There’s plenty of reasons why dolphins are one of the most beloved aquatic animals on our planet: they have cute smiles, they make adorable sounds, they are benevolent and playful, and their intelligence rivals our own.

Of course, one of the most exciting things about dolphins is the thrill of seeing them in the wild – and because they are usually found out at sea, these encounters are valuable, few and far between.

But the sad truth is that every year around 2,000 dolphins and whales are seen on land. These majestic creatures are found beached – stranded on land – often spelling a painful and drawn-out death, devastating for the creatures and the humans who find and try to help them.

But why does this happen?

For a long time, this has been something of a mystery. But thanks to a group of US-based researchers, we might be closer to understanding this curious phenomenon and its devastating consequences.

According to the study, which was recently published in the journal Communications Biology, the cause of the dolphins’ demise is something that, to many of us, is sadly all too familiar.

In a study of twenty dolphins who were stranded on land in eastern Florida, researchers found something quite unusual when it came to their brains.

All of their brains contained something called BMAA, a kind of cyanobacterial toxin found in blue-green algae that destroys neurons in the brain and can be linked to Alzheimer’s-like symptoms, including disorientation.

And the alarming truth is that dolphins who were stranded during summer, when cyanobacteria blooms and thrives, had 2,900 times the amount of BMAA isomers in their brains than those who washed up out of season.

With this in mind, the researchers concluded that the stranded dolphins were suffering from a form of Alzheimer’s disease, caused by exposure to the toxins.

And this isn’t comfortable reading for humans, since the scientists suspect that cyanobacterial exposure is not only a risk to the neurological health of dolphins; it could be a risk factor for Alzheimer’s in humans too, as Dr David Davis explained in a statement:

“Since dolphins are considered environmental sentinels for toxic exposures in marine environments, there are concerns about human health issues associated with cyanobacterial blooms.”

If this algae-born toxin is having such a disorientating effect on dolphins, it’s understandable that we might be concerned – and all this reinforces the need to avoid untreated water and algae, and keep pets away from it too.

Your health depends on it.

Thought that was fascinating? Here’s another story you might like: Why You’ll Never See A Great White Shark In An Aquarium