The Great Cover-up

From January, 1996 (Update #26)

A marine heritage preservation group in Kingston, Ontario, is currently undertaking a project to photographically record a number of local historic shipwrecks being colonized by zebra mussels. Jonathan Moore, a marine archaeologist and member of the group "Preserve Our Wrecks (Kingston)," is concerned not only with the masking of submerged archaelogical resources by zebra mussels, but also that stripping zebra mussels from the surfaces of these resources will result in damage and the loss of important information. "Byssal threads of the mussel invariably pull off fragments of the material to which they are attached," Moore said. "Repeated cycles of mussel attachment and removal might result in serious damage to the surface of the site. "The lakes, rivers and minor water bodies of North America contain rich archaeological resources from historic shipwrecks to prehistoric habitation sites. These benign freshwater environments can preserve archaeological resources for centuries. The introduction of the zebra mussel to these environments is a challenge to archaeologists and preservationists as zebra mussels attach themselves to historic structures and artifacts." The initial impact of zebra mussel attachment is the loss of "archaeological visibility" - the surfaces of a historic shipwreck can literally disappear under layers of mussels. "Like an historic building covered in ivy, we can recognize its shape, but details of its surface and construction are obscured," Moore said. "If we cannot see, recognize, accurately measure and examine diagnostic features of a shipwreck (i.e., steering mechanisms, machinery, hull construction or fastenings) free of mussels, our ability to study the site is dramatically impacted. The dilemma we face is that the removal of mussels to expose the sources of the site is potentially destructive." Moore would like to hear from others with similar concerns. He can be contacted at Marine Museum of the Great Lakes at Kingston, 55 Ontario St., Kingston, Ontario, Canada K7L 2Y2, or reached via email: jmoore@limestone. kosone.com.

ID: 199601-5.

The Zebra Mussel Update was a 4- to 8-page quarterly national newsletter published by the University of Wisconsin Sea Grant Institute from May 1990 through May 1997. The ZMU documented the spread of the zebra mussel -- an exotic nuisance mussel -- through North America's freshwater environments, especially the Great Lakes, and on efforts to control it.