The Hudson Valley of New York, in the northeastern United States, is one of the most complex and diverse river ecosystems in America. Striking the proper balance between public use and protection of this unique natural resource is a major challenge. That is the focus of Hudsonia, a nonprofit organization that promotes scientific research, policy analysis and better public understanding of the Hudson River environment. VOA's Adam Phillips reports.  

It is nearing sunset, and Erik Kiviat peers through his binoculars at the riot of animal and plant life on Tivoli South Bay. The 100-hectare bay is a small inlet off the Hudson River, the great eastern New York state waterway that flows more than 500 kilometers south out of the Adirondack Mountains, through the state capital at Albany, on to New York City's harbor, and out to the Atlantic Ocean.

Kiviat, a biologist, is cofounder and director of Hudsonia.  From his place within the reeds, he sees a complex natural ecosystem: great egret birds, small killifish, dragonflies, beetles, frogs, wild rice, bulrushes, yellow iris and scores of other animal and plant species. He also sees train tracks, river barges and other signs of the Hudson River's important role over the past three centuries as a major commercial artery.

Kiviat points to the water chestnut leaves covering most of the bay's surface as an example of how human activities have changed the river's ecology.

"It's been in North America for maybe 150 years, and it does very well in these shallow, sunny, nutrient-rich alkaline bodies of water that are so common around human habitations," he says.

Kiviat adds that the successful acculturation of so-called "invasive" species, like water chestnut and spatterdock, has been accelerating in recent decades due to the globalization of commerce and other human activities that transport plants and animals and fungi back and forth from one part of the world to another.  

Kiviat's organization is dedicated to two separate yet allied purposes: solid environmental research of the Hudson watershed and the enlightened use of the region's environmental resources. The two often appear to conflict. For example, Kiviat acknowledges that people often are upset by any visual change to a landscape with which they are familiar. On the other hand, change is a given in any natural environment. Sometimes that change is slow. Sometimes it is abrupt. 

Kiviat knows well that public responses to any change can vary widely. For instance, those who love the aesthetic quality of open water may dislike the blanket of water chestnuts that has covered most of Tivoli South Bay over the past half century. Recreational fishers, on the other hand, know that the underwater stems of the water chestnut are a favored habitat for snails, insects and other invertebrates, which help to attract fish.

"And at the same time," says Kiviat, "[due to the density of the plant's stem systems] there isn't much dissolved oxygen under that water chestnut in the summer. So the fish can't get in there very effectively to eat all that good stuff that's in there waiting for them."  

Kiviat adds that just as human actions over the years have disturbed the Hudson ecology, they can also help now to bring it into better balance.  Kiviat and some of his scientific colleagues who are interested in Tivoli South Bay say it should be possible to break up its 90 hectares of water chestnut into smaller patches interspersed with shallow open water.

"That way," he says, "we would, in theory ? get some more dissolved oxygen into the water, make some space for fish, let the fish get into all that good food that's in the water chestnut, and then let people who fish ? the fishers ? get to the fish." 

Hudsonia scientists conduct extensive field research up and down the river, often with the assistance of environmentally conscious local volunteers. That fieldwork forms the basis of the group's recommendations for more sustainable and responsible management of the Hudson.  Still, Kiviat emphasizes that Hudsonia is not an advocacy organization in the sense that they don't take sides in land-use planning controversies.

"We don't say 'This is a project that should or shouldn't be built on this particular site,'" he says. "We try to take good scientific data about our environment and about people, and then we use that information to help people do a better job of doing the things their community values." 

Hudsonia is doing that through its Biodiversity Resources Center. The center creates detailed habitat maps that help local policy-makers and the public in town development and conservation planning.  Hudsonia's research and education division keeps a watchful eye on the area's wetlands and waterways.It also supports preservation efforts for threatened species, such as the Blanding's Turtle

Still, challenges such as climate change, invasive species and human-caused contamination continue to threaten the ecology of the Hudson Valley region. While good science and timely planning may help mitigate the worst dangers, prospects for the overall health of the Hudson Valley are uncertain.