Collaborative 316b Study of Seven Power Plants on the Ohio River, Year 1 Results

In 2015, a 2-year collaborative study of seven power plants on the Ohio River to meet the requirement of 316b Rule regarding an “Entrainment Characterization Study”.  Because of the collaborative nature of the study, the study plan was standardize and the collection methods for all plants. 

Almost no larvae were collected March, September, or October.  Peak larval abundance at all plants was from late May through mid-June. In Year 1, we estimated that entrainment at the plants ranged from about two hundred million eggs and larvae to over a billion eggs and larvae, depending on plant.  Although these numbers are fairly high, we determined that the vast majority of the eggs and larvae entrained were rough or forage fish (e.g., Emerald Shiner, Freshwater Drum, and Ictiobinae).  Thus, the value associated with entrainment at each plant will likely be fairly low.  Based on the temporal pattern of larval abundance, we have adjusted the sampling period for 2016.  In 2016, we will begin sampling in mid-April and finish at the end of August and will sample more frequently during the expected larval peak.  This will reduce the variance associated with the density estimates, leading to more accurate and precise entrainment estimates in 2016.