Fish Community Changes in Schoharie Creek Tributaries (Mohawk Valley, NY) Following Hurricane Irene and Tropical Storm Lee

Hurricane Irene and Tropical Storm Lee delivered an unprecedented 500 year flood event to the Schoharie Creek watershed on 26 August and 6 September 2011.  Eight streams in the watershed historically supporting wild brook trout were surveyed, once before and twice after flooding.  Flooding and ensuing mitigation (reduced sinuosity, berms, channelization and riparian damage) dominated 75% of survey sites (12/16).  Average turbidity increased drastically (196%) from pre-flood to 2013 post-flood, most notably in downstream reaches.  The turbidity increase was likely due to a lack of riparian buffers from post-flood stream bank modifications such as channelization.  Brook trout (Salvelinus fontinalis) CPUE was higher in both post flood surveys, potentially due to reduced habitat complexity, resulting in greater capture efficiency.  Brown trout CPUE returned to pre-flood levels 18 months post-flood.  Slimy sculpin (Cottus cognatus), a sensitive riffle species, showed marked CPUE declines, despite increased riffle habitat.  Conversely, blacknose dace (Rhynichthys atratulus), a tolerant riffle species, showed a sharp CPUE increase.  Post-flood downstream sites had altered, unsuitable habitat with poor water quality, negatively impacting trout abundance.  Bearkill Creek (not drastically impacted by flooding), maintained habitat diversity, resulting in increased fish abundance across all species.