There is a large aboriginal midden south of beach one on the edge of a large sand blow out. Recently a lot of the of the midden have been eroded out and formed a long scree field mainly of pipi shells below the midden. Look over the shells it was soon evident that the average size of those shells collected and eat my the aboriginals 200+ years ago is significantly bigger that even the largest shell I could find on the beach today.
I took a look at that dune with midden shells eroding out. Apart from the size differences that you point out in your blog, I also noticed how white/pale the pipi shells are compared with the present-day Pipis.
ReplyDeleteI considered whether some bleaching/leaching may have occured, but although Pipi seems to make up the bulk of the scree from the midden material there are rare mussel shells amoungst them which are as purple as modern ones.
Ive read that Pipi shells can incorporate dyes or pollutants from their enviroment, but the realisation from the visual contrast of past and present shells as to Western cultures impact on Venus Bays enviroment was sobering.