WASHINGTON (AP) -- Federal data shows ranks of scientists who carry out environmental research, enforcement and other jobs fell sharply in some agencies under former President Donald Trump.

Government scientists say many veteran staffers retired, quit or moved to other agencies amid pressure from an administration they regarded as hostile to science and beholden to industry.

That poses a challenge for President Joe Biden, who must rebuild a demoralized work force to meet promises to protect the environment, tackle climate change and reduce pollution.

Hundreds of scientists have left the Environmental Protection Agency, the U.S. Geological Survey and the U.S. Department of Agriculture.

That is hampering everything from enforcing rules against polluters to finishing vital climate research.

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11 Things You'll Find In A 'Typical' Wyoming Home

KEEP READING: 11 Things You'll Find in a Typical Wyoming Home