A case for evidence-based reef conservation

Like forests formed by trees, tropical coral reefs are built up by corals over thousands of years via the slow accumulation of their skeletons. Corals – related to jellyfishes and sea anemones – provide shelter to countless other species, including the fishes we travel to see and love to eat.

But corals and coral reefs are in trouble. We’ve lost at least two thirds of the world’s reef-building corals over the last few decades, mainly due to ocean warming. About 90% of the additional heat being trapped on earth by greenhouse gases goes into the ocean. This causes reefs to warm, leading to disease outbreaks and coral bleaching.

An ineffective solution

The most common response by policy makers and reef managers to coral decline is to ban fishing. The idea is that fishing indirectly exacerbates ocean warming by enabling seaweeds that suffocate corals. More generally, the approach is based on the assumption that threats to species and ecosystems are cumulative: by minimizing as many as possible, we can make ecosystems “resilient” to climate change and other threats that cannot be addressed locally.

Unfortunately, there is now an overwhelming body of evidence that this approach, called “managed resilience” by conservation scientists, doesn’t work. At least for coral reefs. This is the key finding of our new study published in the Annual Review of Marine Science.

We performed a meta-analysis: a systematic review of 18 case studies that field-tested the effectiveness of the managed resilience approach. None found that it was effective. Protecting reefs inside Marine Protected Areas (MPAs) did not reduce how much coral was killed by extreme temperatures related to global warming or how quickly threatened coral populations recovered.

The 18 individual studies compared the impact of large-scale disturbances (mass bleaching events, major storms, and disease outbreaks) inside MPAs to unprotected reefs. Many also measured the rate of coral population recovery after disturbances. Overall, the meta-analysis included data from 66 protected reefs and 89 unprotected reefs from 15 countries around the world. No form of local protection, include large-scale fishing bans on some of the world’s most isolated reefs, had any effect on how much coral was killed off by climate change. Fisheries restrictions, while clearly beneficial for over-harvested species, don’t help reef-building corals cope with human-caused climate change.

We currently devote much of our conservation budget towards a solution we know isn’t effective. Billionaires like Michael Bloomberg have been giving NGOs millions to expand managed resilience. The United States government’s new plan to save reefs is based on it. So is Australia’s plan for managing the Great Barrier Reef. (Notably neither plan prioritizes greenhouse gas emissions or climate change.)

Why do we embrace ineffective “managed resilience”?

There are probably many reasons for the widespread acceptance of managed resilience in reef conservation. Most obviously, it blames and puts the burden of change on other people. Instead of not flying, driving, eating meat, etc., scientists and managers in the US, Australia, Canada, and Europe (nearly all Caucasian) can implement policies that demand sacrifice of people they’ll never meet: mainly poor, non-white fisherman and their families. Such neocolonialist thinking in reef management almost feels like a form of white supremacy.

Managed resilience also fits the universal storytelling frame of the villain and the hero. In this case, the villain is seaweed that purportedly overgrows hapless corals, and the heroes are fishes that eat it, protecting corals, and making reefs resilient to disturbances. Yet the reality is that seaweed blooms are usually a result of coral mortality and a general symptom of reef degradation, rather than the cause of it.

Managed resilience can also be highly lucrative. Foundations, federal agencies, and especially billionaires love resilience thinking: tackling a global problem without any lifestyle changes! The funds pour in to the labs and NGOs willing to go down this path. One group was recently awarded 444 million dollars by the Australian government to save the Great Barrier Reef (as long as saving it doesn’t mean reducing coal exports or addressing climate change). Such awards typically sidestep peer review and other scientific norms designed to ensure accountability, effectiveness, and scientific rigor.

Finally, attempting to manage the impacts of global warming on reefs via local conservation efforts is widely seen as doing something – anything to help slow the loss.

A sea of ineffective solutions

Whether its straw and sunscreen bans or expensive contraptions designed to scoop up garbage, marine conservation is now dominated by displacement activities: ineffective actions that make us feel like we’re doing something to protect the biodiversity of the oceans. Rather than tackling the big problems like carbon emissions head on, we devise pseudo solutions that require only minor inconvenience instead of fundamental societal change (e.g., curbside recycling instead of reduced consumption and getting by without straws instead of switching to renewable energy sources).

Managed reef resilience fits firmly within the sea of displacement activities now favored by many NGOs and conservation scientists. We’re told these “gateway” activities will eventually lead to more meaningful change. Yet in the meantime, they are taking up much of the funding and media coverage that could be directed towards proven solutions.

A more effective way forward

Many outcome-based fields (e.g., public policy and health care) have adopted a more stringent evidence-based approach to solving problems. The idea is that resource allocation should be based on a stringent evidence standard (primarily on quantitative systematic reviews) rather than dogma and anecdote. Advocates of managed reef resilience often argue that due to the severity of the threat and the shortness of remaining time, we need to just “try anything” regardless of the science. But I’ve been hearing this for over twenty years and it’s gotten us nowhere: there is literally no reef on earth where the coral framework has been locally protected from climate change. Even the world’s most isolated, diverse, and well-managed reefs have succumbed.

A recent survey of international bleaching experts found that an overwhelming majority believe managed resilience works. Clearly, our greatest outreach challenge isn’t convincing the public that reefs are in trouble – its convincing reef scientists, NGOs, and the federal agencies tasked with saving reefs. We need to abandon the false promise of managed resilience and get to work on halting the real driver of reef decline: greenhouse gas emissions. And to achieve that we know exactly what to do.






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