Butter clams from 11,500-11,000 years ago (left) and 10,900-9,500 years ago (right) showing the sometimes dramatic differences in size through time. Disclaimer: AAAS and EurekAlert! are not ...

The 70 clams collected, which were of varying sizes, yielded a median level of saxitoxins of 83 micrograms per gram, just above the 80-microgram limit. Toxin concentrations differed from clam to ...