Polluting factories go uninspected by the U.S. Environmental Protection Agency. Leadership positions sit vacant at the U.S. Geological Survey's climate science centers. And U.S. Department of Agriculture research into environmental issues important to farmers is unfinished.

The ranks of scientists who carry out environmental research, enforcement and other jobs fell in several agencies — sharply in some — under former President Donald Trump, federal data shows. Veteran staffers say many retired, quit or moved to other agencies amid pressure from an administration they regarded as hostile to sc...