Human Activities Mark the Deep Ocean
What do rising atmospheric carbon dioxide concentrations, oil spills and plastic pollution have in common? All of them may end up on the seafloor. How they get there and what impact they may have on marine ecosystems are the subject of Dr. Uta Passow’s research.
Oil and plastics float, and are usually thought to accumulate at the sea surface. But the biological carbon pump may transport carbon and these contaminants downward. As Canada Research Chair in Biological Oceanographic Processes, Passow is exploring this process.
The ocean contains tiny organisms (like one-celled algae and other particles) that form “marine snow”—the dust bunnies of the ocean. These particles sink, carrying carbon and contaminants. Once they reach depths greater than 1,000 metres, they are removed from the ocean’s surface and Earth’s atmosphere for hundreds of years. This process is referred to as the “biological carbon pump.”
Since the industrial revolution, 30 per cent of the carbon generated by human activity has been sequestered through this process. Carbon sequestration can mitigate global temperature increases, but it increases ocean acidification—altering marine productivity and ecosystems, affecting fisheries and harming coral reefs.
Given increased drilling in Artic waters, it is important to understand how oil and plastics are distributed in marine ecosystems and evaluate their impact.
Ultimately, research by Passow and her team will help predict ecosystem changes due to anthropogenic impacts and develop measures to mediate the expected changes.