The Expedition to Cape Horn, Patagonia in Austral Summer 2022

This is an outline by the lead scientist of Behold The Ocean: Ocean Scientist Maximiliano Vergara – or short: Max.

INTRODUCTIONHigh latitude geographical regions, particularly those with large areas covered by ice fields (glaciers), are expected to be among the most affected environments by climate change. These environments are extreme places where life has managed to bloom despite the physically and biochemically challenging circumstances they face. Scientists have noticed that many changes that will affect global ecosystems in the next 50-100 years are already a reality here – so studying these Patagonian environments gives us an idea of future scenarios. One of the most globally spread and harsh consequences of climate change is Ocean Acidification: increasing CO2 gets into the ocean water, changes its chemistry, and decreases the overall pH of the ocean. We are facing the same issue in the Patagonian fjord and channel region due to the fast-increasing melting of glaciers. When ice melts, the surrounding ocean experiences freshening. This means that the increased freshwater (seawater = high pH; freshwater = low pH) lowers the pH of the ocean and affects the marine ecosystem.

THE PLACECape Horn is a biogeographical frontier for many species of plants and animals. Due to its proximity to the three largest oceans (Pacific, Atlantic, and Antarctic) and ocean currents in the world, Cape Horn is a landmark that establishes the end and the start for many different types of living organisms. Between America and Antarctica, there is nothing but cold and angry ocean: the Drake Passage. The Drake Passage is marked and well known to host the northern part of the circumpolar current, which acts as an isolating belt that protects Antarctica from more hot waters. The circumpolar current strongly influences Cape Horn, along with the particularly extreme climatical conditions.

APPROACHOur main instrument will be the CTD.
According to our friend from Wood Hole Oceanographic Institution, a CTD — an acronym for Conductivity, Temperature, and Depth — is the primary tool for determining essential physical properties of seawater. It gives us a precise and comprehensive charting of water temperature, salinity, and density distribution, and variation that helps us understand how the oceans affect life. We will use a modern CTD equipped with an oxygen sensor and a fluorometer to measure chlorophyll-a. Because de-oxygenation is another of the expected and already happening impacts of climate change, measuring oxygen in the water column allows us to have an excellent biological proxy of how the environments work. A Chl-a sensor will allow us to estimate how much phytoplankton is within the water column. Because phytoplankton is the most essential trophic component of the ocean, it will provide important biological information to link it to other physical and meteorological info.