Differential Cohort Mortality in Hudson Estuary Ichthyoplankton

The long-term monitoring program in the Hudson Estuary has permitted the identification of normal patterns of spawning, life stage succession, and distribution for planktonic stages of resident and anadromous fishes.  Due to the length of the data set (1974-2014) we can also identify years with abnormal patterns in these processes, resulting from high flow events, rapid ambient temperature changes, or both, during the spawning season.  These events often result in rapid advection downstream and nearly complete loss of eggs and larvae spawned in earlier weeks.  Subsequent additional spawning after these flow/temperature events is the source of the surviving year classes.  The consequences of these events are not accounted for in typical measures of entrainment effects which assume constant stage survival rates.