There is something deeply wrong if dolphins, the most intelligent animals after us, are developing Alzheimer’s. Yet it really happens: a group of researchers analyzed the brains of twenty specimens found stranded in the Indian River Lagoon, Florida, and discovered lesions identical to those of human Alzheimer’s patients.
Amyloid plaques and tangles of tau protein accumulate in their brains, the same signs that in humans indicate neuronal degeneration. The difference is that dolphins can’t tell it. They just lose their bearings, swim in circles, until they end up face up in the sand. And the cause is no mystery: it’s the water. Or rather, the dirty, overheated water that surrounds them.
The toxic algae that drives them crazy
Scientists have found a substance with a complicated and disturbing name in the brains of dolphins: 2,4-diaminobutyric acid (2,4-DAB). It is a neurotoxin produced by cyanobacteria and harmful algae, which proliferate in polluted seas when temperatures rise. During the algal bloom season, the levels of this toxin in dolphins were almost three thousand times higher than during “quiet” periods. In practice, every time the sea “blooms”, they poison themselves.
2,4-DAB overstimulates neurons to the point of burning, derails a key enzyme that regulates brain activity, and alters over 500 genes related to nerve function. The result is terrible: tremors, disorientation, chaotic behavior. In short: a form of aquatic dementia.
Scientists think that many dolphins become stranded precisely because they no longer understand where they are. They are not mentally ill: they are victims of our pollution.
Climate and pollution: the perfect storm
Florida’s waters are among the warmest and most nutritious on the planet. An ideal cocktail for toxic algae blooms, which are now not limited to a few summer weeks but last for months. Pollution from agricultural and industrial waste feeds the algae, the heat multiplies them.
And so the sea turns into a neurotoxic soup in which every form of life begins to fail. Fish, molluscs, crustaceans and now even dolphins accumulate these substances. Those at the top of the food chain — guess who — risk suffering the consequences. Dolphins are considered a sentinel species, a wake-up call for what is also happening inside us. If their brains deteriorate from toxins, it’s a short step to humans.
Some studies have already found traces of the same substances in human brains affected by Alzheimer’s. It doesn’t mean that algae will make us forgetful overnight, but that we are breathing, eating and drinking a sick environment. And if the sea loses its memory, we will soon lose it too.
You might also be interested in:
