How have migratory fish returns to the Piscataqua Region changed over time?
Overall migratory river herring returns to the Great Bay Estuary increased 69% between 2012 and 2016, however river herring returns have sharply declined for the Oyster and Taylor Rivers. Returns for American shad have been consistently fewer than five since 2011 and zero were reported in 2016. There are no statistically significant trends. A lack of fishable ice resulted in insufficient data for Rainbow Smelt in 2012, 2013, and 2016.
Despite increases in river herring returns for some rivers, the Oyster and Taylor River populations have declined dramatically in recent years most likely due to poor water quality in impoundments upstream.56 Additionally the Winnicut River fish ladder has been declared ineffective and NH Fish and Game is working on a solution.57 The 2016 river herring returns are almost exclusively from the Lamprey and Cocheco Rivers.