Photo credit: Paul Horn/Inside Climate News
Photo credit: Paul Horn/Inside Climate News
The new study measures the “reef accretion potential” for the islands and shows that it is twice as high on lagoon and marine reefs around rat-free islands with numerous seabirds than around rat-infested islands. That would be “enough to exactly keep pace with projected sea level rise by the end of the century under a 2° Celsius warming scenario,” said co-author Casey Benkwitt, a California-based restoration scientist at The Nature Conservancy.
Without seabird populations, reef growth rates are less likely to keep pace with projected sea level rise, she added.
Graham cautioned that the study does not imply a magic solution to the effects of global warming on low-lying islands. No direct comparisons were made before and after restoration, and the data came from islands with varying levels of seabird and rat infestation, differences that the research team attempted to reconcile using an ecosystem energetics framework.
And reef accumulations don’t always mean an atoll is growing vertically, because global warming is also changing waves, winds and currents that affect where the material ends up. The study also focused on largely uninhabited or sparsely populated islands with space for native ecosystems. On developed atolls, he said, restoration efforts can be helpful but do not replace the need for technical solutions.
The study helps reveal a nearly complete cycle, “from seabirds foraging in the ocean, through native forests and coral reefs, to the construction and stabilization of the islands on which the birds breed,” ecologist Hillary Young wrote in a Science Advances Focus commentary. Quantifying the cycle provides “much-needed evidence that the fate of an atoll cannot be understood or managed by treating land and sea separately,” she wrote.
Local conservation can influence physical resilience to rising sea levels, but, she wrote, “rapid reductions in greenhouse gas emissions remain essential for the long-term viability of these systems.”
Bob Berwyn is an Austria-based reporter who has been covering climate science and international climate policy for more than a decade. He previously covered the environment, endangered species and public lands for several Colorado newspapers and also worked as an editor and editorial assistant at community newspapers in the Colorado Rockies.
This story originally appeared on Inside Climate News.
