Photo credit: phys.org
Seabirds and Atolls: A Vital Connection
A collaborative effort by marine and avian biologists from institutions including the University of Auckland, the Karolinska Institute, the Nature Conservancy, and the University of California has led to a comprehensive survey that sheds light on seabird nesting patterns on Indo-Pacific atolls.
The findings of their research appear in a recent article published in Nature Ecology and Evolution. In the same issue, Ruth Dunn of Heriot-Watt University contributes a News & Views piece that highlights the significance of the team’s work.
Atolls, unique ring-shaped coral reef islands, originate from volcanic activity and are formed when the volcano sinks below sea level, leaving the surrounding coral structure intact. Previous studies have indicated that atolls serve as crucial habitats for seabirds, offering a relatively safe environment for foraging and nesting.
Moreover, seabirds play a reciprocal role in this ecosystem; their guano enriches the soil and facilitates the dispersal of various plant seeds. However, research on the specific numbers of seabirds nesting on these atolls had been scarce. This recent study sought to fill that gap by conducting an extensive survey in the Indo-Pacific region.
The research team aggregated data from over 90 datasets, encompassing millions of seabird records, including nesting locations across 199 out of the 280 atolls in the region. Their results revealed that approximately 25% of tropical seabird species utilize atolls for nesting, with more than half of the 14 species studied identified as regular nesters on these islands.
Additionally, they documented that atolls serve as breeding grounds for 37 different seabird species, with populations on individual atolls varying dramatically—from a few dozen to over 3 million birds. The broader estimate suggests that more than 31 million seabirds find nesting sites on these atolls.
Beyond nesting, seabirds also forage in areas spanning between 10,000 and 100,000 km² around the atolls and contribute significantly to the ecosystem by depositing between 65,000 kg of nitrogen and 11,000 kg of phosphorus annually per atoll. These findings underscore the ecological importance of atolls for seabirds, revealing their role to be even greater than previously understood.
Further Reading:
Sebastian Steibl et al, “Atolls are globally important sites for tropical seabirds,” Nature Ecology & Evolution (2024). DOI: 10.1038/s41559-024-02496-4
Ruth E. Dunn, “Atolls are vital for seabirds and vice versa,” Nature Ecology & Evolution (2024). DOI: 10.1038/s41559-024-02518-1
Source
phys.org