Reproduction influences seasonal eDNA variation in a temperate marine fish community

Many factors influence how environmental DNA (eDNA) abundance varies in natural environments. One of the least studied contributors to eDNA variation is that of reproduction. Marine organisms that broadcast spawn are expected to shed increased quantities of DNA in association with the release of gametes and the elevated levels of activity associated with reproduction. To test this hypothesis at the community level, we present a year-long eDNA time-series of a temperate sea-shelf fish assemblage combined with adult fish and ichthyoplankton abundance data. Our results show that eDNA is associated with species abundance estimated by conventional fish surveys at all life stages (adult, larval, and egg), and was on average 2.3-fold more abundant during predicted fish reproductive periods.

Automated summary

Many factors influence the abundance variation of environmental DNA (eDNA) in natural environments, and one of the least studied contributors is reproduction. This study presents a year-long eDNA time-series of a temperate sea-shelf fish assemblage, and finds that eDNA is associated with species abundance at all life stages and is 2.3 times more abundant during predicted fish reproductive periods.