Seabird guano and native trees keep islands above rising seas: Study

Low-lying tropical atoll islands appear remarkably vulnerable to climate change. But when shrouded with native forests and with abundant seabird populations, these islands may keep up with rising sea levels, a new study finds. Seabirds act as biological pumps, moving nutrients from feeding areas in the open ocean to roosting and nesting areas on land and, eventually, back into the ocean. The recent Science Advances study traces how energy from nutrient-dense seabird guano trickles through terrestrial and marine ecosystems on atoll islands. The findings show that these nutrients, along with native vegetation, boost processes that build and maintain the island’s reef and underlying structure, even in the face of rising seas. Rewilding atoll islands — many of which no longer support seabirds and have seen native forests replaced by coconut palms — builds climate resilience, as well as benefiting biodiversity, Nicholas Graham, distinguished professor at Lancaster University, England, and the study’s first author, told Mongabay in a video call. “It’s really telling us something about the islands themselves,” Graham said. “Seabirds and native vegetation actually support the resilience of the islands themselves to sea level rise, which I think is fascinating and really quite positive.” Atoll islands of Tetiaroa Atoll, French Polynesia. Seabirds and native vegetation make low-lying atoll islands more resilient to sea level rise due to climate change, according to a recent study. Image by Yadvinder Malhi. Graham and colleagues first began looking into the connection between seabirds, islands and reefs nearly a decade ago. At the time,…This article was originally published on Mongabay