This Fish Could Save the Caribbean Coral Reefs

The International Union for Conservation of Nature has released a massive report on the health of Caribbean coral reefs. Based on data collected from 35,000 surveys spanning 42 years, it is the most comprehensive study on the reefs ever published.

The bad news is that coral reefs are declining at a breakneck pace. Only a sixth of the structure’s original range has survived the last few decades, and it may take only 20 years to edge out the remaining reefs.

The good news is that there may be a very simple answer: don’t kill parrotfish. The study found that these keystone herbivores disproportionately contribute to the health of their host reefs by feeding on coral-suffocating algae.

The IUCN cited the declining parrotfish population, as well as other algae grazers like sea urchins, as the key driver behind reef collapse. It even trumps the negative effects of climate change on tropical reefs, though that may change over the coming decades.

“Even if we could somehow make climate change disappear tomorrow, these reefs would continue their decline," Jeremy Jackson, lead author of the report and IUCN’s senior advisor on coral reefs, said in a release. "We must immediately address the grazing problem for the reefs to stand any chance of surviving future climate shifts.”

In any case, the news offers a glimmer of hope. Because climate change is unlikely to be vanquished in the two decades these reefs have left, comparatively, protecting algae-eaters should be a piece of cake.

Yet there is often a knee-jerk cynical response to these kinds of stories from the public. It is embodied by the top Reddit comment on the IUCN story about how simply the reef damage can be reversed.

“Can, but won’t,” said Redditor Angeldust01. “At least for now. It costs money and won’t bring profits.”

Sure, it’s Reddit, one of the Internet’s greatest bastions of indiscriminate defeatism. It should be taken with a pillar of salt. But the comment does sum up the attitude many people have about the daily onslaught of bad environmental news. Maybe that’s why it was the thread’s top comment, despite more optimistic responses further down.

Indeed, the fact that there may be a simple answer to this particular conservation problem almost makes it more excruciating. What if humans can’t even get around to protecting one measly species and accordingly lose an entire ecosystem, one that comprises almost a full tenth of the world’s coral reefs? That sounds like something we might do.

Ocean activists must be keenly aware of the public reticence to be optimistic about conservation, and they often specifically call it out. For example, Ayana Johnson, one of the 90 authors of the IUCN report, summarized the findings on NatGeo.com.

“This may sound hopeless, but it’s far from it!” she wrote, and then later on concluded, “Here’s to hoping 2014 continues to be a year of strong action for ocean conservation.” “Hope” has become a necessary cheerleading word in pro-conservation articles. And the hashtag Johnson recommended for continued coverage of the story was #OceanOptimism.

Both optimism and pessimism are valid responses to the IUCN report, and the future of the reefs will no doubt validate each reaction to some extent. Fortunately, Johnson has already overseen one big success story on the island of Barbuda, which is poised to ban catching parrotfish and other grazers, and will earmark a third of its coastal waters for marine reserves.

“This is the kind of aggressive management that needs to be replicated regionally if we are going to increase the resilience of Caribbean reefs,” said Johnson in the IUCN press release.

To borrow the word of the hour, let’s hope that it is replicated far and wide. Pessimists could use a little less fodder for their viewpoints, and optimists could use a little more.