For Whom the Prop Tolls; Atlantic Sturgeon and Vessel Traffic in the Delaware River, USA

Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus) declined in the late 1800s due to overfishing and habitat degradation.  Despite recovery efforts, Atlantic Sturgeon were listed as endangered under the ESA in 2012.  In the final ruling determination, NOAA-NMFS listed vessel strikes, which increase during the period of likely spawning, as a threat to Atlantic Sturgeon in the Delaware River.  We monitored a 5.2km reach of probable spawning habitat near Chester, PA from mid-April to July, 2013 with a two dimensional acoustic positioning system that provided location estimates of telemetered Atlantic Sturgeon.  Shipping activity was assessed through the global Automatic Identification System, providing vessel type, position, course and speed.  Throughout our study, five telemetered adult Atlantic Sturgeon were positioned 11,468 times for an average of 4.7 days (range 3-7) within the study area.  During periods of Atlantic Sturgeon occupancy we identified 102 vessels.  We queried both datasets by time and have identified likely interaction zones. The shipping industry plays an important role in region’s economic well-being, through our efforts we hope to provide managers information that can minimize the risks associated with sturgeon/vessel interactions, balancing economic growth and recover of this imperiled species.