The critical swimming speed of the sand smelt (Atherina presbyter Cuvier) in relation to capture at a power station cooling water intake

Critical swimming speeds (CSS) of sand smelt, Atherina presbyter , were measured in a laboratory flume. Individuals of all age classes (0+ to III +) found in the vicinity of Fawley power station, Hampshire, were tested at temperatures covering the seasonal range. The median CSS was 2.7 body lengths per second (bl s⁻¹) at 5.8 °C, rising to 5.7 bl s⁻¹ at 18.5°C.
A two-variable (water temperature and body length) regression model was fitted to the data, and this was used to assess escape potential of fish coming into contact with the power station cooling water intake currents and the extent of possible bias in fish length data collected from this source. It is concluded that the sand smelt remains vulnerable to entrainment at the power station over its whole length range and over the full range of seasonal temperatures and that size-dependent swimming performance will not lead to significant bias in sample length distributions.