These whelks were likely harvested by bottom-fishing. The size distribution was similar to that for modern southern English whelks. The very consistent size-shape relationships suggest they were all dredged from a similar habitat, probably in fast tidal flows. Their damage pattern is characteristic of trawling, and some were trawled repeatedly. It is also likely these whelks were dredged from a bed of oysters. The whelks were infested in a similar manner as many of the oysters in the same deposit, and the infestation included oyster spat, which tend to prefer other oysters.
This would appear to be the first archaeological instance of bottom-fishing for whelks being diagnosed via shell damage, and the first archaeological evidence for whelk harvesting being incidental to oystering. Direct evidence for bottom-fishing might be present in other archaeological shell-fish. Direct evidence was found in medieval oyster shells for harvesting with tongs (Dupont 2010). Damage as a result of trawling could not be differentiated from that due to natural causes in dog-cockles (Ramsay et al. 2001) or scallops (Schejter and Bremec 2007), but might be distinguishable in razor-clams (Gaspar et al. 1994). Bottom-fishing damaged carpet shells (venerids) but had little effect on Spisula, Donax or Mactra (Gaspar et al. 2002).