Complex interactions between environmental DNA (eDNA) state and water
chemistries on eDNA persistence suggested by meta-analyses
Abstract
Understanding the processes of environmental DNA (eDNA) persistence and
degradation is essential to determine the spatiotemporal scale of eDNA
signals and accurately estimate species distribution. The effects of
environmental factors on eDNA persistence have previously been examined;
however, the influence of the physiochemical and molecular states of
eDNA on its persistence is not completely understood. Here, we performed
meta-analyses including 26 previously published papers on the estimation
of first-order eDNA decay rate constants, and assessed the effects of
filter pore size, DNA fragment size, target gene, and environmental
conditions on eDNA decay rates. Almost all supported models included the
interactions between the filter pore size and water temperature, between
the target gene and water temperature, and between the target gene and
water source, implying the influence of complex interactions between the
eDNA state and environmental conditions on eDNA persistence. These
findings were generally consistent with the results of a re-analysis of
a previous tank experiment which measured the time-series changes in
marine fish eDNA concentrations in multiple size fractions after fish
removal. Our results suggest that the mechanism of eDNA persistence and
degradation cannot be fully understood without knowing not only
environmental factors but also cellular and molecular states of eDNA in
water. Further verification of the relationship between eDNA state and
persistence is required by obtaining more information on eDNA
persistence in various experimental and environmental conditions, which
will enhance our knowledge on eDNA persistence and support our findings.