Advancing Seabird Diet Studies Through Buccal Swabbing for DNA Metabarcoding

Area of Science:

• Marine Ecology
• Avian Biology
• Conservation Science

Background:

• Seabirds act as indicators of ocean health, necessitating accurate dietary studies for ecological understanding and conservation.
• Traditional methods for determining pelagic seabird diets face limitations, especially for wide-ranging species.
• Understanding seabird diets is vital for monitoring marine trophic webs and detecting ecosystem changes.

Purpose of the Study:

• To evaluate buccal swabbing and DNA metabarcoding as a combined, minimally invasive method for seabird diet analysis.
• To determine the diet of Manx shearwaters (Puffinus puffinus) and northern fulmars (Fulmarus glacialis) during the breeding season.
• To assess the utility of this method for informing conservation and detecting ecosystem shifts.

Main Methods:

• Investigated buccal swabbing coupled with DNA metabarcoding.
• Sampled Manx shearwaters and northern fulmars at different breeding stages.
• Analyzed amplified prey DNA to identify fish taxa in collected samples.

Main Results:

• Detected 14 fish taxa; prey DNA amplified in 68% of Manx shearwater and 28% of northern fulmar samples.
• Provided first species-level dietary data for chick-provisioning Manx shearwaters, indicating reliance on European sprat (Sprattus sprattus).
• Identified new prey taxa for northern fulmars, including fishery discard species, highlighting their dietary importance.

Conclusions:

• Buccal swabbing and DNA metabarcoding is a viable, minimally invasive tool for pelagic seabird dietary analysis.
• Manx shearwaters and northern fulmars may be sensitive to changes in prey availability and fishing activities.
• Dietary data supports informed conservation strategies for these seabird populations and marine ecosystems.