On the verge of being wiped out 40 years ago, bald eagles have made a remarkable comeback in New Jersey, with record numbers of nests and young eagles reported this year.

Of the 238 eagle nests that were monitored by a small army of volunteers, 189 had eagles that laid eggs, up from 185 last year.

The big jump came in the number of chicks that survived their first weeks of life and gained enough strength to fledge or fly. There were 248, up from the previous high of 216 three years ago.

The numbers were made public this month by the Conserve Wildlife Foundation of New Jersey, whose staff and volunteers work with state government biologists to conduct an eagle census.

"This was a banner year," David Wheeler, executive director of the foundation, said Tuesday. "It's not surprising that we reached another milestone, because the long-term trend shows an increased population."

In a state that has been maligned by industrial pollution and is often the butt of unflattering jokes, the return of bald eagles represents a significant bellwether for a recovering environment.

By contrast, only one active nest existed in the entire state in the 1970s and early 1980s. Government officials, biologists and environmentalists credit the rise of the population nationwide to the 1972 ban of the pesticide DDT, which caused eggshells to be thin, killing chicks long before they hatched.

Environment:Hey land-lovers, if you're in NY or NJ you can whale watch from the shore this fall

Lowry:From the Meadowlands to the Badlands, the Endangered Species Act is now endangered

Editorial:In salute to all New Jersey’s proud birds of prey

Another factor is the Clean Water Act, which helped cut down on sewage discharges and runoff into rivers, streams, bays and other water bodies.

Cleaner water restores the food chain. It allows for more tiny crustaceans, leading to more fish, leading to more birds. Eagles primarily eat fish, and they build their nests only in spots where the food supply is abundant.

Bald eagles were removed from the federal endangered species list in 2007 but are still on New Jersey's list.

They can now be seen across the state, from the Palisades and the Highlands to the Jersey Shore and the banks of the Delaware River. Birders in the Meadowlands have reported seeing as many as 60 eagles in one day, most of them perched on a tree in Little Ferry.

The story continues after this photo gallery:

"The really great thing is that you can see eagles now in a place like the Meadowlands, which you really never thought would come back the way it has," Wheeler said of the region's emergence as a top birding spot. "Its success mirrors that of the eagles."

Eagles even built a nest in Paterson in recent years, surprising birders because the city is so densely populated and has a long history of post-industrial pollution. When an eaglet hatched there last year, it was celebrated as an example of how far the species had bounced back. But the bird died in August 2018 after volunteers found it weak and on the ground.

Details and approximate locations of the 2019 eagles' nests won't be made available until an annual report by the state Division of Fish and Wildlife is released in December.

But the vast majority of nests are in the southernmost parts of New Jersey along Delaware Bay.

"It's really the best area for them," Wheeler said. "It's remote. There's not a lot of people around there. And there is plenty of prey."

Flying high

The bald eagle population in New Jersey has grown steadily over the past four decades. Two key measures are used: the number of nests populated by a pair of mating eagles and the number of chicks that survive long enough to have the strength to fly.

Nests Number of young

1982: 1 1

1985: 1 2

1990: 4 5

1995: 11 19

2000: 23 30

2005: 48 64

2010: 82 69

2015: 150 199

2019: 189 248

Source: New Jersey Division of Fish and Wildlife