New airplanes are grounded, investigations of fatal air and car crashes are going undone and scientific studies dependent on government funding have ground to a halt because of the partial government shutdown now in its second week, the Senate Commerce Committee was told Friday.

The economic impact will only intensify as the shutdown continues, affecting everything from the aviation industry to Alaska crab fishermen who may see their lucrative, one-month harvest delayed, witnesses told the panel.

Marion Blakey, CEO of the Aerospace Industries Association, said the shutdown already has all but stopped certification of new aircraft, equipment and training simulators because the Federal Aviation Administration has furloughed more than 90 percent of its employees who work on those issues. Blakey is a former FAA administrator.

New planes are not being delivered to buyers because routine government approvals “essential for our manufacturers to compete and for our industry to grow” are stalled, Blakey said.

Deborah Hersman, who chairs the government’s National Transportation Safety Board, said furloughs have stopped her agency from sending investigators to most air and motor vehicle accident sites, including those with fatalities. Already, she said, the agency has ignored a fatal bus crash that killed eight people in Tennessee, an oil spill site in North Dakota and a small airplane crash in Arizona that killed four people.

“If we don’t go, we don’t know,” Hersman said when asked about the impact of the shutdown on investigations. “So we don’t know what some of those risks are that aren’t being uncovered.”

The NTSB has said it will send investigators to accidents where it believes there are safety concerns that pose a threat to lives or property. That was why the board recently kept investigators on a train collision in Chicago after the shutdown.

But the agency has suspended as many as 1,500 active accident investigations because of the shutdown, Hersman said. The agency has also stayed out of the investigation of a battery fire in a Tesla Model S electric car. Battery fires are a key safety issue for the agency.

Routine NTSB help for the State Department and civil aviation authorities in other countries also has stopped, Hersman said.

Alan Leshner, CEO of the American Association for the Advancement of Science, said the shutdown was “a serious blow to an already beleaguered American scientific enterprise” and could disrupt or halt many studies because grant applications are not being renewed. Even the accuracy of studies could come into question, he said.

Keith Colburn, a crab fisherman featured on the Discovery Channel’s “Deadliest Catch,” said a lucrative, one-month crab season scheduled to begin Oct. 15 is endangered because the National Oceanic and Atmospheric Administration is not assigning quotas to boats and permits during the shutdown.

“Many fishermen and coastal communities are already facing tough times. This unnecessary shutdown may be the tipping point if the situation isn’t resolved soon,” he said.

Sen. Mark Begich, an Alaska Democrat, pressed Colburn on who would benefit if U.S. fishermen are prevented from going to work. Begich said Russians fish for crab and would be happy to fill any gap.

“They’re not waiting around; they’re actually(rooting) for us to fail, aren’t they? Your impact is not just you; it’s multifacted,” Begich said.

“That’s right,” Colburn said.