Scientists have determined that the death of a spinner dolphin found off Hawaii Island last year was caused by a parasite-borne disease that has threatened Hawaii’s monk seal population.
The death is the first documented case of toxoplasmosis killing a spinner dolphin in more than 25 years. Toxoplasmosa gondii is a parasite that is primarily spread by cat feces, Hawaii News Now reported.
Kristi West, associate professor of biology at Hawaii Pacific University and the director of the state’s marine stranding program, said the recent lab results are a concern for Hawaii conservationists. West and her team are responsible for determining the cause of death for all whales and dolphins that die in Hawaii waters.
She said her lab will conduct further testing of dead spinner dolphins that were never tested for toxoplasmosis to see if the disease poses a larger threat to the animals.
“It’s really concerning for us,” West said. “Is this a population threat to spinner dolphins like it is for Hawaiian monk seals?”
Last year, a monk seal that died near the Ala Wai Boat Harbor tested positive for Toxoplasmosa gondii. The disease has now been blamed for the deaths of at least eight Hawaiian monk seals.
Toxoplasmosa gondii is common in both feral and household cats in Hawaii.
“The vector is really cat feces that get into the watershed, and it’s very persistent,” West said.