Organic Matter Matters to Yellow Perch Larvae in Chesapeake Bay Subestuaries: Watershed Development Impacts Early Feeding Success

We examined whether development negatively influenced watershed organic matter (OM) dynamics, altering zooplankton production important for yellow perch larval feeding success and survival (the OM hypothesis) in Chesapeake Bay subestuaries.  Urbanization may negatively impact quantity of OM by diminishing marshes and forests that provide OM and through stormwater management that disconnects transport of OM.  During 2010-2012, larval relative abundance, length, feeding success, and diet composition and relative OM levels were estimated in six subestuaries with rural to suburban watershed development.  As development increased, the presence of OM declined, as did the relative fullness of larval guts and L_p.   Estimated development level was positively correlated with absence of OM (r = 0.75, P = 0.01) and negatively correlated with mean fullness rank (r = -0.51, P = 0.04), while absence of OM was negatively correlated with mean fullness rank (r = -0.64, P = 0.05).  The type of food present in larval yellow perch guts (copepods, cladocerans, or “other”) was not significantly associated with development or OM, but mean gut fullness rank was correlated with the presence of copepods (r = 0.86, P = <0.0001).  Most watershed management and restoration practices have the potential to increase OM delivery.