Coral ‘bright spots’ offer clues to protecting threatened reefs

Jun 21, 2016

By Alister Doyle

Some coral reefs are thriving and scientists say they may guide efforts to curb threats such as over-fishing and climate change which are blamed for widespread global declines.

A major study identified 15 “bright spots” among more than 2,500 coral reefs in 46 nations, including off Indonesia, the Solomon islands and Kiribati where given local stresses there were far more fish than predicted.

And the Great Barrier Reef off Australia, the world’s biggest, was performing in line with expectations given its remoteness and high level of protection, lead author Joshua Cinner, a professor at James Cook University in Australia, told Reuters of the study published on Wednesday in Nature.


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3 comments on “Coral ‘bright spots’ offer clues to protecting threatened reefs

  • @OP – link – Australian Prime Minister Malcolm Turnbull, facing a tight re-election battle, on Monday pledged an A$1 billion ($740 million) fund for the reef, which scientists say is suffering widespread coral bleaching due to climate change.

    If damage is due to pollution, over-fishing, or other human abuse, proper management could give improvements.

    If bleaching is due to climate change and periodic heating, some corals are likely to face extinction – with the implications that hold for communities dependent on them for food or coastal protection from erosion and storms.

    There are however some more heat resistant corals and algal symbionts, in the Red Sea.

    http://www.natureasia.com/en/nmiddleeast/article/10.1038/nmiddleeast.2015.57
    Red sea coral reefs may be more tolerant to heat than other coral reefs around the world, but climate change may be straining their tolerance to its limit.
    Corals from the different sites were genetically similar and showed a strongly consistent relationship between calcification and temperature, indicating that a homogeneous P. verrucosa population spans the Red Sea, rather than several sub-populations adapted to their local conditions.

    The study showed that corals in the south of the Red Sea, where temperatures are higher, are at the edge of their tolerance. The findings are an alarm call for the impact of global warming on these corals, according to Maren Ziegler, a researcher at KAUST who was not involved in the study.

    Yvonne Sawall, the lead author of the study said that given the steep temperature gradient and the large distances involved, she expected to find local adaptation, with genetic divergence and site-specific calcification dependent on temperature, rather than such a homogeneous picture. Sawall, however, cautions that the team only examined variation at neutral genetic loci, and further studies may uncover variation at other loci.

    The team did find some variation in the symbiotic algae associated with the corals in the northernmost and southernmost samples. “Maybe the new algae species we discovered in the south is particularly thermo-tolerant,” said Sawall.

    While these corals are more heat tolerant than many elsewhere, they and their algae, are under pressure in the hottest waters of the Red Sea.



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  • @OP – Some coral reefs are thriving and scientists say they may guide efforts to curb threats such as over-fishing and climate change which are blamed for widespread global declines.

    Where human activities are responsible for reef damage and depletion of fish stocks, protective measures may be effective in protecting food supplies and coastlines.

    Where climate change is responsible there are however some areas where some coral and symbiont algae are more heat tolerant than most, but even some of these are under pressure.

    http://www.natureasia.com/en/nmiddleeast/article/10.1038/nmiddleeast.2015.57

    Red sea coral reefs may be more tolerant to heat than other coral reefs around the world, but climate change may be straining their tolerance to its limit.

    Corals from the different sites were genetically similar and showed a strongly consistent relationship between calcification and temperature, indicating that a homogeneous P. verrucosa population spans the Red Sea, rather than several sub-populations adapted to their local conditions.

    The study showed that corals in the south of the Red Sea, where temperatures are higher, are at the edge of their tolerance. The findings are an alarm call for the impact of global warming on these corals, according to Maren Ziegler, a researcher at KAUST who was not involved in the study.

    Yvonne Sawall, the lead author of the study said that given the steep temperature gradient and the large distances involved, she expected to find local adaptation, with genetic divergence and site-specific calcification dependent on temperature, rather than such a homogeneous picture. Sawall, however, cautions that the team only examined variation at neutral genetic loci, and further studies may uncover variation at other loci.

    The team did find some variation in the symbiotic algae associated with the corals in the northernmost and southernmost samples. “Maybe the new algae species we discovered in the south is particularly thermo-tolerant,” said Sawall.

    Indentifying a difference associated with temperature tolerance would encourage researchers who are concerned about the impact of global warming on corals and the ecosystems they support. Sawall’s team is also planning a follow-up study to look for signs of local adaptation in another coral species is not as well dispersed as P. verrucosa.



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