Lake Sturgeon Summer Habitat Use in the Erie Canal System

Lake sturgeon is currently listed as a threatened species in New York State.  Since 1994, the DEC has periodically stocked lake sturgeon in the Oswego River (Erie Canal) system, with releases in Oneida and Cayuga lakes.  Relatively little is known about 1) habitat quality for lake sturgeon or 2) their habitat use within the canal in central New York.  We evaluated habitat quality for foraging lake sturgeon by applying the existing habitat suitability index (HSI) during the summers in 2009 and 2010.  Habitat variables of importance in the HSI are water depth, current velocity, and substrate particle size.  We also captured lake sturgeon throughout the canal system using 24-hr gill net sets to test consistency of use with the HSI.  Based on the HSI, every site had a lower adult index score, which is determined solely by substrate size.  We have not found strong relationships between any of our habitat variables and use by sturgeon.  All lake sturgeon were caught at sites with depths between 4-7m and current velocities less than .15m/s.  Future analyses will examine more subtle habitat use patterns associated with interactions among variables.  Proximity to lakes and barriers may also be important factors influencing lake sturgeon distribution during the summer months.  Preliminary analyses suggest that use of the lake sturgeon HSI, as it was developed, may not be appropriate for the Erie Canal system.