Figure 1: From Left to Right: Rodrigo Sanchez, Christoph Mayr, Lilian Reiss, Gunter Försterra, Aris Thomasberger, Luis Hernández Maldonado.

In January 2018 a team of six brave scientists from the Huinay Scientific Field Station embarked an adventurous expedition into the heart of the archipelago Madre de Dios (Mother of Gods Archipelago) situated in the province of Última Esperanza (Province of Last Hope) of the Region Magallanes and Chilean Antarctica.

The expedition group consisted of two teams, a terrestrial and a marine one, plus Huinay’s fearless captain Don Boris. The terrestrial team’s (Christoph and Lilian) mission was to collect calcareous sinter, a freshwater calcium carbonate deposit with well-developed lamination, as well as core samples of old trees in order to reconstruct the climate history of the area through stable isotope analysis.

The marine team`s (Fossi, Rodrigo and Aris) mission was to visit an experiment site in the narrow Copihue Channel (50°20’24.23″S, 75°22’42.51″W) were a recent mass mortality of the hydrocoral Errina antarctica is being investigated. After monitoring equipment installed on a prior Huinay expedition was reported missing, the team brought a full new set of instruments including multiple temperature logger, a conductivity meter, two current meter and one acoustic doppler current profiler that needed to be installed in the Channel.

After a 24 hours boat trip from Puerto Natales through the channels of the Magellanes Region, the group arrived at their destination and basecamp – the world’s southernmost limestone mine on the very isolated Guarello Island where accommodation, food and workspace was provided by IMOPAC, the mine operator.

Figure 2: World’s southernmost limestone mine on Guarello Island.

Shortly after arrival, the marine team started to unpack the expedition boxes and dive gear while the terrestrial team already started to explore the surrounding forests.

During the following ten days, ten dives were conducted in occasionally difficult conditions due to very strong and rapidly changing wind driven currents. The monitoring instruments were successfully deployed and pictures were taken of recruitment tiles installed in 2016. To the delight of the divers, multiple new recruits of the hydrocoral E.antarctica were spotted along the channel’s walls, some measuring about 25cm in diameter, after a mass mortality event eradicated the entire population some years ago.

Figure 3: Diver installing a current meter.

In September 2018 divers will head back to this remote area to retrieve the instruments and read out the data, revealing some more secrets of this incredibly interesting and unknown world and hopefully giving hints to what could have led to the sudden death of hydrocorals in the narrow channel.

Figure 5: New recruits of E.antarctica in the Copihue Channel.