I don't know about quagga mussels, but last week I dove in a quarry where the zebra mussels easily colonized everything down to the bottom at 80 feet or so. Bei

I don't know about quagga mussels, but last week I dove in a quarry where the zebra mussels easily colonized everything down to the bottom at 80 feet or so. Being filter feeders, I can't imagine the depth bothers them much.