Survey of the Inner Firth of Forth using grab samples. Carried out as part of an MSC thesis, with a view to re-introducing oysters to the Firth. The times at which samples were taken was not recorded during sampling. Thus, approximate times have been allocated to each site using regular time intervals. The tidal corrections, calculated from the time of sampling, are, therefore, also approximate. Further, it appears from plotting the site locations that samples were taken in the order of Site Number, rather than Field Number ie the field and site numbers have been entered in the wrong boxes. This has been corrected on survey and site forms and on the database, and the switch indicated on the habitat forms.