2015-2016 Acoustic Telemetry data for European eels (Anguilla anguilla) in Hanningfield reservoir, Essex, UK

Data from the tagging and tracking of European eels (*Anguilla anguilla*) in Hanningfield reservoir in 2015 and 2016. Acoustic tagging was undertaken on 36 eels between September and December 2015, then again on 68 eels between June and August 2016. In each year, the fine-scale movements of eels in the reservoir were tracked for a 6-month period. Various biometric recordings were taken whilst the eels were anaesthetised, such as total length and weight, pectoral fin size and length, vertical and horizonal eye measures, and lipid percentage.