PHD Project

October 11, 2023

From wings to fins: ecological connectivity between seabirds, mangroves and coral reefs

Mangrove underwater and above water

Do seabirds enhance the connectivity of reef fishes and elasmobranchs between mangroves and coral reefs? Seabirds forage for fish in the open ocean, returning to islands to roost and breed. In doing so, they transfer nutrients to islands through their droppings (guano), which is known to boost plant and animal productivity in island ecosystems. Seabird nutrients can also enter nearshore coral reef environments, boosting fish and coral growth, and helping coral reefs respond to climate impacts. Many tropical coastlines have extensive mangrove forests adjacent to coral reefs. These habitats provide important nurseries for species of reef fish, sharks and rays, increasing their numbers on adjacent coral reefs. Seabirds also frequently use mangroves as roosting and nesting sites, yet the role that seabird-derived nutrients play in mangrove-to-coral reef connectivity is not understood. It is likely that seabird nutrients influence the use of mangrove areas by reef fish and sharks, that the fish and sharks move nutrients between habitats, and that reef habitats adjacent to mangroves with seabirds show beneficial ecological responses. This project will investigate this issue at Aldabra Atoll, a world heritage site in the southern Seychelles. Aldabra is ideally suited to the question, with the extensive lagoon fringed by >1200 ha of mangrove forest, hosting varying densities of red-footed booby and frigatebird colonies. Many small coral reef patches and islets provide experimental units at varying distance from the mangroves. The project aims to assess how reef fish and sharks use mangrove habitats of varying seabird density, quantify their spatial movements to adjacent coral reef habitats, and determine ecological responses of reef communities. Mentoring and professional development opportunities will be provided by leading researchers at Lancaster University, Bangor University, and the Seychelles Islands Foundation.

Eligibility.

Candidates shall be good honours graduates in appropriate subject areas, of a recognised university or comparable university, or persons holding equivalent qualifications who show evidence of exceptional ability, or who have demonstrated their ability in graduate studies.

Email address for enquiriesnick.graham@lancaster.ac.uk