Researchers at the IDEAL Center are working on the first record of Thecadinium kofoidii, a type of benthic dinoflagellate that had not previously been observed in Chile

The marine benthic dinoflagellate, Thecadinium kofoidii.

Daniela Jofré, IDEAL Center. Dinoflagellates are largely marine, unicellular microorganisms of great importance to ocean productivity. They are only perceptible to the human eye using a microscope and may harm or benefit the ecosystems in which they are found. The best-known dinoflagellates are those that produce the so-called “red tides”.

However, globally, these dinoflagellates have been poorly studied and, in Chile, there is no record of benthic (seabed-dwelling) dinoflagellates.

A study being carried out by researchers at the Research Center Dynamics of High Latitude Marine Ecosystems (IDEAL) of the Universidad Austral de Chile revealed a large presence of Thecadinium kofoidii along extensive tracts off the Punta Arenas coastline. This is the first record of this benthic dinoflagellate, which could benefit the marine ecosystems, in Chile.

“The sandy sediments of these coasts are completely covered by this dinoflagellate, forming very abundant populations,” said Ángel Salazar, the IDEAL Center student who found the microorganism in December 2017, while sampling the coasts with the support of Dr. Eduardo Menschel, a marine biologist at the Center.

Ángel Salazar collecting samples in the Strait of Magellan.

“More studies are needed to determine the real importance of this microorganism in the benthic trophic levels of the Magallanes Region. What is certain is that they have shown themselves to be an active source of carbon and energy (food); T. kofoidii is capable of photosynthesis, which helps oxygenate fine sand sediments and could benefit other communities of organisms, such as crustaceans, which require highly oxygenated areas,” said Salazar.

Meanwhile, according to Dr. Humberto González, director of the IDEAL Center and member of the research team, “We are only recently beginning to grasp the high ecological relevance of this study. The elevated abundance of T. kofoidii contributes to several local trophic levels, and the high rates of estimated photosynthesis help keep the sediments highly oxygenated. In summary the preliminary studies of Salazar and Menschel indicate that these benthic dinoflagellates help improve the “ecological health” of the fine sediments in the Magallanes Region.

Although the IDEAL Center study is focused exclusively on T. kofoidii, other varieties of dinoflagellates that could negatively affect marine ecosystems were found during sampling. “This is an invitation to continue studying these organisms, as there is no previous record of them in the country and, therefore, we cannot determine, for example, how climate change has influenced them,” said Salazar.