A new study has revealed that DNA can help assess the responses of Antarctic marine life to climate change.
The oldest marine DNA in marine sediments from the Antarctic continent was discovered in a study led by the University of Tasmania, in collaboration with the University of Bonn. This could be dated back a million years, showing that DNA can be the way to study the long-term responses of marine life to climate change. This recognition will help assess current and future changes in marine life around Antarctica.
The study appeared in the journal Communications of nature.
Studying Antarctic marine life with ancient sedimentary DNA
Because Antarctica is extremely vulnerable to climate change, it is critical that researchers study the past and present responses of the marine ecosystem and polar marine life to changes in the environment.
A new technique, called ancient sedimentary DNA (sedaDNA) analysis, allows researchers to interpret what kind of marine life once lived in the ocean and when they lived there. When the composition of this has undergone significant changes, it can often be related to climate change. This knowledge can allow researchers to make predictions about how Antarctic marine life will respond to climate change, now and in the future.
Data revealed by the study
A team of researchers used sedaDNA to analyze sediments acquired during the IODP Expedition 382 ‘Iceberg Alley and Subantarctic Ice and Ocean Dynamics’ in 2019. They used it to analyze changes in marine life structures in the Sea of Scotland during the last. millions of years
The team first carried out a thorough contamination check to ensure that the silkDNA signals were authentic. This was confirmed by investigating the characteristic age-related damage patterns in the recovered DNA fragments. One million year old DNA was detected.
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Dr Linda Armbrecht, the lead researcher from the University of Tasmania, Australia, commented: “This comprises by far the oldest authenticated marine silkDNA to date.” Diatoms were discovered as primary producers within the detected organisms, whose DNA was found to be half a million years old.
The analysis revealed that diatoms were abundant during warm climate periods approximately 14,500 years ago, the last climate change in the Scotia Sea food web.
“This is an interesting and important change that is associated with rapid, global sea-level rise and massive ice loss in Antarctica due to natural warming,” added Dr. Michael Weber, second author from the study of the University of Bonn.
The warming is thought to have led to an increase in the productivity of the ocean around Antarctica.
Future uses of the analysis
The study has shown that analyzes of marine silkDNA can stretch back hundreds of thousands of years. This will help study ecosystem-scale changes in marine life and paleoproductivity over many ice age cycles.
Observed periods of natural climate change can illuminate current and future impacts of human-induced climate warming and reveal how the ecosystem might respond to changes.