Just like mantas, turtles and sharks, seabirds are an integral part of a healthy atoll ecosystem. Seabirds are a remarkable group of birds who forage hundreds of kilometres offshore in the open ocean and find important nesting habitat on remote islands such as in the Maldives. In fact, atolls are global hotspots for tropical seabirds, with more than 31 million bird nesting on atoll islands across the Indo-Pacific (Steibl et al. 2024) – this is more seabirds than in all of Europe combined! As a result of their highly pelagic feeding, seabirds are important connectors between island and ocean. Seabirds obtain energy and nutrients from marine sources, which are then released onto the islands as poop (or guano). This seabird guano is highly beneficial for the terrestrial and nearshore marine environment.

Studies found that coral reefs around seabird islands are healthier, with corals growing up to four times faster (Savage 2019), the reefs having up to 50% more fish (Graham et al. 2018), and the corals becoming more resilient to marine heatwaves (Benkwitt et al. 2023). The beneficial effects of seabird-nesting on atoll islands have been revealed to link all the way to reef mantas as well: a study from Palmyra Atoll in the Central Pacific demonstrated that the seabird nutrients around nesting islands stimulate plankton blooms, and as a result manta rays aggregated and fed in much larger numbers around the seabird atoll island (McCauley et al. 2012). Having seabirds nesting on atoll islands is therefore critical for a healthy ecological connection between land and sea.

In the Maldives, much focus has been placed over the past decades on preserving marine life and coral reefs. With the growing awareness on the intricate connection between land and sea, and the critical role that seabirds are playing in maintaining this ecological connection, as well as the global importance of atolls for nesting seabirds (Steibl et al. 2024), Manta Trust has recently started to support a research programme led by the University of Auckland, New Zealand, in collaboration with EPA Maldives. The goal is to identify, protect, and restore seabird nesting islands in the Maldives, and to revive the reciprocal relationship between healthy islands and healthy oceans.

In July 2023, a first scoping expedition by Prof James C. Russell and Dr Sebastian Steibl (both University of Auckland) made a promising discovery for one of the Maldives’ most iconic seabirds, the white-tailed tropicbird (or Dhandifhulhu Dhooni in Dhivehi). The researchers visited Kurehdhoo island in Lhaviyani Atoll and realised that a large nesting colony of this seabird had established on this resort island. After two complete island surveys in July 2023 and January 2024, the researchers concluded that about 800 white-tailed tropicbirds are using this resort island as their year-round nesting ground (Russell, Steibl & Stevens 2024). This makes Kurehdhoo island the largest known nesting colony for white-tailed tropicbird in the Central Indian Ocean!

This internationally significant seabird colony did not establish on Kurehdhoo by accident. Tropicbirds, like most seabirds, are highly vulnerable to invasive predators, such as rats. On islands where rats have been introduced, seabird colonies rapidly decline or can become extirpated altogether. The resort on Kurehdhoo, however, runs an effective pest control on the island for over 15 years, and has therefore essentially created an invasive predator-free safe haven for seabirds. The researchers take this finding of the tropicbird colony on Kurehdhoo as a promising sign for the beginning of their year-long endeavour with EPA Maldives to bring back seabirds to many islands across the Maldives. “Seabirds are still present in the Maldives, and clearly respond very positively to the removal of invasive predators” says Dr Steibl. Over the next years, the researchers and EPA Maldives will establish more predator-free sanctuary islands for seabirds, with the goal to revive the intricate connection between land and sea in the Maldives.

References:

Savage 2019: https://doi.org/10.1038/s41598-019-41030-6

Graham et al. 2018: https://doi.org/10.1038/s41586-018-0202-3

Benkwitt et al. 2023: https://doi.org/10.1126/sciadv.adj0390

McCauley et al. 2012: https://doi.org/10.1038/srep00409

Steibl et al. 2024: https://doi.org/10.1038/s41559-024-02496-4

Russell, Steibl & Stevens 2024: http://www.marineornithology.org/article?rn=1581

NOTES TO EDITORS:

• The Manta Trust is a UK-registered manta ray conservation charity, co-ordinating global research and conservation efforts around manta rays: www.mantatrust.org

• For Press Enquiries please contact: Jasmine Corbett, Manta Trust (jasmine.corbett@mantatrust.org)