Smaller man-made structures are also vulnerable to zebra mussel infestation. Zebra mussels have caused increased maintenance costs for waterfront property owners, recreational boaters, and fishermen. Docks, seawalls, boats, boat lifts, and ladders all provide hard substrates for mussels to settle on in inland lakes and rivers, as well as in the Great Lakes. Owners must scrape these substrates annually to remove mussels that could otherwise impede function and damage structural integrity. This boat lift and this ladder were removed from Lake Wawasee, Indiana, in October 1992, less than a year after mussels were first reported in this lake.
Note the zebra mussels attached to the lift in the close-up.
These mussels settled out and attached to this lift in one season (June-October).
Zebra mussels may colonize fishing nets and navigational buoys where the added weight of zebra mussel colonization can render them useless by dragging them under the water. The cost of retrieving, cleaning, and deploying additional buoys and nets can be a further expense.
The trailering and passage of boats from one body of water to another has significantly contributed to the rapid spread of zebra mussels. Whether it be the recreational boater, the angler, or commercial barges, great care needs to be taken to avoid the transfer of zebra mussel "stowaways.” Zebra mussel adults can be found attached to the aquatic plants that have been snagged by props or drive units. These are easily transported from water body to water body and are naturally a moist and shaded environment for the mussel to remain alive in. The zebra mussel veliger is most often transported in live wells, in bilges, within the engine cooling systems, and in bait and collection buckets. Following preventative guidelines (see Slowing the Spread of the Zebra Mussel) will not only help to slow the spread of the zebra mussel across North America, but will also help to protect and prevent zebra mussel fouling of boating equipment, which can be extremely costly.
Colonization on engine outdrives and engine cooling water intakes can lead to engine overheating and damage to cooling system parts. Mussels in or around the shafts and propellers of recreational boats can cause drivetrain wear.
Along shorelines, windrows of mussels destroy beaches and the decaying mussels produce an extremely foul smell (Technical Note ZMR-4-04). The sharp shell of the zebra mussel is razor-like and is a hazard to barefoot swimmers and beachcombers. This combination spoils the most pristine of locations and prohibits recreational activities.
There is also a rising concern for the loss and destruction of certain artifacts of historical significance like the shipwrecks of Thunder Bay in Lake Huron (Black 1999). In the past 125 years, over 100 ships have sunk in or near Thunder Bay, which has created an attraction to the recreational diver. These wrecks are now host to zebra mussel infestation.
