DNA metabarcoding analysis discloses important roles and links in the
seabird's trophic network of the Eastern Tropical Atlantic
Abstract
Predator-prey interactions provide key information on the role of each
species in the community and an overall assessment of the stability of
food webs. DNA metabarcoding has the potential to provide highly
informative data which substantially enhance trophic interactions
analysis, by providing higher taxonomic detail compared to earlier
methods. Here we show, using the Cabo Verde seabird community, that the
integrated analysis of trophic networks based on DNA metabarcoding of
faecal samples can increase considerably our understanding of the
trophic interactions in whole communities. Results revealed that these
seabird species prey mostly on fish, with most seabirds relying heavily
on very few prey species, which are also targeted by fisheries. This
community shows high specialization and modularity levels, i.e., is
dominated by seabird species with specialized diets. Such network
structure has implications for its management and conservation because
specialist predators are especially vulnerable to prey depletion. The
Cape Verde shearwater (Calonectris edwardsii), identified as the
main network connector species, was confirmed to be a suitable sentinel
species of changes in this marine food web. Our results clearly show
that network analysis can be used effectively to maximize the potential
of DNA metabarcoding in studying trophic interactions of complex
communities.