Search

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 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. [ABSTRACT FROM AUTHOR]

Reliable, timely and economical target organism detection in harbors and ballast water is urgently needed to prevent spread of aquatic invasive species (AIS) by commercial ships in the Great Lakes (GL). Laker ships transport large volumes (ca. 52 million metric tons) of untreated lake water from the lower lakes to Western Lake Superior and constitute the primary vector of AIS spread throughout the GL. eDNA detection and identification of target organisms could enhance control of ballast-mediated AIS spread through rapid detection. To that end, we developed species-specific reliable eDNA probes and qPCR protocols to detect four target AIS in whole water samples. Criteria for AIS selection were as follows: 1) they are known to be invasive in the lower GL; 2) they are established in the lower GL but not in Superior; 3) they are capable of being entrained and transported in ballast water; and 4) specimens are readily obtained, morphologically distinct and have existing DNA sequence information available. Following our criteria, we created and tested working eDNA probes for: Daphnia lumholt%i (a spiny waterflea), Cercopagis pengoi (the fishhook waterflea), Nitellopsis obtuse (Starry Stonewart), and Echinogammarus ischnus (a scud). [ABSTRACT FROM AUTHOR]