Mass mortalities of adult salmon, Salmo salar, in the R. Wye, 1976.
Abstract
As a result of sunny and low flow conditions during late June 1976, water temp. increased to a max. of 27.6 deg C and accelerated the decay of substantial plant stands, the growth of which had been enhanced by favorable weather: this resulted in severe deoxygenation of the water. The mass mortalities are attributed to these low oxygen concentrations in the water. From authors' summary.