Data from: Interspecific allometric scaling in eDNA production among Northwestern Atlantic bony fishes reflects physiological allometric scaling

Relating environmental DNA (eDNA) signal strength to organism abundance
requires a fundamental understanding of eDNA production. A number of
studies have demonstrated that eDNA production may scale allometrically –
that is, larger organisms tend to exhibit lower mass-specific eDNA
production rates, likely due to allometric scaling in key processes
related to eDNA production (e.g. surface area, excretion/egestion). While
most previous studies have examined intra-specific allometry,
physiological rates and organism surface area also scale allometrically
across species. We therefore hypothesize that eDNA production will
similarly exhibit inter-specific allometric scaling. To evaluate this
hypothesis, we reanalyzed previously published eDNA data from Stoeckle et
al. (2021) which compared metabarcoding read count to organism count and
biomass data obtained from trawl surveys off the New Jersey coast. Using a
Bayesian model we empirically estimated the value of the allometric
scaling coefficient (‘b’) for Northwestern Atlantic bony fishes to be 0.77
(credible interval = 0.64 – 0.92), although our model failed to converge
for Chondrichthyan species. We found that integrating allometry
significantly improved correlations between organism abundance and
metabarcoding read count relative to traditional metrics of abundance
(density and biomass) for bony fishes. Although substantial unexplained
variation remains in the relationship between read count and organism
abundance, our study provides evidence that eDNA production may scale
allometrically across species in some contexts. Future studies
investigating the relationship between eDNA signal strength and metrics of
fish abundance could potentially be improved by accounting for allometry;
to this end, we developed an online tool that can facilitate the
integration of allometry in eDNA/abundance relationships.