Ukuphela kungase kusondele eGreat Barrier Reef

Isakhiwo samanje esiphilayo se- I-Great Barrier Reef ihlangabezane nokufiphala okune eminyakeni engu-19. Ukushisa kwenzeka lapho izinga lokushisa lamanzi likhuphuka futhi i-coral ixosha ulwelwe oluhlala phakathi kwawo, lukhipha umbala walo. Iwuhlelo olukhulu kunazo zonke emhlabeni lwe-coral reef futhi ineminyaka engaphezu kuka-8,000 ubudala, noma kunjalo isikhathi saso sibonakala siphela . Ibizwe ngokuthi Igugu Likazwelonke Lase-Australia kanye nesipiliyoni sakanye ekuphileni kwabavakashi, futhi manje, mhlawumbe ngenxa yesizathu esihlukile. 

A cwaningo, olwenziwa i-ARC Center of Excellence for Coral Reef Studies, likhishwe ngoMashi lichaza ubukhulu bomonakalo ku-Great Barrier Reef ngesikhathi sokufiphala okuphindelelayo ngo-1998, 2002, nango-2016. Idatha yakamuva evela kuhlolovo lwango-2017 ibonisa ukuthi i-reef usephakathi komunye umcimbi wokufiphala.  

Isimo se-reef singase singabi ukuphela okwamanje ngokoMqondisi Wesikhungo Se-ARC, kodwa amakhorali akhula ngangamayintshi angu-0.1 ngonyaka futhi ngisho namakhorali akhula ngokushesha angathatha ishumi leminyaka ukuze abuyele empilweni ephelele. Ama-bleaching amabili okugcina enzeka kuphela izinyanga eziyi-12 ngokuhlukana, anganikezi ithuba lokutholwa kwamakhorali alinyazwa ngo-2016.  

Amakhorali afinyelela umbala wokukhanya ngolwelwe, anobudlelwane nabo be-symbiotic. I-Coral ihlinzeka ngendawo yokukhosela ulwelwe nezinhlanganisela ze-photosynthesis. Ngakolunye uhlangothi, i-algae isiza i-coral ukususa udoti, futhi inikeza i-coral umoya-mpilo nama-carbohydrate ayikhiqizayo kusuka ku-photosynthesis. Ulwelwe lushiya ikhorali ukuthi lizinakekele lapho licindezelwe ngenxa yezinto ezihlukahlukene ezifana namanzi afudumalayo, ukukhanya kwelanga okugqame kakhulu, noshintsho kusawoti. Ikhorali liphenduka mhlophe noma “libhujiswe.” Ulwelwe lungabuya lapho amanzi ephola , kodwa uma lokho kungenzeki, khona-ke i-coral iyafa. 

Ucwaningo, oluqoqe idatha ngezinhlolovo zasemoyeni nezamanzi, zinezinombolo ezishaqisayo mayelana nalokhu kufa kwamakhorali. Ngo-1998 nango-2002, cishe amaphesenti ayishumi ezixhobo zokusebenza ezahlolwa zaba nokumhlophe okukhulu. Ngo-2016, amaphesenti angu-90 ake athintwe ukufiphala ngamaphesenti angu-50 ezixhobo zokusebenza ezibe nokumhlophe okukhulu.  

Ucwaningo luphinde lubonise ukuthi izixhobo azijwayelani namanzi afudumalayo. Izinto eziwubuwula zabola ngaphambi kokuba zibe mhlophe ngendlela embi ngokuzayo lapho zenzeka.  

Ukubikezelwa komhlaba wonke kwezixhobo zama-reef kubi futhi, ngochwepheshe abaqaphela ukuthi izixhobo njengoba sazi ngeke zibuyele ezakhiweni zazo zokucwiliswa kwama-pre-bleaching ngokuba mhlophe kube yinto yomhlaba wonke. Kufika kumaphesenti angu-70 ezixhobo zamakhorali zomhlaba angase alahleke ngo-2050.  

Ochwepheshe baphethe ngokuthi ukufiphala kwenzeka ngenxa yokushintsha kwesimo sezulu. I-bleaching mass yatholwa okokuqala engxenyeni yokugcina yekhulu lama-20 , okuhambisana ukufudumala okubonakalayo kwesimo sezulu soMhlaba ngenxa yamagesi abamba ukushisa. Ngaphambi kwalokho, ukukhishwa kwe-bleaching kwakuwumcimbi wendawo kuphela owawuvame ukwenzeka phakathi namagagasi aphansi kakhulu.