U.Va. researchers study erosion and rebirth

By Fariss Samarrai

At the turn of the last century and until the mid-1930s, the town of Broadwater on Hog Island, Va., was a popular destination for summer beachgoers and a place where sport hunters shot hundreds of birds per day. Commercial hunters and trappers bagged thousands of ducks and geese for meat, and shorebirds for their plumage. A seemingly endless supply of finfish, crabs, oysters and clams were harvested daily, destined for restaurants and markets in Philadelphia and New York.

Stephanie Gross

Master's degree student Steven Turaski uses a field computer to retrieve water table elevations from below-ground recorders for his studies of groundwater in the salt marsh. His research is helping scientists understand the long-term fate of salt marshes in the face of high rates of sea level rise.

Life for an islander was good, even if the swarms of mosquitoes were thick enough to be called "Hog Island dust."

About 250 permanent residents of Broadwater earned their living on the island. There were more than 80 buildings -- houses, barns, hotels, fish houses, a lighthouse.

Today, none remain.

Most of the sandy wedge of land at the south side of Hog Island where Broadwater once thrived has been washed away by the steady pounding of a rising surf and by winter storms and the passing of autumn hurricanes. Waves -- 14,000 of them -- hit these shores every day, eroding and reshaping the island as they have since long before recorded time.

"After a powerful hurricane in 1936, the second in three years, the residents realized they were fighting a losing battle against erosion," says Bruce Hayden, U.Va. professor of environmental sciences. "The land they were on was melting away like butter on a hot day. They packed their belongings, jacked their houses onto barges, and floated their lives back to the mainland. The community disappeared almost overnight. If you went looking for where Broadwater was, you'd have to look in the sea."

No one lives on Hog Island anymore. Like most of the 13 other low-lying barrier islands on Virginia's Eastern Shore, Hog Island is now part of the Nature Conservancy's 45,000-acre Virginia Coast Reserve. The island is accessible only by boat, after navigating long, narrow channels through the salt marshes and crossing wide stretches of shallow bay. The island is a sanctuary for growing populations of migratory waterfowl, shore birds and song birds.

Hog Island is now a natural laboratory for long-term coastal research funded by the National Science Foundation (NSF). U.Va.'s Department of Environmental Sciences studies barrier island geology and ecology there and operates the NSF Virginia Coast Reserve Long-Term Ecological Research (LTER) project. The project is one of 24 LTERs around the nation conducting long-term environmental studies. The Virginia project is the only LTER investigating barrier island change.

"This is perhaps the best place along the entire Atlantic seaboard to study barrier island geology and coastal ecology," says Hayden, who is lead scientist for the project. "These are some of the most rapidly changing islands on earth."

Scientists at the LTER are monitoring sea level rise, groundwater flow rates, marsh growth and erosion, bay water chemistry, fish and shellfish populations, vegetation and mammal and bird populations.

"The Virginia barrier islands are made up of the finest-grain sand on the east coast," Hayden says.

The sand, an extremely fine-grained quartz, has been roiled by thousands of years of flowing water. It is easily transported by currents from one location to another. A combination of rising sea level, currents, wind, waves, tides and storms shape these islands. They are always eroding and rebuilding, always changing shape.

Understanding the dynamics of barrier island geology on Virginia's largely undeveloped Eastern Shore has implications for the 139 million Americans now living in coastal areas. Governments, property owners and insurance companies are continually wrestling with ways to manage the inevitable erosion of barrier islands. Conservationists are looking for ways to protect these fragile ecosystems while realizing that masses of people will always be drawn to the sea. By studying Virginia's undisturbed islands, U.Va. researchers are gaining insight to the natural processes occurring up and down the coast, and comparing what they see with what is happening on the heavily populated barrier islands in Maryland and North Carolina.

"The rapid change occurring on Virginia's barrier islands allows us to observe a great many conditions over relatively short time periods," says Robert Dolan, a professor in the department, collaborated with Hayden and others on the original proposal to NSF to establish the LTER in 1987. "Change occurs on these islands 10 times faster than at most other coastal areas. Because of this extreme sensitivity to sea level change and weather, we can record how the physical environment -- the geology -- interacts with the ecology. There's no better opportunity to monitor environmental change over the long term,² he said.

Much change has occurred on these islands and in the surrounding waters since colonial days. Although some wildlife were almost wiped out, some are coming back. Many bird species are returning to the islands and are growing in population. Seagrasses are being re-established in some bay areas, and fish, including the prized striped bass, are becoming increasingly abundant.

"We have several experiments under way to monitor and record change and to assess the plants and animals on the islands, in the marshes and in the bays," says John Porter, a research scientist who has been studying small mammal populations on Hog Island since his U.Va. graduate school days in the mid-1970s. "We are trying to understand the processes of change, what role humans are playing in that change and what part is natural. We are seeking answers to questions that would not be possible without long-term research commitment."

This is a shorter version of an article that appeared in the July 2000 issue of Arts & Sciences.