Dumb me! I deleted before I got the name of the writer. But someone
wrote about introduced clams or oysters that could filter San
Francisco bay every 24 hours. How many critters would it take to do
the job? Six? Nineteen? several million?  When SF is finally cleaned
up, do they die or keep filtering? Could they do the same for
Chesapeake Bay? If it can be done, why isn't it being done?
    The Question Man