Studying biodiversity in the Pacific Ocean off the coast of Chile: the CEODOS project
Chile is a long country stretching over 5000 kms and with more than 100,000 square kilometres of territorial seas it is a true laboratory used to study the effect of climate change and other causes of impact on biodiversity. Particularly, the Chilean ocean is important for gas exchanges, releasing oxygen and sequestering greenhouse gases, and its study can help us quantify carbon absorption for example.
CEODOS is a Chilean project bringing together 8 centres of excellence from multiple disciplines, including marine biology, mathematics, genomics, bioinformatics and data science; to study the physiological state of the marine organisms responsible for the absorption of CO2 and other gases along the coast of Chile.
Just over three years ago, the flagship expedition Mission Microbiomes of the Tara Ocean Foundation was launched, with a first part in the pacific ocean, sampling for the CEODOS project and also testing the protocols to be used later on during the AtlantECO part of the expedition in the Atlantic ocean. Alejandro Maass, from the Centre for mathematical modelling at the University of Chile, is our guest in the AtlantECO podcast episode dedicated to explaining the CEODOS project and the activities which took place when the Tara schooner was there.
The main objective of the expedition there is to understand the relationship between biodiversity and its environment, including plastic pollution, and the impacts that they have on each other when changes occur. This was studied in different regions of the ocean, first in a pristine environment in the fjords of the south of Chile, where there is an important salinity gradient from the effect of glaciers. The second topic was looking at the human impact through production activities, such as fisheries, and the effects on biodiversity. The third being in more northern parts of the country where important upwellings exist which helps us understand the productivity of the ocean. Finally, in the most northern parts of Chile, to study the impact of the Atacama desert on the ocean and its biodiversity.
The Tara schooner in Chile, 1) in front of a glacier, 2) in Puerto Montt and 3) arriving in Punta Arenas. © Tara Ocean Foundation.
While the sequencing of samples is still ongoing a few first observations were already made.
Firstly, the teams observed that the anoxic zone, where there is less oxygen in the water, extends far more than was previously thought. Secondly, unfortunately Microplastics were found almost everywhere, this means that pristine, plastic free regions don’t exist anymore in that area of the Pacific. Finally, they were able to confirm that the ocean off Chile is extremely active in its capacity to absorb greenhouse gases.