Yes I have found mussels in striper stomachs on a few occasions. The issue is that mussel shell has to be crushed so the tissue inside the shell can be digested. If the shell is still intact there will be no nutrition gained from eating mussels. Stripers also are sometimes not good at eating crayfish. They often grab at the crayfish -miss - and then eat a rock instead. I have found 13 sliver dollar size rocks in one striper stomach. Stripers need shad to be fed well. Without shad they are not obtaining the nutrition needed to remain in good health. We need to give them an introductory class in how to eat mussels and crush the shell. That would be a win-win situation for Lake Powell.