Dynamic response of microbial communities to change

This research will take stock of the types and activities of phytoplankton and other microbes that live in the Northwest Atlantic and the Canadian Arctic Gateway. It will also track changes in the activity and abundance of microbes as climate change accelerates. Historically, the small size and challenges in identifying key players has limited our capacity to understand microbes, but new genetic technologies and sensors open possibilities that did not exist even a decade ago. By better understanding marine microbes, scientists can forecast how they will respond to their changing environment and how those impacts will cascade throughout the whole marine ecosystem.

Project details

Principal Investigator(s):
Julie LaRoche
Principal Investigator:
Project Start Date:
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Research Outcomes

About the research project

About the research

Phytoplankton — plant-like organisms that absorb sunlight and carbon and give off oxygen — form the base of marine food webs that support all fish and marine mammals. They, along with the host of other microbes that influence biogeochemical cycles, are critical to life.  

The impact

This research will enhance our ability to accurately forecast the effects of climate change on oceanic microbial communities and the resulting cascading effects on the  marine ecosystem. It will provide a critical link between changing microbial communities and the marine life that depends on them.  

The research team

The team of researchers on this project comes from Dalhousie University and is led by Julie LaRoche, who holds the Canada Research Chair in Marine Microbial Genomics and Biogeochemistry.

Team members are:

Julie LaRoche, Chris Algar, Rob Beiko, Erin Bertrand

Julie LaRoche
Chris Algar
Rob Beiko
Erin Bertrand

Research Partners

  • Fisheries and Oceans Canada
  • Bedford Institute of Oceanography
  • Northwest Atlantic Fisheries Centre  
  • GEOMAR of Germany  
  • Woods Hole Oceanographic Institution of the United States  
  • The IFREMER Institute of France  
  • Irving Shipbuilding

Discovery Award winner: emerging professional

OFI researcher Erin Bertrand was honoured with a Discovery Award win in 2018, which named her best 'emerging professional' — a reflection of her work in understanding how warming temperatures and other stressors may change the nutrient requirements of phytoplankton which are crucial in the relationship between the ocean and the amount of carbon in the atmosphere.

“I’m truly honored and grateful to be recognized by the Discovery Centre — an organization that does so much to help people in our province experience science," she says. "I’m fortunate to be leading an excellent group of young researchers in my lab and an pleased to accept this recognition for all of us.”

DNA from Tuktoyaktuk to Prince Rupert

Dr. Julie LaRoche participated in Leg 12 of the Canada C3 expedition, studying microbes in order to establish a baseline that will help assess future change in the environment. The scientific journey took her to remote destinations, providing a unique opportunity to observe Arctic marine life and learn about northern coastal communities. Photos and observations collected during the scientific cruise provide an opportunity to learn more about Dr. LaRoche's work ...

Ocean sleuths

For microbiologists, the best way to deduce what’s happening in the ocean is to apply a forensic-style approach. Learn how OFI researcher — Dr. Julie LaRoche — is using DNA to assess ecosystem health. Read the full story ...

Drivers of Regional Bacterial Community Structure and Diversity in the Northwest Atlantic Ocean

The fundamental role of bacteria in global biogeochemical cycles warrants a thorough understanding of the factors controlling bacterial community structure. In this study, the integrated effect of seasonal differences and spatial distribution on bacterial community structure and diversity were investigated at the regional scale. We conducted a comprehensive bacterial survey, with 451 samples of the Scotian Shelf sector of the Northwest Atlantic Ocean during spring and fall of 2014 and 2016, to analyze the effects of physicochemical gradients on bacterial community structure.

Learn more about the study, in Frontiers of Microbiology. Julie LaRoche is a contributing author.

Microbes and Microbial Activity

  • How do microbial interactions shape productivity?
  • How do microbes respond to rising temperatures and increasing nutrient info?

This info graphic explains all!


Changes in colour identifies microbes

To better understand the communities of microbes in the Northwest Atlantic and Canadian Arctic Gateway, researchers measure microbe abundances and their activities in two ways:

  • Directly measured using oceanographic instruments deployed from ships in the Northwest Atlantic and indirectly, using satellite imagery.
  • The second method takes advantage of changes in ocean colour; microbes of certain types — and in big enough quantities — change the colour of the ocean’s surface. Some algal blooms can be seen from space. From the changes in colour, scientists can determine the abundance and types of microbes in the water.