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The right tools

Memorial researchers deploy underwater gliders to gauge ocean health


By Jeff Green

Scientists are immersing themselves into new studies aimed at understanding oxygen dynamics in the Gulf of St. Lawrence.

The northern region of the gulf is an important ecosystem in the harsh North Atlantic.

In September, a team deployed one of Memorial’s eight underwater gliders off the west coast of the island.

The glider — an autonomous underwater vehicle — is currently collecting data between Rocky Harbour, N.L., and La Romaine, Que. It will be retrieved near the end of November before ice forms for the winter.

The goal of the project is to figure out why the ocean, particularly coastal and inland seas, are losing oxygen.

‘Part of the puzzle’

Oxygen is a vital variable of ocean health, says Nicolai von Oppeln-Bronikowski, glider operations manager at Memorial.

When there is less oxygen in the ocean, species that “breathe” underwater feel those effects as stressors, he says.

“Cod, and many other fish, avoid water that falls below certain thresholds in oxygen saturation. Declining oxygen levels are only part of the changes observed in the gulf together with warming temperatures, increasing salinity and rising carbon dioxide that lead to ocean acidification. Measuring the changes, or decline, of oxygen is just one part of the puzzle. So, too, is knowing the reasons for why this happens.”

A Memorial alumnus, Mr. von Oppeln-Bronikowski (B.Eng.’17, M.Sc.’19), says the deep waters in the Gulf of St. Lawrence have seen a 30–40 per cent decrease in oxygen concentrations in the last 80 years.

“We all have to adapt to the changes that are occurring everywhere, including the ocean.” — Nicolai von Oppeln-Bronikowski

Although scientists have been monitoring the situation for some time, they still have questions and want to observe how that part of the ocean is affected by seasonal changes.

Team approach

He says using Memorial’s gliders as part of the research has multiple advantages.

Gliders are relatively cheap; they cost a tiny fraction of a ship cruise. They provide high-resolution data in real time and, in the case of the gulf, offer data for the full water depth.

Teams can also choose where to collect the data and how long to keep the gliders at sea.

“This makes gliders a good platform to observe the spatial patterns and changes of oxygen in the gulf over the next few months,” said Mr. von Oppeln-Bronikowski, who credits the entire glider technical team for playing an important role in the research.

Citizen science

A big part of that research is also connecting with local communities.

A yellow glider floats in the ocean.
A glider in Trinity Bay as part of field work to test new carbon dioxide sensors for a mobile ocean carbon observatory in conjunction with the VITALS project.
Photo: Submitted

This summer, Mr. von Oppeln-Bronikowski and Dr. Brad de Young (B.Sc.’77, M.Sc.’83), Honorary Research Professor, Department of Physics and Physical Oceanography, Faculty of Science, travelled to Griquet and Quirpon on the Great Northern Peninsula.

They met with people involved with the fishery who will help deploy another glider along the northern tip of the island this month.

“The Labrador Sea is one of the key turning points in the global climate system.” — Dr. Brad de Young

As part of that project, the glider will collect bio-geo-chemical data from the Labrador Sea.

The plan is to keep the glider deployed for six months before recovering it next year near Heart’s Content on the Avalon Peninsula.

‘Turning points’

“The broader goal of this work is to see what is happening in the Northwest Atlantic, in particular during the winter time in the Labrador Sea,” explained Dr. de Young.

“The Labrador Sea is one of the key turning points in the global climate system.”

An underwater view of a yellow glider. The water has a green murky colour.
The glider “Sunfish” being tested for the upcoming Labrador Sea HOTSeALS project.
Photo: Submitted

Conditions in the Labrador Sea can be extreme: winds above 100 kilometres per hour, temperatures below -30 C and waves that are more than 10 metres in height.

It’s a challenging environment for ships, so gliders are important for the work.

“The extreme conditions of the Labrador Sea led to the formation of “deep” water that moves through the global ocean, carrying oxygen and carbon dioxide that has been taken from the atmosphere,” Dr. de Young told the Gazette.

Dr. Brad de Young stands in front a yellow glider.
Dr. Brad de Young
Photo: Submitted

“Better understanding of what is happening in the deep ocean also has implications for local fisheries, for coastal communities and indeed for all of us. The climate around us is changing and it would be helpful to understand how. We live in a time of global change and, while there are many possible things that could happen, the details of what is to come are uncertain.”

Next steps

For his part, Mr. von Oppeln-Bronikowski says sophisticated equipment such as gliders are providing researchers and community members with more insight and data about changes taking place in the ocean.

“We all have to adapt to the changes that are occurring everywhere, including the ocean,” he said.

“By having more accessible data, we are better able to detect changes and make decisions on a global scale. Right now we don’t have all the answers, but without the right tools we can’t tackle the next steps.”

Those interested in learning more about Memorial’s gliders, including its scientific application in various settings such as the Gulf of St. Lawrence and the Labrador Sea, and the gliders team can visit here.

These projects are supported by a number of partners, including the Ocean Frontier Institute, MEOPAR and many others. The OFI was established in September 2016 through a partnership led by Dalhousie University, Memorial and the University of Prince Edward Island. 

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