River herring data and metadata for the Patapsco River

The purpose of the proposed project was to provide information on river herring responses to the removal of Bloede Dam in the Patapsco River, Maryland. Ichthyoplankton samples were collected in spring 2024 at sites downstream and upstream of the former Bloede Dam site to determine the extent of river herring spawning activity in the restored reach of the Patapsco River. The samples were processed under a dissecting microscope to identify and quantify river herring eggs and larvae. Data from all previous SERC studies related to river herring responses to removal of Bloede Dam were also compiled and made publicly available along with data from the 2024 ichthyoplankton collections. These prior data, collected during projects funded by the National Fish and Wildlife Foundation (NFWF) and the Smithsonian Institution, include spawning activity from ichthyoplankton collections, presence and relative abundance data from environmental DNA (eDNA) sampling, run counts from high resolution imaging sonar, species composition and relative abundance from electrofishing, age and spawning history data from otoliths and scales, and individual movements and return rates from passive integrated transponder (PIT) telemetry. Integrating across many data types provided a comprehensive picture of river herring use of the Patapsco River before and after removal of Bloede Dam in 2018/2019.