Rising ocean temperatures and ocean acidity may deliver a deadly one-two punch to the world’s corals. Holger Anlauf placed coral larvae and young corals under four controlled culture conditions: (1) increased temperatures (2) increased acidity (3) combination of both and (4) control condition i.e. no change. Our levels of acidity and temperature are conservative estimates for the worlds oceans in 100 years time.
We found from Holger’s ground-breaking experiment that early coral growth was reduced only marginally when exposed to more acidic seawater but when exposed to both acidic and higher temperatures the growth of corals fell by almost a third.
The better news is the survival of coral larvae were generally unaffected by the predicted conditions.
These results indicate that in future scenarios of increased temperature and oceanic acidity corals will still be able to disperse successfully but their early growth may be severely hampered.
The recovery of reefs may therefore be impeded by global change even if local stressors are curbed and sufficient sources of larvae are available.
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