Dear friend of CIFAR,

Greetings from the dead zone – “oxygen minimum zones” actually. Off the coasts of Chile, Namibia, British Columbia, Oregon, and elsewhere there exist expanses of ocean that are virtually gasping for air. We think of our oceans as abounding with life of every shape and size, from jellyfish to blue whales. But I have spent the last four years researching areas of the deep that are inhospitable to multicellular life. Many mysteries surround these zones, but one of the most alarming is that they are expanding and intensifying.

On one level, the seeming lifelessness of these zones is clear: there is little to no oxygen for energy production. Oxygen is fundamental to existence as we know it – at least with respect to life forms that we can see without a microscope. However, the vast majority of life on Earth is microscopic – it exists in the form of diverse microbial communities. What’s so fascinating about oxygen minimum zones is that they support a microbial community adapted to thrive in the absence of oxygen. The combined metabolic activity of this community in turn has a profound influence on marine nutrient and greenhouse gas cycling on a global scale.

My laboratory is trying to understand how the microbes living in oxygen minimum zones manage to survive – and thrive. By studying the genetic sequences of the entire microbial community, we have identified a number of interesting metabolic innovations, including the capacity to use sulfur-based and nitrogen-based compounds to derive energy.

Our observations raise many fundamental questions: What is the ecological role of oxygen minimum zone microbes with respect to sulfur and nitrogen cycling? Why are these zones expanding? What does expansion mean for global warming, and for the health of the oceans and our planet? And what does the existence of such a diverse and specialized microbial community say about the power of life to adapt to environmental change?

These are the questions that I am trying to answer as part of my contribution to CIFAR’s Integrated Microbial Biodiversity program. Together, we are rediscovering the world one microbe at a time…

Best wishes from the frontiers of human knowledge.

Steve Hallam

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