Pre Fishery Population Assessment

EDF Abundance Data – Estimation of a single tidal population in the Severn estuary.

There is no doubt that estimating tidal populations in wide estuaries is challenging and requires significant resources. Though a survey for EDF may not have been conclusive in terms of making comparative population studies between year 2013 and 2014 it was a comprehensive survey. Glass eel abundance data was collected at the surface, midwater and across the whole width of the channel including the Welsh and English shores. Some assumptions have to be made about the distribution of glass eels. There is however sufficient data to give an indication of estuarine mean population densities.

Velocity Experiment

Investigation of failure of glass eels to migrate through tidal defence barrier on the River Frome (SO7517410472)

Tewkesbury Weir Study

Investigation of failure of migrating juveniles to cross Tewkesbury Weir

Second Velocity Experiment

An experimental study of the swimming velocity of glass eels