(a) Proportion of a site's L. littorea population greater than 2.06 cm in length (age class 3) as a function of site density. Data are pooled for all transects at a site, so surveys in different years are included. The curve represents the predictions of the size-structured model for L. littorea. (b) Relationship between the proportion of L. littorea >2.06 cm in length and the accessibility of shores to potential harvesters (as access minutes, Tab. 1). Sites where the access is across private land are indicated with “P”.