ATTACHMENT STRENGTH OF ZEBRA MUSSELS ON NATURAL, POLYMERIC, AND METALLIC MATERIALS

Zebra mussel (Dreissena polymorpha and D. bugensis) fouling has increa sed operating and maintenance costs for marine and industrial faciliti es. An understanding of zebra mussel attachment strength on various su bstrates of different surface roughness is useful for the development of control strategies. Mussel attachment strength was inferred directl y through tensile loading experiments using a calibrated force scale, and indirectly through fluid detachment using a wall jet. The results of both techniques were consistent and yielded statistically significa nt differences for different substrate types (natural greater than or equal to metallic > polymeric). Attachment varied significantly with m aterial (P < 0.01) and with surface roughness within a material (P < 0 .05). The lowest attachment strengths were measured on (in increasing order of attachment strength) smooth polytetrafluoroethylene, polymeth ylmethacrylate, and aluminum. The strongest attachment was measured on rough limestone/dolomite cobble, and mild steel of all roughnesses. Z ebra mussel attachment strength was intermediate on, marine concrete, marine plywood, polyvinylchloride, stainless steel, and coal tar epoxy coated mild steel. These results provide preliminary design guideline s for the control of zebra mussels.