This story initially appeared in The Guardian and is a part of the Climate Desk collaboration.

Scientist Melissa Miller was seeing one thing in California sea otters that she had not seen earlier than: an unusually extreme type of toxoplasmosis, which officers have confirmed has killed no less than 4 of the animals.

“We wanted to get the word out. We’re seeing something we haven’t seen before, we want people to know about it and we want people working on marine mammals to be aware of these weird findings,” mentioned Miller, a wildlife veterinarian specialist with the California Department of Fish and Wildlife (DFW). “Take extra precautions.”

In March, a examine from the DFW and the University of California, Davis, revealed {that a} uncommon pressure of the parasite, by no means earlier than reported in aquatic animals, was tied to the deaths of 4 sea otters. The pressure, first seen in Canadian mountain lions in 1995, had not been beforehand detected on the California coast.

“This was a complete surprise,” Karen Shapiro, with the UC Davis School of Veterinary Medicine, mentioned in a statement. “The COUG [toxoplasma strain] genotype has never before been described in sea otters, nor anywhere in the California coastal environment or in any other aquatic mammal or bird.”

The extent of the chance to California’s sea otters will not be but clear, however the parasite is regarding, the authors of the examine mentioned, as a result of results it might have on the inhabitants of the threatened species in addition to the chance to different animals. It might pose a public well being danger if it contaminates the atmosphere and marine meals chain, in response to an announcement from UC Davis. The parasite also can infect people.

Scientists are taking a look at a couple of different circumstances that might be tied to the pressure, however received’t know if there’s a connection till additional evaluation is accomplished, mentioned Miller.

The first case dates again to 2020, she mentioned, and the others surfaced in 2022. The otters all appeared to have extreme irritation of the fats all through their our bodies, one thing Miller had not seen earlier than. She noticed excessive numbers of the parasites all through their our bodies, besides for his or her brains. Typically, in deadly circumstances she would see extra of the parasite within the mind.

“That led me to believe these animals died very quickly,” Miller mentioned. This pressure of the parasite, she mentioned, “was behaving in a lot of ways that were different than what we’ve seen before.”

Scientists at UC Davis decided that every one 4 otters have been contaminated with the identical pressure of the parasite, which the workforce discovered was beforehand reported in mountain lions.

Toxoplasma is usually present in cat feces. Otters, which stay alongside the shoreline, will be uncovered to the parasite in rainwater runoff—all 4 circumstances scientists studied got here in in the course of the heavy rainfall season.

Toxoplasmosis an infection is widespread in sea otters—which have a roughly 60 p.c probability of being contaminated of their lifetimes, Miller mentioned—and will be deadly, however this pressure is of specific concern.

However, Miller warned towards unfairly demonizing cats.

“I don’t want this to be a war on cats,” she mentioned. “I have two cats. What I try to do is practice what I preach and what I know as a scientist: I keep my cats indoors all the time and I make sure to dispose of their litter into something that will not leak into the environment.”