posted on 2022-04-18, 14:09authored byQuentin Mauvisseau, Lynsey R. Harper, Michael Sander, Robert H. Hanner, Hannah Kleyer, Kristy Deiner
Increased use of
environmental DNA (eDNA) analysis for indirect
species detection has spurred the need to understand eDNA persistence
in the environment. Understanding the persistence of eDNA is complex
because it exists in a mixture of different states (e.g., dissolved,
particle adsorbed, intracellular, and intraorganellar), and each state
is expected to have a specific decay rate that depends on environmental
parameters. Thus, improving knowledge about eDNA conversion rates
between states and the reactions that degrade eDNA in different states
is needed. Here, we focus on eukaryotic extraorganismal eDNA, outline
how water chemistry and suspended mineral particles likely affect
conversion among each eDNA state, and indicate how environmental parameters
affect persistence of states in the water column. On the basis of
deducing these controlling parameters, we synthesized the eDNA literature
to assess whether we could already derive a general understanding
of eDNA states persisting in the environment. However, we found that
these parameters are often not being measured or reported when measured,
and in many cases very few experimental data exist from which to draw
conclusions. Therefore, further study of how environmental parameters
affect eDNA state conversion and eDNA decay in aquatic environments
is needed. We recommend analytic controls that can be used during
the processing of water to assess potential losses of different eDNA
states if all were present in a water sample, and we outline future
experimental work that would help determine the dominant eDNA states
in water.