Use of an in-Stream Fish Counter to Measure Absolute Abundance and Identify Parameters Influencing Migration Patterns of River Herring in Black Creek, a Small Tributary of the Hudson River

In 2013, we conducted a pilot study using an in-stream fish counter in Black Creek, (located just south of Kingston NY), a small tributary of the Hudson River with a known river herring spawning run. The primary objective was to determine if a fish counting device was an appropriate method to collect absolute abundance data for river herring in small tributaries. Our secondary objectives were to identify when river herring migrate into tributaries and to identify parameters that may influence those migrations (i.e. moon phase, water level, water temperatures).  We recorded 205,426 counts during the study.  The primary peak in 2013 occurred on April 29^th and a secondary peak beginning on May 16^th. The peaks in migration into Black Creek appear to be highly correlated to a combination of moon luminosity and water temperature. Generally, river herring begin entering tributaries when water temperatures reach approximately 10.5C and spawning is reported to occur between 12-16C (Pardue 1983). We saw the same temporal influenced patterns in Black Creek in 2013.  The peak spawning event occurred at or near the peak moon luminosity, primarily at night and when water temperatures reached approximately 14C.