"[Observation is for larger pink/red barnacles] ""The consistent thatching on the sides of the large pink ones is pretty indicative of Tetraclita rubescens."" From @kestrel Both the small white and large red barnacles are acorn barnacles (compared to gooseneck barnacles). The red are Pink acorn barnacle (Tetraclita rubescens) and the smaller white are probably Chthamalus spp. The shield limpets are probably Lottia sp, possibily L digitalis or L austrodigitalis."