During the week of highest cell density, mussels of different size
classes exhibited different levels of toxicity as shown in Fig. 3. The
different classes are based on the mussel shell lengths collected,
with 5.0 mm range per group, and expressed as mean mussel shell
lengths. There are only five size classes assessed to establish this
trend because of the short period wherein Pbc cell density is high.
Nonetheless, it was observed that mussel toxicity increases linearly
with mussel shell length with the larger mussels 25 times more toxic than the mussels a centimeter shorter. In terms of age, this
translates to an increase of 40 units in mussel toxicity for a yearolder
mussel.