Relationships are Complicated: Microbes and Micronutrients in the Ocean
Phytoplankton, the microscopic organisms that grow in the sunlit surfaces of oceans, produce about half of the oxygen we breathe. They also form the base of food webs that support our fisheries. Just like humans, phytoplankton require a host of micronutrients to grow, such as iron, zinc and vitamins. They can also become malnourished if they are deprived of them.
Whether phytoplankton thrive or starve hinges, in part, on who their neighbors are. They depend on specialized bacteria around them to produce essential micronutrients, like vitamin B12, but they also compete with those same bacteria for other scarce micronutrients, like iron and zinc. In turn, bacteria rely on the carbon that phytoplankton produce to fuel their growth. These complicated relationships have critical consequences for phytoplankton’s ability to grow and produce organic matter, a process known as ocean productivity. That’s where Dr. Erin Bertrand’s research comes in.
As Canada Research Chair in Marine Microbial Proteomics, Bertrand and her research team are studying micronutrients in ocean processes to better understand how they shape interactions between phytoplankton and bacteria. They are using lab and field-based experiments paired with protein measurements made via mass spectrometry (a technique that helps identify the amount and type of chemicals present in a sample) to document and understand micronutrient starvation, demand and exchange in both phytoplankton and bacteria.
Bertrand and her team hope to shed light on the role micronutrients play in key relationships between ocean organisms and how they help control ocean productivity.