A parasite spread by cat poop is causing a big problem for endangered sea otters in California, and researchers have finally figured out how.
!ADVERTISEMENT!
Sea otters were nearly wiped out by the fur trade at one point, but they've been slowly making a comeback thanks to conservation efforts and protection under the Endangered Species Act. While they're on the road to recovery the latest numbers from the U.S. Geological Survey released last month shows they're population growth has stalled, with the biggest issue being that they're dying in record numbers.
Scientists believe the losses could be due to a number of factors that include a lack of food, pollution, parasitic worms, toxic algal blooms and shark bites, but another threat to their survival is Toxoplasma gondii, a parasite that only reproduces in cat species, including house cats. According to the Sea Otter Alliance, an estimated 17 percent of sea otters are dying from a brain disease that it causes.
While scientists have known this is a problem for sea otters, they didn't know exactly how a land-based parasite was infecting them in the water until now. Building on previous research that found T. gondii infections were more common in sea otters who ate marine snails than those who ate abalone or other foods, researchers from the University of California, Davis started exploring the link.
They found that the kelp, or seaweed, marine snails eat is coated with sticky, invisible polymers – basically a nice layer of slime – which acts like a glue that collects the parasite's eggs, which the snails then eat as they graze. The eggs then get passed up the food chain when the sea otters eat the snails. The results of the study were published this month in the journal Proceedings of the Royal Society B.
"Discovering the role that these invisible polymers play in disease transmission in the ocean is a tremendous step forward in helping us better understand and mitigate the impacts of coastal water pollution on the health of wildlife and humans," said lead author Karen Shapiro, a research scientist in the School of Veterinary Medicine.
Continue reading at ENN affiliate, Care2.
Sea otter image via Shutterstock.