View source for Ice-ice

{{Short description|Disease condition of seaweed}}
{{distinguish|Ice|Ice Ice Baby}}
[[File:Ice-ice disease on Kappaphycus.jpg|thumb|right|''[[Kappaphycus]]'' sp. with ice-ice]]
'''Ice-ice''' is a disease condition of [[seaweed]]. Ice-ice is caused when changes in [[salinity]], [[Sea surface temperature|ocean temperature]] and [[irradiance|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.<ref name="dost">[http://sntpost.stii.dost.gov.ph/frames/jantomar04/pg27b.htm DOST.gov.ph:]</ref> Bacteria involved include those in the ''[[Vibrio]]-[[Aeromonas]]'' and ''[[Cytophaga]]-[[Flavobacteria]]'' complexes.<ref name=hurtado>{{cite journal|last1=Hurtado|first1=A. Q.|last2=Critchley|first2=A. T.|last3=Trespoey|first3=A.|last4=Lhonneur|first4=G. B.|title=Occurrence of ''Polysiphonia'' epiphytes in ''Kappaphycus'' farms at Calaguas Is., Camarines Norte, Philippines |journal=Journal of Applied Phycology|date=8 July 2006|volume=18|issue=3–5|pages=301–306|doi=10.1007/s10811-006-9032-z|s2cid=19366858 }}</ref> The bacteria [[lysis|lyse]] [[epidermis (skin)|epidermal cells]] and [[chloroplast]]s, turning the seaweed tissue white.<ref name=hurtado/> The disease is known from seaweeds including ''[[Kappaphycus cottonii|Kappaphycus alvarezii]]'' and ''[[Eucheuma denticulatum]]'', economically important sources of [[carrageenan]].<ref name=hurtado/><ref>{{cite journal|last1=Largo|first1=D. B.|last2=Fukami|first2=K|last3=Nishijima|first3=T|last4=Ohno|first4=M|title=Laboratory-induced development of the ice-ice disease of the farmed red algae ''Kappaphycus alvarezii'' and ''Eucheuma denticulatum'' (Solieriaceae, Gigartinales, Rhodophyta)|journal=Journal of Applied Phycology|date=December 1995|volume=7|issue=6|pages=539–543|doi=10.1007/BF00003940|s2cid=19073993 }}</ref> In countries where seaweed is harvested as a crop, ice-ice can wreak havoc on yields. [[Zamboanga Peninsula|Zamboanga]], Philippines, had an outbreak of ice-ice in 2004,<ref name="dost"/> and [[Bali]], Indonesia, experienced an outbreak in 2009.<ref name=jak>[http://www.thejakartapost.com/news/2009/10/28/rising-sea-temperatures-bad-news-seaweed-farmers.html JakartaPost: Rising sea temperatures bad news for seaweed farmers]</ref> A rise in surface sea temperatures of 2–3 degrees Celsius can trigger ice-ice outbreaks.<ref name=jak/>
__TOC__
==Pathogens==
Analysis has been performed to determine the pathogens affecting the ''[[Gracilaria verrucosa]]'' and ''[[Kappaphycus alvarezii]]'' seaweeds. Morphologic and phenotypic characteristics (16s RNA analysis) showed that the isolates from diseased ''Gracilaria'' belong to various genera: ''[[Vibrio]], [[Chromobacterium]], [[Flavobacterium]], [[Pseudomonas]]'', and ''[[Achromobacter]]''.<ref name=":0">{{Cite journal |last=Zainuddin |first=Elmi Nurhaidah |last2=Anshary |first2=Hilal |last3=Huyyirnah |first3=Huyyirnah |last4=Hiola |first4=Ridha |last5=Baxa |first5=Dolores V. |date=2019-10-01 |title=Antibacterial activity of Caulerpa racemosa against pathogenic bacteria promoting “ice-ice” disease in the red alga Gracilaria verrucosa |url=https://doi.org/10.1007/s10811-019-01805-w |journal=Journal of Applied Phycology |language=en |volume=31 |issue=5 |pages=3201–3212 |doi=10.1007/s10811-019-01805-w |issn=1573-5176}}</ref> They belong for the most part to the group of [[Gammaproteobacteria]], already well known from disease-related study on seaweeds. For the seaweeds ''[[K. alvarezii]]'' a leading candidate bacterium has been identified: ''[[Stenotrophomonas maltophilia]]''.<ref>{{Cite report |url=https://peerj.com/preprints/2016 |title=Molecular identification of new bacterial causative agent of ice-ice disease on seaweed Kappaphycus alvarezii |last=Achmad |first=Marlina |last2=Alimuddin |first2=Alimuddin |date=2016-05-03 |publisher=PeerJ Preprints |issue=e2016v1 |language=en |last3=Widyastuti |first3=Utut |last4=Sukenda |first4=Sukenda |last5=Suryanti |first5=Emma |last6=Harris |first6=Enang}}</ref> In most cases it seems these microorganisms are opportunistic pathogens. Some treatments have been investigated to cure these ice-ice infections, the [[green algae]] ''[[Caulerpa racemosa]]'' seems to inhibit the action of the most part of these pathogens.<ref name=":0" />
==Effects==
The disease seems to affect the formation of [[micropropagule]] of the algae. The protoplasm content is higher in a healthy micropropagule than in the infected ones. Protoplasm indicates occurrence of severe chronic infections of the micropropagules (algae disease are characterized by reduced number of cell [[protoplasm]]<ref>{{Cite journal |last=Quéré |first=Gaëlle |last2=Meistertzheim |first2=Anne-Leila |last3=Steneck |first3=Robert S. |last4=Nugues |first4=Maggy M. |date=2015-06-30 |title=Histopathology of crustose coralline algae affected by white band and white patch diseases |url=https://peerj.com/articles/1034 |journal=PeerJ |language=en |volume=3 |pages=e1034 |doi=10.7717/peerj.1034 |issn=2167-8359|doi-access=free |pmc=4493676 }}</ref>).
== References ==
{{reflist}}
[[Category:Bacterial plant pathogens and diseases]]