The lawyer for a tourist accused of hurling a rock at an endangered Hawaiian monk seal says his client was trying to protect sea turtles and has since been assaulted, threatened and doxed.

Igor Lytvynchuk, 38, of Covington, Washington, is scheduled to appear in court in Honolulu on Wednesday on charges of harassing and attempting to harass a protected animal.

Earlier this month, a witness recorded what prosecutors say was a video of Lytvynchuk throwing the rock at a Hawaiian monk seal at a Maui beach. He later made arrangements to surrender in the Seattle area as special agents with the National Oceanic and Atmospheric Administration (Noaa) were seeking to arrest him, prosecutors said.

The video drew widespread condemnation and demands for prosecution in Hawaii, including from Maui’s mayor, Richard Bissen. Scientists identified the seal as an adult male known as R404, according to Noaa.

In a separate video statement, the mayor said the monk seal was “not just a seal to us … [but a] part of our ocean ‘ohana in Lahaina”.

“Many of our residents know her, watch over her and care deeply about her wellbeing. In fact, members of my team in Lahaina have been tracking and looking out for her for some time now,” Bissen said.

He called Lytvynchuk’s alleged behavior “unacceptable”, saying: “As mayor, I not only have a responsibility to protect the people of Maui county, but also the wildlife animals that share these islands with us. Our connection to the ocean, the land and the creatures that call Hawaii home is part of who we are.”

According to prosecutors, a state department of land and natural resources officer investigated a report of Hawaiian monk seal harassment in Lahaina, the community that was largely destroyed by a deadly wildfire in 2023. A witness showed the officer a video of the seal swimming in shallow water when Lytvynchuk threw the rock, described by a witness as the size of a coconut, directly at the seal, narrowly missing its head, prosecutors said in a criminal complaint.

When a witness confronted Lytvynchuk, he said “he did not care and was ‘rich’ enough to pay any fines”, according to the complaint.

Afterward, a man “brutally assaulted” Lytvynchuk, his attorney, Myles Breiner, told the Associated Press. Lytvynchuk declined to file a police report on the assault, the attorney said.

Breiner explained his client had been to Hawaii previously and was familiar with sea turtles, but not Hawaiian monk seals. Lytvynchuk is a fisher and thought the seal was an aggressive sea lion, the lawyer said.

“So his response was not to hurt this monk seal, but to get it away from the turtles,” Breiner said.

The incident shows Noaa must do more to educate the public about protecting Hawaiian monk seals, said Brian Schatz, the US senator for Hawaii, in a statement.

Since the video surfaced, Lytvynchuk has faced death threats and doxing, including receiving a package at his home containing what appeared to be feces, Breiner said.

He said his client was being treated unfairly because he was a white outsider. “The vast majority of attacks on monk seal and turtle are by locals,” he said.

Known in ancient Hawaiian as “ʻīlio holo i ka uaua”, meaning “dog that runs in rough water”, the seals are endemic to the Hawaiian Islands. They typically hunt for food beyond the immediate shoreline, diving in waters between 60 and 300ft deep in search of fish, octopus and crustaceans.

Hawaiian monk seals were hunted to the brink of extinction during the 19th century. One of the world’s most critically endangered marine mammals, they continue to face a wide range of human-driven threats, including habitat loss caused by coastal development, pollution and rising sea levels linked to the climate crisis.

They are also vulnerable to entanglement in fishing gear such as hooks and commercial nets, while diseases associated with inland water runoff further threaten their survival.

Lytvynchuk is charged with violations of the Endangered Species Act and the Marine Mammal Protection Act.

If convicted, he faces up to one year in prison for each charge. He also faces a fine of up to $50,000 under the Endangered Species Act and a fine of up to $20,000 under the Marine Mammal Protection Act.