonnes. One of the primary problems that affect seaweed production is the incidence of ice- ice disease. In this article, we reviewed the reported scientific journals on the ice-ice disease of two commercially cultured seaweed species (Kappaphycus spp. and Eucheuma spp.), focusing mainly on causes, occurrence, and control measures. The ice-ice disease is caused by both abiotic and biotic factors manifested by the presence of white and soft parts in the infected seaweeds. The occurrence of this disease varies from species, places, and seasons. Control measures may include proper farm management, polyculture with other seaweeds, pre-soaking with antibacterial substances and nutrient enrichment before out-planting, and possibly using genetic engineering.