The recovery of coral cover is expected to take a decade or longer, scientists say
At least 35% of
corals in the northern and central parts of Australia's Great Barrier
Reef have been destroyed by bleaching, Australian scientists say.
The
experts from James Cook University (JCU) say it is the most extreme
case of mass bleaching they have ever measured at the World Heritage
Site.Bleaching occurs when warmer water causes coral to weaken and lose the colourful algae that provide oxygen and nutrients.
It has been linked to climate change.
"We found on average, that 35% of the corals are now dead or dying on 84 reefs that we surveyed along the northern and central sections of the Great Barrier Reef, between Townsville and Papua New Guinea," Professor Terry Hughes, the head of the ARC Centre of Excellence for Coral Reef Studies at JCU, said in a statement.
"This year is the third time in 18 years that the Great Barrier Reef has experienced mass bleaching due to global warming, and the current event is much more extreme than we've measured before.
"We're rapidly running out of time to reduce greenhouse gas emissions."
The Great Barrier Reef is the world's largest living structure and can be seen from space.
The scientists warned that the recovery of coral cover is expected to take a decade or longer, but it would take much longer to regain the largest and oldest corals that have died.
Their study was released after months of intensive aerial and underwater surveys.
Mass coral bleaching
- Coral bleaching is caused by rising water temperatures resulting from two natural warm currents
- It is exacerbated by man-made climate change, as the oceans are absorbing about 93% of the increase in the Earth's heat
- Bleaching happens when corals under stress drive out the algae known as zooxanthellae that give them colour
- If normal conditions return, the corals can recover, but it can take decades, and if the stress continues the corals can die
- The current worldwide bleaching episode is predicted to be the worst on record
Leo May 29, Mbwana Samatta ameandika historia mpya kwenye maisha yake baada ya
kuisaidia timu yake ya Genk kushinda mchezo wa fainali ya play off na hatimaye kufu kucheza michuano ya Ulaya (Europa League).
Samatta ambaye alianza kwenye kikosi cha kwanza cha Genk ameisaidia
klabu yake kupata ushindi wa magoli 5-1 kwenye uwanja wao wa nyumbani
(Cristal Arena) dhidi ya Sporting Charleroi.
Katika ushindi huo wa magoli 5-1, Samatta amefunga goli moja ambalo
lilikuwa ni goli la pili kwenye mchezo huo. Nikolaos Karelis ambaye
amfunga hat-trick kwenye mchezo huo alianza kuifungia Genk goli la
kwanza kwa mkwaju wa penati dakika ya 17 kisha Samatta akazamisha bao la
pili dakika ya 27 kabla ya Sandy Walsh kupiga bao la tatu dakika ya 45
na kuipeleka Genk mapumziko ikiwa mbele kwa magoli 3-1.
Kipindi cha pili Karelis aliongeza bao la nne dakika ya 56 kisha
kukamilisha hat-trick yake dakika ya 71 kwa kufunga bao la tano.
Mchezo huo ulikuwa ni wa marudiano, mchezo wa awali Genk walipoteza kwa
bao 2-0 kwa maana hiyo hiyo Genk wamefuzu kucheza michuano ya Europa
ligi kwa matokeo ya jumla 5-3.
Genk itaanzia kwenye hatua ya awali ya mtoano kabla ya ile ya makundi, kama watafuzu basi watapangwa kwenye hatua ya makundi.
- See more at: http://darubiniyako.blogspot.nl/2016/05/samatta-aipeleka-genk-europa-league.html#sthash.44xgWf4r.dpuf
Leo May 29, Mbwana Samatta ameandika historia mpya kwenye maisha yake baada ya
kuisaidia timu yake ya Genk kushinda mchezo wa fainali ya play off na hatimaye kufu kucheza michuano ya Ulaya (Europa League).
Samatta ambaye alianza kwenye kikosi cha kwanza cha Genk ameisaidia
klabu yake kupata ushindi wa magoli 5-1 kwenye uwanja wao wa nyumbani
(Cristal Arena) dhidi ya Sporting Charleroi.
Katika ushindi huo wa magoli 5-1, Samatta amefunga goli moja ambalo
lilikuwa ni goli la pili kwenye mchezo huo. Nikolaos Karelis ambaye
amfunga hat-trick kwenye mchezo huo alianza kuifungia Genk goli la
kwanza kwa mkwaju wa penati dakika ya 17 kisha Samatta akazamisha bao la
pili dakika ya 27 kabla ya Sandy Walsh kupiga bao la tatu dakika ya 45
na kuipeleka Genk mapumziko ikiwa mbele kwa magoli 3-1.
Kipindi cha pili Karelis aliongeza bao la nne dakika ya 56 kisha
kukamilisha hat-trick yake dakika ya 71 kwa kufunga bao la tano.
Mchezo huo ulikuwa ni wa marudiano, mchezo wa awali Genk walipoteza kwa
bao 2-0 kwa maana hiyo hiyo Genk wamefuzu kucheza michuano ya Europa
ligi kwa matokeo ya jumla 5-3.
Genk itaanzia kwenye hatua ya awali ya mtoano kabla ya ile ya makundi, kama watafuzu basi watapangwa kwenye hatua ya makundi.
- See more at: http://darubiniyako.blogspot.nl/2016/05/samatta-aipeleka-genk-europa-league.html#sthash.44xgWf4r.dpuf
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