Using Sonic Telemetry to Track Walleye Movement within Onondaga Lake in Syracuse, NY During Biweekly 24 Hour Surveys

            Onondaga Lake, Syracuse, NY was once one of the most polluted lakes in the world because of industrial and municipal wastes.   Nutrient levels in the open water are now near mesotrophic levels; aquatic macrophytes have rebounded, and can now be found at depths of 4 meters.  Since 2000, SUNY ESF has captured 35-40 species of fish per year, but the community has shifted from being dominated by planktivorous fish to large populations of centrarchids and walleye.  The walleye in Onondaga Lake have no fishing pressure because of a New York State health advisory recommending the consumption of no walleye (elevated mercury levels).  The lack of fishing pressure has almost certainly contributed to the large number and size of walleye within Onondaga Lake.  Since 2008, walleye have been the most dominant species in our gill nets.  In 2008 CPUE (walleye/hr) was 2.0, in 2009 CPUE was 3.3, and in 2010 the CPUE was 3.5.   In 2008 the average length of captured walleye was 564 mm, in 2009 (562 mm), and in 2010 (548 mm).  The largest walleye captured by ESF sampling since 2008 was 733 mm.

            In 2010 SUNY ESF implemented a tagging program in cooperation with Honeywell and Anchor QEA to track the movements of walleye within Onondaga Lake.  The tracking study was designed to identify habitat use of walleye from June – October in 2010.  Thirteen walleye were implanted with sonic telemetry tags on May 24^th, 3 more on July 19^th, and one on October 14^th.  Two walleye were tracked biweekly; the fish’s location and temperature was recorded hourly over a 24 hr period. 

            The average distance traveled by walleye during 24 hrs was 6018 m, and ranged between 4519 m and 8196 m.  From June 4^th – August 10^th the walleye were found at depths of 4-6 m, from August 24^th through October 4^th they were found at depths of 9-13 m.  The average dissolved oxygen of the water in which the fish were found tended to decrease from June 3^rd (12.5 mg/L) to October 4th (1.0 mg/L).  The fish were found at the highest temperatures (~24 °C) from July 13 – August 10^th.  From June 3^rd to July 1^st they were found at temperatures of 19°C to 21 °C, and after August 10^th the average water temperature utilized decreased from 19 °C to 15 °C.