Understanding the unseen

The base of the ocean’s food chain is comprised of a network of microscopic marine machines capable of converting greenhouse gasses into life-sustaining oxygen. These microbes, while invisible to the naked eye, are extremely important — not only to life under the ocean, but to life above it, too.

Julie LaRoche is a Dalhousie biology professor and Canada Research Chair in Marine Microbial Genomics and Biogeochemistry. Dr. LaRoche and her team of researchers study microbes, which make up over 98 per cent of the ocean’s biomass. That’s why the LaRoche group, led by lab manager Jennifer Tolman, participated in Ocean Sampling Day (OSD) again this year.

“The idea of Ocean Sampling Day is to take a global synchronized snapshot of microbial life in the ocean,” says Tolman. “All around the world, everyone’s looking at the ocean around the same time and day.”

Dr. Tolman explains that Dalhousie is Canada’s lead sampling site for OSD, a world-wide campaign now in its second year. The Marine Microbial Biodiversity, Bioinformatics, Biotechnology (Micro B3) project out of Europe created OSD last year so researchers and citizen scientists around the globe could help build the world’s largest database of marine microbes. Water samples are collected in the days around summer solstice (June 21).

“The health of the ocean affects everyone,” explains Dr. Tolman. “It’s important to keep them clean for future generations.”

Universal understanding

“To better understand how the ecosystem is changing, we first have to know what’s in it,“ says Ian Luddington, lab technician with the LaRoche research group.

When it comes to understanding microbes, we’ve barely scratched the surface. Yet marine microbial communities are both indicators and drivers of changing ocean conditions. By studying microbes today, researchers are gathering baseline information against which the effects of future ocean changes — warming, acidification, pollution — can be identified.  

Dr. Tolman, Luddington and biology students set sail in Bedford Basin on Monday to collect water samples. Water samples were gathered using Niskin bottles and environmental parameters were analyzed using a bio-optics package (BOP). The Niskins and BOP were lowered to depths of one, five, and 10metres to collect various samples. Now, physical and chemical parameters such as pH, temperature, oxygen and nutrient levels will complement the biological information that will be extracted from analyzing the microbes later.

Seeing the sea

The challenging part of working with microbes is their size; conventional microscopes don’t let researchers see marine microbes in their natural habitat. Knowing the importance of building more scientific knowledge on the oceans, Dal physics researchers Manfred Jericho and Hans Jurgen Kruzer developed a submersible holographic microscope that can watch microbes in action. 4-Deep, a Halifax-based ocean technology company has since commercialized the microscope technology. The company’s lead research scientist John Samson, a Dal physics alum, was on board with the LaRoche group for OSD.

Samson and Luddington deployed the microscope, so those on board could observe the Bedford Basin microbes in real-time, while the rest of the team collected the samples.

Submersible microscope technology is pushing the boundaries of underwater research. Most systems that offer microscopic resolution use a micro pump that brings a narrow chamber of water across the visible plain of the microscope, and can only operate down to about ten metres. However, some of 4Deep’s submersible holographic microscopes can work, in real-time, at depths of up to 6,000 metres.

Supporting citizen scientists

The great part about OSD is that it isn’t just for scientists. Micro B3 has created MyOSD for “citizen scientists” who wanted to contribute to the global effort too. Sampling kits and a smartphone app gave these ocean-curious individuals the ability to collect marine microbes and important environmental data themselves.

Micro B3 and Dalhousie’s Faculty of Science share a commitment to encourage people of all ages to enjoy the wonders of science. This year, the LaRoche group coordinated MyOSD participation with schools, youth groups and individuals in the Atlantic Provinces and British Columbia. The researchers provided each citizen science group with an official sampling kit. Now, Canada can contribute water samples from the Bedford Basin, the Northwest Arm, Duncan’s Cove, Lawrencetown, Lunenburg, Sydney Harbour, the Bras d’Or lakes, Inverness, Pugwash, Pictou, Cornwallis, and the Minas Basin in Nova Scotia; Augustine Cove and Green Park in Prince Edward Island; and Vancouver in British Columbia.

Dalhousie also hosted two citizen scientists during their own voyage. Working with LaRoche’s research group, Chaya Seale and Meaghan Bartlett worked with experts, collected samples, and gained insight into what it’s like to be an ocean researcher and why the ocean is so important.

“I felt like I was a real scientist,” says Seale, a student going into grade 12 at Lockview High School next year. “I’m excited for when the data comes back and we get to learn more about what kind of microbes live in the basin.”

Once data is collected, it’s sent to Micro B3’s academic partners Jacobs University, Germany, and the University of Oxford, U.K, for sequencing. After sequencing, the data is made available for researchers all over the world to use in future studies for years to come.