More than a dozen dolphins that stranded on the beaches of Florida and Massachusetts, have been found with a brain full of amyloid plaques, a hallmark of Alzheimer's disease.
Scientists made the discovery believe it may be a warning for all of us: with Alzheimer's disease is plaque, the team also found an environmental toxin BMAA.
Made of blue-green algae blooms, the neurotoxin is easily caught up in the food of the ocean, and chronic exposure has long been suspected that the cause of neurological diseases, including Alzheimer's, Parkinson's and amyotrophic lateral sclerosis (ALS).
The presence of both BMAA and amyloid plaques in 13 stranded dolphins now adds even more weight to this hypothesis.
"Dolphins with & # 39 are excellent sentinel species to toxic substances in the marine environment," says neuroscientist Deborah Mash of the University of Miami.
"With the increase in frequency and duration of cyanobacterial blooms in coastal waters, dolphins could provide early warning of toxic effects that may affect human health."
They can also be a good animal model as BMAA may cause Alzheimer's disease. In 2017, it was found that dolphins with & # 39 are the only known wild animals to show signs of this common human diseases.
At the same time, the dolphins that inhabit the coastal waters of Florida are also often exposed to repeated harmful algal blooms (HABs). It may just be a coincidence, but experiments have shown that chronic dietary exposure to BMAA can cause neurodegenerative changes in humans and primates.
"Acute and chronic exposure to these toxins may be harmful to humans or animals as a result of respiratory diseases, acute dermatitis, mucosal damage, cancer, multiple organ failure and death," the authors write.
As the world warms rapidly, the HAB is only becoming more frequent, and the authors fear that the dolphins will accumulate even more BMAA in the end, "how under the influence of B and swallowing prey previously exposed cyanotoxin"
Thus, these creatures may very well be our first indication of poor environmental conditions, and while it is still not clear when these flowers directly cause Alzheimer's disease in dolphins or humans, the researchers say that it is a risk that we should not be willing to accept,
"For $ 64,000 question is felt whether these marine mammals cognitive deficits and disorientation that led to draw them to the shore," said co-author Paul Alan Cox, ethnobotany Labs in brain chemistry in Jackson Hole.
"Until further research clarifies the issue, people should take simple steps to avoid exposure to cyanobacteria."
The study was published in PLoS ONE.