Straw Protocol for Early Detection of Ballast-Mediated Target AIS in Great Lakes harbors using PCR

Abstract:

Harbor monitoring for rare species in Great Lakes harbors is expensive, demanding, and time-consuming using conventional methods. Yet early detection of newly established AIS can be the only way to prevent their further spread from the lower Great Lakes to Lake Superior in Laker ship ballast transfers, which are still untreated. Routine surveillance for target species eDNA using novel PCR tools can deliver vital information about potential reproducing target organism populations in harbors of ballast uptake. Though PCR does not discern live/dead status of organisms associated with detected eDNA, live status can be inferred from repeated eDNA positive outcomes from sampling of uptake locations over time, especially in the context of known hydrologic patterns. More expensive and time-consuming conventional sampling could then be targeted to locations with positive eDNA signals for confirmation purposes only. We developed and applied criteria to select a Great Lakes harbor and target organism, and designed a straw repeated-measures monitoring protocol adaptable to a range of hydrologic considerations.