Bioboxes are traditionally used to provide early warning of zebra mussel biofouling in an area. However, zebra mussels will not always colonize bioboxes. This can lead to the situation seen at the Detroit Edison Power Station, where the biobox indicated zebra mussels were not in the area just before heavy zebra mussel encrustations destroyed the pump providing water to the biobox and clogged raw water lines in the plant (Kovalak et al. 1993).
Bioboxes can be effective if properly designed. Use both filamentous and solid artificial substrates in the biobox and use several types of both substrates. Protect the biobox from weather extremes (keep shaded). Water flow should be kept at about 10L/min. Inspect the flow and make adjustments regularly. Provide a tap for veliger sampling at the incurrent side of the biobox. Sedimentation inside the biobox is a common problem. The artificial substrates must be kept free of sediments for zebra mussel colonization to occur. This may require the addition of sedimentation baffles at the incurrent portion of the biobox and more frequent removal of sediment loads.
Bioboxes are generally not recommended as the sole monitoring method for facilities that can tolerate no zebra mussel fouling. Although bioboxes indicate fouling, they do not always indicate the extent of the fouling; the flow characteristics in these monitors may be either more or less conducive to settlement than in the piping system.
Monitoring of Settled Juveniles and Adults