“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 science and beholden to industry.

“It’s going to take a long time to undo the damage that the Trump administration has done,” said Kyla Bennett, a former EPA enforcement official who now directs science policy for Public Employees for Environmental Responsibility, a watchdog group. Bennett said many scientists left as Trump’s administration rolled back regulations and undercut climate work, leaving agencies with less experience, a work backlog and unfinished research.”