Absence of anadromous fish spawning activity after Embry Dam removal on the Rappahannock River - Slow restoration?

Embrey was breached in February 2004 and entirely removed in March of 2005.  Springtime sampling in 2005 and 2007 was conducted to determine if Alsoids were using upstream habitats for spawning.   The study was conducted as part of the Rocky Pen Reservoir assessment as the intake site is located within the bounds of newly opened waters in the upper Rappahannock River.  Ichthyoplankton densities in the immediate vicinity of the intake were determined using towed and fixed bottom plankton nets. Alosid eggs and larvae were found up stream of the breached dam in both survey years.  However, the number of eggs and larvae were extremely low compared to established spawning grounds.  In 2007 an ichthyoplankton survey conducted below the old site of Embry day in the tidal Rappahannock produced hundreds of eggs and larvae in single 5-minute tows.  At the upstream intake site we captured less than 200 specimens in 90 collections taken in 15 separate sampling events in both the 2005 and 2007 spring spawning season.  The data suggest recovery to pre-dam conditions is not immediate potentially taking years to decades to be fully utilized by spawning Alosids.