By Larry J. Schweiger
Pittsburgh Current Columnist
Bald eagles are once again soaring over the skies of Western Pennsylvania. Adult bald eagles are hard to miss with their white head and tail. Their flight is marked by deep, powerful strokes, and when soaring, their flattened 6 to 8-foot wingspans are hard to mistake.
Bald eagles have binocular eyesight that is five or six times sharper than a human’s so they can soar high while searching for food. Some people, seeing an eagle gliding over one of our rivers, may take this sighting for granted. We should not.
Much like the Nation it symbolizes, the bald eagle has had its share of ups and downs. In 1782, Congress selected these majestic birds to be a part of our nation’s seal as they are striking symbols of power and majesty that a young nation sought. At the time, bald eagles were abundant and believed to number about 100,000 birds. Bald eagle numbers started collapsing in the 1940s to 417 nesting pairs by the early 1960s in the lower 48 states. Biologists wondered why.
Austrian chemist Othmar Zeidler synthesized DDT in 1874 but had no practical use for the chemical. In 1939, Swiss chemist Paul Hermann Müller discovered its insecticidal potency. Soon DDT was widely deployed in World War II to control malaria and typhus. Soldiers were given green tin salt-shaker like containers to put DDT on their bodies, in their clothing or their tents. Müller was awarded the Nobel Prize in 1948 “for his discovery of the high efficiency of DDT as a contact poison against several arthropods.”
After the war, DDT was extensively promoted commercially for agricultural and public use. Soon after, bald eagle populations declined catastrophically. It was later proven by scientific research that DDT was bioaccumulating and biomagnifying up the food chain. Nature acts like a vacuum sweeper concentrating DDT residues in birds of prey, causing eggshells of several species of birds to become thin and break. Rachel Carson, a scientist and a respected author turned what scientists had found into a widely read book. For that important work, Carson still gets criticized by the uninformed to this day.
Fifty years ago, a number of Pittsburgh college students experienced an “environmental awakening” during the week of the first Earth Day. As a student at the Community College of Allegheny County, I organized a college biology club field trip to Pymatuning and the Conneaut Marsh to see the last pair of nesting bald eagles in Pennsylvania. We chartered a bus to visit the site. The response to the field trip was so large that we needed to rent a second bus to allow all the students to travel. In preparation for the field trip, students were encouraged to read Rachel Carson’s Silent Spring to better understand the role DDT played in reducing the number of bald eagles to dangerous levels. On the bus, we talked about DDT and its impact on raptors like bald eagles and peregrine falcons that faced a bleak and uncertain future.)
The enormous Conneaut eagle nest sat at the top of a large white oak tree overlooking Pennsylvania’s largest marsh. The nest had been used over many years and accumulated branches and other nesting materials that weighed more than a ton. The nesting tree anchored in shallow swamp soils was leaning under the weight. Visiting with a Game Commission biologist who had earlier inspected the nest, we learned that this endangered pair of bald eagles-the last nesting pair in Pennsylvania-produced two weakened eggs that failed from DDT thinning. My classmates were impressed with these magnificent birds and their huge nest, and at the same time, we were all deeply saddened by their shrinking numbers. For many, it was their first sight of our Nation’s endangered symbol, and they feared that it might be their last.
More than a decade after Rachel Carson published Silent Spring warning of the dangers of DDT and eight years after her death, EPA’s first administrator, Bill Ruckelshaus, was finally able to ban its use in 1972 in the US. A decade after the ban, Pennsylvania eagles had some slow recovery as there were three pairs of nesting eagles in the Pymatuning-Conneaut Marsh region in Crawford County. In 1983, the Pennsylvania Game Commission, an agency funded solely by hunter licenses, launched a seven-year restoration program as part of a federal restoration initiative.
From 1983 to 1989, the Commission’s biologists obtained 88 eaglets from wild nests in the province of Saskatchewan. The eaglets were raised in specially constructed hacking towers and kept in a semi-wild condition. At the same time, personnel provided food until they could fend for themselves in the wild. The Game Commission’s efforts triggered a remarkable recovery as more than 300 bald eagle pairs are now preparing their nests across the Commonwealth for egg laying that should start in February.
As I reflect on the 50 years that span between this day and that first Earth Day, I am reminded that we have made incredible progress in efforts to clean our rivers, to purify our air, to curb acid rain, control toxics and to purchase and protect critical wildlife habitats. DDT has been restricted in this country, and bald eagles, ospreys, and peregrine falcons have come back in numbers sufficient to be removed from the Federal endangered species list. Bald eagles have rebounded so much that the U.S. Fish and Wildlife Service estimated that at least 9,789 nesting pairs populated the contiguous United States. The Commonwealth stopped listing the bald eagle as threatened in 2014.
Landmark environmental laws were enacted at both the state and federal levels. Our rivers have rebounded. Bass are now caught at the West End Bridge at the head of the Ohio River. Bald eagles are returning to Pittsburgh, including at least three nesting pairs in Allegheny County. Last year, a North Park nesting pair joined a Harmer and Hayes nesting sites, and soon more may be found in the region.
There are lessons to be found in the bald eagle recovery. First, we need to apply the cautionary principle before putting any new human-made chemicals into our environment through sound regulation based on rigorous testing and monitoring. Second, we have seen many environmental improvements, but we cannot sit back now. The Trump administration has been systematically rolling the clock back, retreating on nearly a hundred vital environmental protections, including rules controlling climate pollution.
As we approach the 50th anniversary of Earth Day, let’s rededicate ourselves to responsible stewardship and sound ecological regulation to protect our planet and its living resources. A special note to the baby boomers who may have taken part in that first Earth Day. Our children and grand children’s future is clearly threatened by our mismanagement of the environment and by our continued dependence on coal, oil and more recently fracked gas. We must give voice to confront an uncertain future by demanding a clean energy future. The generation that heralded the first Earth Day must rekindle our zeal for our children’s future before it is too late.