Fossil digs don't endanger Calvert Cliffs

September 22, 2010

The September 15 letter about the removal of fossils from Calvert Cliffs by Phyllis Bonfield and Marcia Seifert (Readers respond) provides a good opportunity to clarify how the Calvert Marine Museum goes about that work. Their concerns are varied and will be addressed in the order in which they appear in their entry.

Their first concern was for our safety, which is a legitimate concern and one that we take great care to address. The cliff in the immediate area where this skull was removed is approximately 20 feet high. The day before the students from Harrisburg University arrived to quarry the skull, we visited the site to ensure that they would be safe working there. Museum staff will never dig, nor allow others under our supervision to dig, on a skull in a section of cliff that is unstable or presents imminent danger. There have been skulls that we have not excavated for that very reason. I would also like to make it clear that the students had approached us for the opportunity to participate in the dig; we never solicit help.

Ms. Bonfield and Ms. Seifert also express concern "…with the museum's ability to excavate in the cliffs without official permits … indeed, with only the permission of the homeowner." Their concern is based on misinformation. We comply with all governmental legislation and regulations when we excavate fossils from along Calvert Cliffs and elsewhere. Maryland Critical Areas permits are required when the disturbance exceeds 5,000 square feet and 100 cubic yards or more. The disturbance we create in removing a fossil is far below this threshold. Following most of our excavations, we backfill the hole in the cliff with a mixture of cement and sediment that was removed from around the fossil. This plug looks very much like the original cliff face and because of its cement content is more resistant to erosion than the host sediment surrounding it. Consequently, our excavations do not weaken the cliffs; neither do they accelerate or precipitate cliff collapse. What is inevitable, whether we excavate and back-fill the hole or not, is that ongoing cliff-wide erosion fairly soon wipes away evidence of our presence.

They further state: "It is time for government officials to institute shoreline erosion control measures, stabilize the cliffs, preserve land values, and help stop sediment from polluting the Chesapeake Bay." This broad proclamation moves the argument away from the preservation of fossils into the domain of public debate. How much would it cost to prevent cliff erosion? The Community Association of the Chesapeake Ranch Estates, where Ms. Bonfield and Ms. Seifert live, commissioned Ryan and Associates, a professional engineering firm, to give them a cost estimate to do just that. Ryan and Associates concluded that it would cost approximately $2.86 million per 100 linear horizontal feet to stabilize the cliffs. There is a minimum of 5,000 linear horizontal feet of cliff face in the Chesapeake Ranch Estates, resulting in a cost of $143 million to stabilize the cliffs in their community. To apply the Ryan and Associates standard to the rest of the cliffs along Calvert County would cost approximately $56 billion, presumably of taxpayers' money. Chesapeake Bay pollution is largely due to excess nutrients influx, not sediments eroding naturally from the cliffs.

While it is easy to understand why Ms. Bonfield and Ms. Seifert are upset by the threat to their property, they fail to grasp the larger implications of their request. One does not restore beaches by stabilizing the cliffs. The sandy beaches in Calvert County exist and are being nourished in part because of cliff erosion. If it were possible to stop or slow the cliffs from eroding, natural and ongoing shoreline erosion would soon remove the sand from our beaches. With no naturally eroding source from which to replenish it, there would be no beaches for the thousands of people who now enjoy them. Although Ms. Bonfield and Ms. Seifert are focused on their personal desire to stabilize the cliff, they might take a moment to appreciate the environmental importance of both naturally eroding cliffs and undisturbed beaches. Revetments destroy cliff habitat of the endangered tiger beetles, not to mention destroying the sandy beaches in which horseshoe crabs spawn and on which many other species rely. These are complex interrelated natural systems that we destroy at our own peril.

I am proud of the work that the Calvert Marine Museum does to preserve the paleontological resource along Calvert Cliffs and for our efforts to conserve natural habitat and aesthetic beauty that benefits all residents. Beyond preserving priceless fossils, we use this resource to educate aspiring students about earth history, life in the past, and our place in this dynamic ecosystem. We celebrate the beauty and the natural wonder that the cliffs represent — as they exist and change through time.

I conclude with a quote made by Ms. Seifert in 2005 to the Washington Post in regards to her home perched atop the cliffs: "It's a million-dollar view," Seifert said. "And when the house slides into the bay, oh well."

Stephen J. Godfrey, Solomons

The writer is curator of paleontology at the Calvert Marine Museum.

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