SAN FRANCISCO — Scientists are concerned by a massive shark die-off in San Francisco bay, but are unable to get state funding to research the exact cause.
NBC Bay Area reports that two thousand leopard sharks and hundreds of bat rays, smoothhound sharks, striped bass, and halibut have turned up dead on San Francisco Bay between February and July this year.
The culprit is suspected to be a parasite known as Miamiensis avidus, which enters the shark's nose and eats away at its brain.
When the animal eventually succumbs to the parasite, it either swims aimlessly in circles or beaches itself.
But scientists say only a small fraction end up on shore. Sharks aren't naturally buoyant, so the infected ones sink to the bottom of the ocean once they stop swimming.
Leopard sharks are the most commonly spotted victims of the parasite, but it's a lesser concern for the California Department of Fish and Wildlife, since the species is not endangered.
Scientists fear, however, that other species are also becoming infected and dying, but just aren't washing up on shore. They also worry that the parasite could spread farther along the California coast.