LAUSR

We conducted a preliminary passive acoustic survey of the occurrence of freshwater drum in the New York State Canal System (NYSCS). Similar to more well studied marine members of the Sciaenidae, freshwater drum calls are composed of highly variable trains of 1 to 119 knocks/call (mean = 25 knocks/call), a mean knock period of 33 knocks/s, mean peak frequency of 400 Hz, and mean duration of 0.8 s. The occurrence of reproductively active freshwater drum, as evidenced by the presence of chorus calling throughout the canals, suggests that native drum populations from Lake Champlain, Lake Erie, and Lake Ontario likely all contribute to the Hudson River invasive population. We suggest that freshwater drum most likely also invaded the finger lakes through the NYSCS. The invasion of the Hudson River by freshwater drum is significant because the species had previously been geographically excluded from the entire east coast. It is a prolific species with the widest distribution of any native species in the Americas...