LIHU'E, Kaua'i — A 78-year-old Kaua'i man who shot and killed a pregnant Hawaiian monk seal in May pleaded guilty yesterday to violating the U.S. Endangered Species Act and began serving a 90-day term in the federal detention center on O'ahu.

Charles Vidinha "knew it was a Hawaiian monk seal at the time he fired his (Browning .22-caliber) rifle at her" on May 21 at Pila'a Beach, according to the plea agreement entered before Judge Barry M. Kurren yesterday.

Vidinha told officials that he intended to scare the seal away from the beach, not to kill it, his attorney, federal public defender Alexander Silvert, told The Advertiser yesterday.

Assistant U.S. Attorney Marshall Silverberg, who prosecuted the case, said because Vidinha had never had trouble with the law before and is "broke ... living out of a car essentially homeless, a fine didn't seem to be consistent with justice."

Silvert said his research found other cases of people being sentenced to probation after unintentionally killing endangered species.

"If the government had proof beyond a reasonable doubt that the defendant intended to kill the seal, we would not have done the deal," which included a "special assessment" of $25 but no fine, Silverberg said. "The defendant claims he was just trying to scare the seal because he wanted to go fishing and was just concerned the seal would eat the fish. We have nothing to refute that."

Under the Endangered Species Act, harassing, injuring or killing an endangered species is a misdemeanor, which on conviction can result in a sentence of up to one year in prison, a fine of up to $50,000, or both.

Hawaiian monk seals, which exist only in the Hawaiian Islands, are critically endangered, with an estimated wild population of 1,000. State and federal wildlife agencies are making extensive and costly efforts to help the species survive.

Mimi Olry, Kaua'i's monk seal response coordinator and a veterinarian, said yesterday she finds it hard to believe Vidinha's claim he didn't intend to shoot the seal. She examined the seal's body and found that it was shot once in the chest and once in the abdomen.

Vidinha admitted in the plea agreement that he fired four shots.

The seal, officially identified as K-06, was nicknamed Miloli'i Mom, because she had given birth to several of her five pups on that Kaua'i beach.

"These animals are so critically endangered that the loss, especially of a productive female," is a serious incident, Olry said.

"I'm kind of shocked at what was decided," Olry said of the plea agreement. "This is a critically endangered animal and the second animal shot" within two months on Kaua'i, she noted.

"To me it would seem to incur a greater fine for killing an animal, especially a pregnant animal — she was due to pup any day," Olry said. "Everybody knows you can go up to a seal and go 'Boo!' and they'll go off the beach. You don't have to use a gun."

A 5-year-old male, identified as I-19, was found dead April 20 on a West Kaua'i beach. That case remains under investigation.

According to the plea agreement, "Vidinha deeply regrets his actions and he apologizes to the entire community."

"He didn't even know that he had hit the seal, because the seal swam out into ocean," Silvert said. Later, when Vidinha heard the seal had died, he destroyed the gun because there was "so much publicity, adverse publicity about people being outraged," Silvert said.

"It's pretty clear this was a tragic mistake," Silvert said. "He admitted it, owned up to it and apologized to his family and the community."

Bill Pickering, National Oceanic and Atmospheric Administration law enforcement agent-in-charge for Hawai'i, said yesterday: "We're happy to see the case come to a conclusion and hope it sends a message to other people and the public to not harass the monk seal."

Vidinha has been free on a $10,000 unsecured bond since pleading not guilty in federal court on Aug. 11 and was to stand trial Oct. 14.