As the volunteers stream in day in and day out, Mr. Lingenfelser and his unpaid staff stay in touch with veterinarians, including some from SeaWorld, and with researchers and biologists at the NOAA’s National Marine Fisheries Service. Just getting the whales to Key Largo was a multiday process that involved waiting for them to stabilize and then transporting them on a boat equipped with a three-sided berth.

“It’s been a Herculean effort,” Ms. Fougères said.

Not everyone is keen on the mass volunteering effort. Russ Rector, a longtime activist and former dolphin trainer who opposes animal captivity, said volunteers did not always know the risks that working with marine mammals can pose.

Studies have found that marine mammals can transmit disease infection to humans and vice versa. Volunteers are briefed on how to remain still and calm, but Mr. Rector says they are not told enough about the risk of infection and how to protect themselves, a violation of fisheries protocol. The whales have bitten two volunteers and three staff members, some wounds requiring stitches.

Ms. Fougères said that while disease transmission did occur, it was rare.

“Mostly you need to make people aware of the possibility,” she said.

Mr. Lingenfelser said he fully covered the territory in his briefing and barred people who had open wounds or who were ill from going into the water. No volunteers, he said, have reported any illnesses after going home.

A week ago, Mr. Lingenfelser said, displaying scrapes up his arm, he, too, was bitten or “raked.” The baby was trying to be playful, he said.

“It’s nothing life threatening or anything like that,” he said. “But it tends to wake everybody up.”