University of Delaware Office of Public Relations The Messenger Vol. 5, No. 2/1996 Champion of Delaware's coastal wetlands As a youngster, he hunted and fished in the wetland marshes near his home on the outskirts of New Castle, Del. These days, Dave Carter, Delaware '85, works with the Department of Natural Resources and Environmental Control (DNREC) in Dover, Del., to protect the marshes he loved as a child. After graduating from the University of Delaware with a degree in biology, Carter intended to join the Peace Corps, but a summer job with DNREC turned into a seven-year stint with the Division of Fish & Wildlife, overseeing mosquito control operations. While there, he tried to find alternative methods to potentially harmful insecticides by introducing mosquito-eating fish and insects. For the past three years as environmental manager for the state's coastal management program, he has tried to protect Delaware's fragile coastal areas. Currently, he's "doing some highly technical work with specialized water quality sampling, stormwater sampling and computer modeling" and can often be found slogging through the marsh grasses, supervising his team of engineers and biologists as they gather data about water birds and water quality. Under Carter's jurisdiction are 30 to 40 wetland sites encompassing some 10,000 acres along the Delaware and Christina rivers, including the heronry on Pea Patch Island on the Delaware River. Pea Patch Island is surrounded by waters containing large amounts of industrial and municipal waste and is directly affected by oil spills. Yet, it supports the largest East Coast heronry north of Florida, attracting as many as 24,000 herons, egrets and ibis each spring. How does this area maintain a healthy, stable population of wading birds? "We really don't know for sure what factors make it such a productive habitat for them," says Carter, "and without knowing that, we're always at risk of losing them." Developing baseline data on this fragile area is part of Carter's responsibility. "On Pea Patch Island, we're taking a good look at the environmental and habitat needs of different species. We're using the heron as one of the indicators of the regional ecosystem," he explains, "because it's so dependent on a much larger region." Another of his tasks is to use the data to formulate policy that will keep not only the heronry but the entire ecosystem healthy. With the heron's minimum survival requirements in mind, land use can be planned so that areas critical to the species' survival will be protected. Land-use policy, he says, is often shaped by political needs and deep-rooted social values, which can be hard to change. Dealing with differing opinions has been one of the challenges in his work. It has entailed, for example, working one-on-one with landowners around the town of Port Penn, listening to their concerns and educating them about adjusting water levels. Such an education process is critical, he says, since most remaining land needing ecological management is privately owned. "If we're going to make true ecological strides, we've got to be able to deal with people on their own private lands," explains Carter. But, Carter says his biggest stumbling block right now is a shortage of scientific knowledge. "Most of the big problems have been fixed," he says. "The problems we're looking at now are harder to define. It's easy to identify a primary source of pollution, but not so easy to find the secondary sources. We're trying to get a better handle by doing some good monitoring, but the science still needs to be developed in a lot of fields." Lack of knowledge also can be disastrous for highly sensitive water bird populations. At the Thousand Acre Marsh south of Delaware City, where water level is adjusted by tidal gates, "what we think are relatively minor changes in water level have a drastic impact on the water birds," says Carter. "If you manipulate the water level, and it's too deep and they can't catch fish in it as well, they have to go somewhere else." Sometimes, it's a choice of which species to protect. At the Armstrong heronry south of Port Penn, the arrival two years ago of a single nesting pair of bald eagles caused the entire heron population to leave. "Should we protect the bald eagle, an endangered species, at the expense of the entire heronry? It's an environmental trade-off," he says. In wetlands management, there are no easy answers. The invasion of the exotic grass phragmites in many marshes has limited the growth of more diverse native vegetation better suited to supporting wildlife. But, the common practice of using herbicides to control the phragmites may harm the birds more than it helps. "One of the concerns that has stuck with me," says Carter, "is that we call it restoration and we spray phragmites and we get different vegetation in. We definitely make changes to the marsh. But, is it necessarily good and for the best? When I look at it from a regional perspective, I don't know." Weighing the conflicting interests of wading birds, shore birds, waterfowl-and people-is one of the challenges of Carter's job. Although current knowledge of how to best manage wetland areas may be incomplete, Carter's philosophy is to proceed with what we know now. "We really have to continue with good faith on the current track to restore the wetlands and be prepared to change our direction as we get better data," he says. "Mistakes may be made, but the alternative is to do nothing. If we find down the road that what we're doing isn't working, we can correct our mistakes then." Ultimately, he says, he'd like to leave the areas he's worked on in better shape for the next generation. -Valerie Baddorf