Rarely have school science fairs, a source of pride and panic for generations of American students, achieved such prominence on the national stage. President Obama held one at the White House last fall. And last week he said that America should celebrate its science fair winners like Sunday’s Super Bowl champions, or risk losing the nation’s competitive edge.

Yet as science fair season kicks into high gear, participation among high school students appears to be declining. And many science teachers say the problem is not a lack of celebration, but the Obama administration’s own education policy, which holds schools accountable for math and reading scores at the expense of the kind of creative, independent exploration that science fair projects require.

“To say that we need engineers and ‘this is our Sputnik moment’ is meaningless if we have no time to teach students how to do science,” said Dean Gilbert, the president of the Los Angeles County Science Fair, referring to a line in President Obama’s State of the Union address last week. The Los Angeles fair, though still one of the nation’s largest, now has 185 schools participating, down from 244 a decade ago.

In many schools, science fairs depend on teachers who shoulder the extra work. They supervise participants and research, raise the money for medals and poster boards, and find judges — all on their own time.