The wounds were grimly familiar to conservationists: Another sea lion had been shot.

Rescuers found the yearling struggling at a popular surfing spot on California’s Newport Beach. One wound — probably from a pellet gun, they found — had left her with a painful abscess. A second projectile was lodged between her ribs.

A volunteer at the Laguna Beach non-profit Pacific Marine Mammal Center named her Mandalorian, inspired by a binge-watch of the hit Star Wars TV show. And for a week in December, the young sea lion got treatment among fellow rescues Yoda, Leia and Skywalker.

But her health kept deteriorating, the centre said this week, and eventually the staff made a “difficult decision.” Mandalorian was euthanized.

Her injuries are part of an alarming pattern for wildlife advocates, who have tracked violence against the flippered, barking marine mammals for years. They say fishermen in particular have targeted animals they view as a threat to their salmon hauls.

“Unfortunately, what we saw is taking place up and down the Pacific Coast,” said Peter Chang, the centre’s CEO, in a statement. “These are disgusting and intentional acts, many of which are premeditated.”

The issue goes beyond sea lions. The same day Pacific Marine Mammal Center announced its decision to euthanize Mandalorian, federal officials posted a $20,000 reward for information in the shooting death of a northern elephant seal. The creature was discovered along a scenic highway with a wound to the chest and its tail fins sliced off.

A decades-old federal law called the Marine Mammal Protection Act makes it illegal to hurt wild animals such as sea lions. By some measures, the legislation has been successful: The National Oceanic and Atmospheric Administration announced two years ago that California sea lions had “fully rebounded” under its oversight, after threats such as hunting and pollution cut populations in the 20th century.

But threats of fines and up to a year’s imprisonment have not stopped people from shooting and stabbing hundreds of West Coast sea lions between 1991 and 2016. The few investigations that led to charges have all involved fishermen, National Geographic reported in 2018.

Many people “feel like they are competing with the sea lions for the same resources,” said Chang from the Pacific Marine Mammal Center.

It’s not clear who targeted Mandalorian. The two pellets removed from her body will aid further investigations at NOAA, the centre said.

Staff are hopeful that Yoda, Leia and Skywalker will recover and be returned to the wild.