Thanks to a novel oceanographic sampling system used in the extreme south of Chile, it was possible to detect a microalgae capable of producing neurotoxic effects in mammals. The research was published in the prestigious journal Progress in Oceanography.

After two years of extensive analysis, the PROFAN oceanographic expedition, which toured the northern part of the Magallanes Region during the second half of 2019, gives its first results. In that campaign, a team of Chilean and foreign researchers carried out an exhaustive study of Harmful Algal Blooms (HABs) in the seas of Patagonia and carried out various samplings in order to scrutinize the diversity of toxic microalgae and bio toxins existing in a very little visited area of the southern fjords.

Using a collection system called SPATT, “Solid Phase Adsorption Toxin Tracking,” scientists found bio toxins produced by microalgae that are generally not detected in Patagonian fjords. Thanks to this technology, rarely used in an oceanographic expedition to the south of our country, the presence of the so-called pinatoxin G was found, a harmful element that, due to its great chemical stability, produces neurotoxic effects in mice. This suggests that it could cross the intestinal barrier causing neurological disorders in animals.

The toxin is generated by a microalgae called Vulcanodinium rugosum, an organism discovered and described in 2012, difficult to detect due to its life cycle. Although it spends most of its time on the seabed, at some point in its development it rises to the surface and secretes pinatoxin G. It is considered a cryptic species, because it is commonly confused with other species with similar characteristics.

Vulcanodinium rugosum © Nézan and Chomérat, 2010

“The discovery of this toxin is a success for those of us who work with red tide, given that it is physically detected for the first time in an oceanographic campaign of these characteristics. This occurred thanks to the implementation of the SPATT system, which allows the absorption of harmful organisms that usually occur in low concentration. The trawl nets that we usually use to detect toxic microalgae do not allow this to be investigated,” explained Marco Pinto Torres, a doctoral candidate at the Center for Dynamic Research of High Latitude Marine Ecosystems (IDEAL), of the Austral University of Chile (UACh).

To date there are no records of intoxication in humans, but its fatal effects on mammals are known. “The task from now on will be to continue monitoring the seas in search of this microorganism in order to cultivate it and study its functioning and response to the production of pinatoxin G in different environmental conditions and mainly in the climate change scenario,” commented the Dr. Jorge Mardones, researcher at the IDEAL Center and the Fisheries Development Institute (IFOP), who participated in the study.

However, the detection of this toxin does not necessarily mean that it is new in the waters of our country, as Dr. Mardones explains. “Many of the species that we have found and which are being reported does not mean they have recently arrived in Chile; we may not have had the analytical capabilities to detect them. Currently, there are more experts immersed in the study of HABs and better technology that allows us to see these events in the water,” he assures.

Following this discovery, which was recently published in the prestigious scientific journal Progress in Oceanography, the team of researchers will continue to analyze the toxin to find out the variables that generate it, its producing organism, seasonality and areas where it is concentrated.

Check the research here.