Data from: Reconstructing hyperdiverse food webs: gut content metabarcoding as a tool to disentangle trophic interactions on coral reefs

1. Anthropogenic stressors have strong impacts on ecosystems. To
understand their influence, detailed knowledge about trophic relationships
among species is critical. However, this requires both exceptional
resolution in dietary assessments and sampling breadth within communities,
especially for highly-diverse, tropical ecosystems. 2. We used gut content
metabarcoding across a broad range of coral reef fishes (8 families, 22
species) in Mo’orea, French Polynesia to test whether this technique has
the potential to capture the structure of a hyperdiverse marine food web.
Moreover, we explored whether taxonomic groups (families) and traditional,
broad-scale trophic assignments explained fish diet across four different
metrics of quantifying predator-prey interactions. 3. Metabarcoding
yielded a large number (4,341) of unique operational taxonomic units (i.e.
prey) with high-resolution taxonomic assignments (i.e. often to the level
of genus or species). We demonstrate that across multiple metrics,
taxonomic group at the family level is a consistently better, albeit still
weak, predictor of empirical trophic relationships than frequently-used,
broad-scale functional assignments. Our method also reveals a complex
trophic network with fine-scale partitioning among species, further
emphasizing the importance of examining fish diets beyond broad trophic
categories. 4. We demonstrate the capacity of metabarcoding to reconstruct
diverse and complex food webs with exceptional resolution, a significant
advancement from traditional food web reconstruction. Further, this method
allows us to pinpoint the trophic niche of species with niche-based
modelling, even across hyperdiverse species assemblages such as coral
reefs. In conjunction with complementary techniques such as stable isotope
analysis, applying metabarcoding to whole communities will provide
unparalleled information about energy and nutrient fluxes and inform their
susceptibility to disturbances even in the world’s most diverse
ecosystems.