Ice-ice is a disease condition of seaweed. Ice-ice is caused when changes in salinity, ocean temperature and light intensity cause stress to seaweeds, making them produce a "moist organic substance" that attracts bacteria in the water and induces the characteristic "whitening" and hardening of the seaweed's tissues.[1] Bacteria involved include those in the Vibrio-Aeromonas and Cytophaga-Flavobacteria complexes.[2] The bacteria lyse epidermal cells and chloroplasts, turning the seaweed tissue white.[2] The disease is known from seaweeds including Kappaphycus alvarezii and Eucheuma denticulatum, economically important sources of carrageenan.[2][3] In countries where seaweed is harvested as a crop, ice-ice can wreak havoc on yields. Zamboanga, Philippines, had an outbreak of ice-ice in 2004,[1] and Bali, Indonesia, experienced an outbreak in 2009.[4] A rise in surface sea temperatures of 2–3 degrees Celsius can trigger ice-ice outbreaks.[4]
Categories: [Red algae]