3.1 Size

Are these whelks of a size likely to have been consumed? Usually a whelk's size is measured by its shell height (e.g. Hancock 1967, 3). The smaller of these whelks were not more fragmented than the larger: the 16 more broken shells were not statistically different from the 32 intact shells in average shell height (Mann-Whitney U[31,15]: 208.5; P(same medians): 0.30) or shell height distribution (Kolmogorov-Smirnov test: D[32,16]: 0.281; P(same distributions): 0.31). Therefore the dimensions of the intact shells were a reliable sample of all the whelks.

Figure 5
Figure 5: Distribution of shell height in the whelks from midden 7325 (N: 48).

The intact and more-broken whelks combined had shell heights that ranged from 37.7–79.0mm and averaged 51.4 ± 9.1mm. The distribution of heights (Figure 5) was highly positively skewed (skewness statistic was 1.41, and 15% were over 60mm high). Whelks less than 40mm were really not acceptable for harvest (only one was less than 40mm); this is not very different from the modern European legal landing size of 45mm (EU 1998, 29). The sizes were similar to modern southern English whelks: those potted recently off Deal in Kent ranged from 31–89mm, averaging 54.3mm (Shelmerdine et al. 2006, 2).