After 11 years of study, a team of scientists detected six varieties of the genus Pseudo-nitzschia in the fjords and channels of Patagonia, one of which is associated with the generation of harmful substances for consumption.

Harmful Algal Blooms (HABs) in the Magallanes Region are a phenomenon that occurs with particular frequency. Over the years, researchers have been able to study the organisms that cause these alterations in the system and the effects they have on the marine biodiversity of Patagonia.

One of these is the genus Pseudo-nitzschia, a particularly complex group to analyze due to its characteristics and size. HAB monitoring programs in Chile had only detected and worked under three species (P. australis, P. pseudodelicatissima and Pseudo-nitzschia spp.) However, a recent study revealed the biological diversity of species present in this geographical area.

A multidisciplinary team of researchers produced the first report on the diversity and distribution of Pseudo-nitzschia species in the Magallanes Region, a work led by Dr. Marco Pinto-Torres, a marine biologist at the Center for Dynamic Research of High Latitude Marine Ecosystems (IDEAL) of the Austral University of Chile (UACH) and the Fisheries Development Institute (IFOP).

For 11 years (2006-2017) and through the monitoring program of HABs carried out by IFOP in Patagonia, monthly data was collected and the areas with the greatest representativeness of this genus in the fjord and channel systems of the region were georeferenced, working in nine stations distributed from the Angostura Inglesa sector (south of the Gulf of Penas), to the northern entrance of the Strait of Magellan. In these places, changes in the water column at the level of temperature and salinity were also analyzed.

Previous taxonomic records associated the species P. cf. delicatissima with the generation of domoic acid in the area, detected for the first time in Chile in January 1997. © Marco Pinto Torres.

Thanks to this study, published in the scientific journal Progress in Oceanography, four Pseudo-nitzschia species already described in the region were identified: P. australis, P. fraudulenta, P. pungens and P. cf. delicatissima. In addition, the presence of two new species was confirmed: P. heimii and P. calliantha, which were not described within this territory.

Previous taxonomic records associated the species P. cf. delicatissima with the generation of domoic acid in the area, detected for the first time in Chile in January 1997. During 2017, IFOP researchers recorded high levels of this component in the Madre de Dios Island area, located in the north of the Magallanes Region. This neurotoxin, which causes Amnesic Venom in Mollusks (AVM,) causes memory loss in humans and birds.

“The importance of this work lies in the fact that it allowed us to update this genus at the national level, which is a complex and difficult group to work with. An important expertise was carried out and we were able to count on the analytical capacity and vast taxonomic knowledge to describe the species”, highlighted Dr. Pinto-Torres.

“It is a highly relevant taxonomic record, since a total of six species were detected. We know that some of these organisms produce toxins that can be harmful for consumption, which helps the registration and constant monitoring of HABs in the Magallanes Region”, explained Dr. José Luis Iriarte, researcher at the IDEAL Center and academic at the Institute of Aquaculture, UACh Puerto Montt, who participates in the study.

Over the next few years, the studies will continue with the aim of detecting the presence of this and other possibly harmful organisms in coastal areas of Chilean Patagonia.

Read the study here.