) Reveals Seasonal Movements and Diel Behavior in an Estuarine System, Long Island, NY

Acoustic telemetry was used to investigate movement and behavior of the semi-anadromous white perch (Morone americana) in the Great South Bay system. Fifteen Vemco© VR2W acoustic receivers were deployed in the Carmans River and another fifteen were placed in tributaries throughout the Bay.  Forty fish were tagged with Vemco© V9 acoustic transmitters from August 2010 – August 2011, fifteen of which returned 28+ days of movement data. Spatial use of the River varied seasonally with an expanded range during autumn and spring and contracted range during summer and winter. There were also variations in migratory behavior in the tagged perch; both residential and dispersive individuals existed within the group, suggesting connectivity between rivers. Acoustic tracking also revealed individuals exhibiting diel behavior, which was significantly reduced in autumn and winter. Summer months contained the highest percentage of ‘diel movement days’. Directionality in diel movement was also seasonal, where nightly upriver movements were favored in summer and autumn months and nightly downriver preferred in winter. Variations in spatial movement can be attributed to temperature and daylight changes. Food availability, predation, intra-specific competition, and energy conservation are also suggested to influence perch spatial behavior.