Warming Impedes a Coral Defense, but Hungry Fish Enhance It

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Corals create potions that fight bacterial attackers, but warming appears to tip the scales against the potions as they battle a bacterium common in coral bleaching, according to a new study.

Corals create potions that fight bacterial attackers, but warming appears to tip the scales against the potions as they battle a bacterium common in coral bleaching, according to a new study. Reef conservation may offer hope: A particular potion, gathered from reefs protected against seaweed overgrowth, proved more robust.

The protected Pacific reefs were populated by diverse corals and shimmered with colorful fish, said researchers who snorkeled off of Fiji to collect samples for the study. Oceanic ecologists from the Georgia Institute of Technology compared coral potions from these reefs, where fishing was prohibited, with those from heavily fished reefs, where seaweed inundated corals because few fish were left to eat it.

The medicated solutions, or potions, may contain a multitude of chemicals, and the researchers did not analyze their makeup. This is a possible next step, but here the researchers simply wanted to establish if the potions offered any real defense against pathogens and how warming and overfishing might weaken it.

Read more at Georgia Institute of Technology

Image: At an over-fished Pacific reef, seaweed has taken over, diminishing coral populations to a fraction of what they would be otherwise.  Credit: Georgia Tech / Hay lab