pristine corals

This guest blog comes from a former KSLOF fellow, Dr. Anderson Mayfield, who joined the foundation on many of our Global Reef Expedition research missions in the Pacific and Indian Oceans. A former student of the renowned coral biologist Dr. Ruth Gates, Dr. Mayfield studies coral health and physiology at NOAA’s AOML Coral Program and at the University of Miami’s Cooperative Institute for Marine and Atmospheric Studies. He continues to publish scientific papers based on data collected on the Global Reef Expedition, including his latest paper, recently published in the journal Oceans.

As a naïve post-doctoral researcher back in 2012, I had an idea that was surely far from novel at the time: corals of far-flung, uninhabited atolls are in better shape than those closer to major human population centers. The logic was that these corals would be under global-scale stressors only (namely those associated with climate change), and not the threats that instead plague reefs close to cities (such as pollution and overfishing).

As a fellow with the Khaled bin Sultan Living Oceans Foundation during their Global Reef Expedition (GRE), I tested this hypothesis by sampling corals from among the most seemingly pristine islands and atolls in the Pacific and Indian Oceans. Although we certainly observed beautiful reefs with high coral cover (see image above) and diversity as well as a plethora of fish —all the visible hallmarks marine biologists look for in ‘healthy’ reefs—the corals themselves told a different story (Mayfield et al., 2017); high cellular stress levels were documented in the vast majority of the many hundreds of corals sampled across the GRE.

Despite looking healthy, the corals were struggling to survive.

These high stress levels do not, in and of themselves, imply that all such sampled corals are not long for this Earth. They do signify, however, that we likely never visited ‘pristine’ reefs during the GRE, despite studying some of the most remote coral reefs on the planet. This is a testament to the wide reach of climate change. This statement may come as a surprise to some, who, like me, assumed that somewhere out there, one might find corals entirely untouched by humankind, but this unfortunately does not appear to be the case.