Two endangered Hawaiian monk seals have died on Oahu, a fresh blow to a species already struggling to survive.

• A three-month-old pup drowned after getting tangled in an abandoned fishing net left in the water off a west Oahu beach.
• A one-year-old seal named Umei Umei died from toxoplasmosis, a parasite disease — the second seal lost to it this year.
• The parasite breeds in cat intestines and spreads through their feces into the environment and ocean.
• There is no vaccine and no cure, so keeping seals safe comes down to prevention.

Outlook: With no treatment available, more seal deaths are likely unless fishing gear is cleaned up and the spread of the cat parasite is reduced.