The estuary is one of the largest in eastern Scotland and is up to 2.5km wide.
It is on links land near the towns of central eastern Scotland that golf has been played since the 1400s.
There are warnings for further heavy snow in eastern Scotland and north east England.
It is also found locally in eastern Scotland and south Wales.
Much smaller numbers of males also use estuaries in eastern Scotland as a moulting area.
Much of eastern Scotland receives less than 870mm annually in comparison.
There were popular courts, the comhdhail, indicated by dozens of place names throughout eastern Scotland.
The first cases of grass sickness were recorded in eastern Scotland in 1907.
The site opposite, now modern flats over shops, held the main salt warehouse, serving most of eastern Scotland into the 19th century.
A rain shadow is created, bringing drier weather to much of eastern Scotland.