Ice-ice
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]
References
- ^ a b DOST.gov.ph:
- ^ a b c Hurtado, A. Q.; Critchley, A. T.; Trespoey, A.; Lhonneur, G. B. (8 July 2006). "Occurrence of Polysiphonia epiphytes in Kappaphycus farms at Calaguas Is., Camarines Norte, Philippines". Journal of Applied Phycology. 18 (3–5): 301–306. doi:10.1007/s10811-006-9032-z.
- ^ Largo, D. B.; Fukami, K; Nishijima, T; Ohno, M (December 1995). "Laboratory-induced development of the ice-ice disease of the farmed red algae Kappaphycus alvarezii and Eucheuma denticulatum (Solieriaceae, Gigartinales, Rhodophyta)". Journal of Applied Phycology. 7 (6): 539–543. doi:10.1007/BF00003940.
- ^ a b JakartaPost: Rising sea temperatures bad news for seaweed farmers