14 Amphibalanus improvisus

14 Amphibalanus improvisus

A. improvisus is dominant, though unobtrusive below adhering sediment, on these stones in the tidal River Dee, Flintshire, Wales. Measured salinity 0.0 ‰, but absence of freshwater mollusca suggests saline influxes at high water. Austrominius modestus is the dominant barnacle 2.5 km downstream (0.5 ‰ recorded).