The head of the Department of Land and Natural Resources described the latest monk seal death as a "despicable act" as the reward for information grew to $40,000.

It was the fourth monk seal to die under suspicious circumstances since November.

Director William Aila Jr. held a news conference Wednesday to call for the public’s help for any information relating to the death of a 3-year-old monk seal identified as RA16. The seal, nicknamed "Noho," was found dead Sunday on Kauai.

Animal protection groups including the Humane Society of the United States on Wednesday added another $10,000 to the financial reward they’re offering for information leading to the arrest and conviction of people killing the seals. The reward now stands at $40,000, or $10,000 per seal.

Aila would not divulge specific details on Noho’s death due to the ongoing investigation.

It was the second monk seal killing to occur in northeastern Kauai since January.

Two other monk seals that died of suspicious circumstances were found on Molokai. An adult male, RR64, was found in mid-November and a juvenile female, RT40, in late December.

Volunteers have since heightened patrols.

"There are more eyes and more eyes at more times of the day out there," Aila said.

Hawaiian monk seals are designated as a federally endangered species, with 1,100 in the Northwestern Hawaiian Islands and about 100 in the main Hawaiian Islands.

Killing a Hawaiian monk seal is a class C felony under state law, punishable by up to five years in prison and a $50,000 fine. It is also a federal crime.

Aila said there are some people associated with fishing who view monk seals as an invasive species.

"People who are opposed to monk seals, they don’t have a choice," he added. "The seals are here to stay. We have to find a way to have mutual respect for each other."

More than a dozen animal protection, environmental and Native Hawaiian community groups recently formed a coalition called the Aloha Kanaloa Coalition to raise awareness about the plight of the Hawaiian monk seal population and to help promote coexistence.

Anyone with information on the killings can call the toll-free, confidential tip line at 1-855-DLNR-TIP.