Understanding Paralytic Shellfish Poisoning (PSP)

Paralytic shellfish poison (PSP) is a dangerous neurotoxin produced by certain algae. It accumulates in shellfish that consume these algae, posing severe health risks to humans who eat contaminated shellfish.

PSP comprises several toxins, mainly saxitoxins. These toxins block sodium channels in nerve cells, preventing normal cellular communication and leading to paralysis. Remarkably, saxitoxins are among the most potent natural toxins known.

One of the earliest recorded PSP outbreaks happened in the 18th century in Canada. Indigenous peoples used clams as a staple food, and many suffered severe illness or death during specific seasons when PSP levels spiked.

Modern techniques for detecting PSP include mouse bioassays and high-performance liquid chromatography. Public health agencies closely monitor shellfish harvesting areas, issuing closures when toxin levels are dangerous, thus preventing human consumption of contaminated shellfish.

Climate change is exacerbating PSP issues. Warmer waters and nutrient runoff increase harmful algal blooms, elevating PSP risks. Understanding and mitigating these changes is crucial in managing future PSP outbreaks and protecting public health.

Some freshwater fish have been found to carry PSP toxins, challenging the notion that this toxin is restricted to marine environments.