MEDS: A World-Wide Window for Ocean Data

The waters of the world meet at the computers of the Marine Environmental Data Service (MEDS) in Ottawa. This small unit of the Department of Fisheries and Oceans (DFO), with only 18 people, gathers, manages, and disseminates a great treasury of oceanographic information for Canada and the world.

For centuries, the main form of marine data was the nautical chart, showing bottom depths, coastlines, and rocks and shoals. In the 1870’s, the British vessel Challenger collected temperature, salinity, current, biological, geological, and other data during a round-the-world voyage, laying the foundation for modern oceanography. Since then, information has piled up at an ever-increasing rate, creating a need for data-masters of the sea.

In 1974, MEDS merged ocean-data activities previously done by several agencies, including the Canadian Hydrographic Service (CHS), which produces hundreds of navigational charts for Canada’s waters. MEDS took responsibility for data on what scientists call the “water column,” above the bottom. Today, climate-change scientists seeking records from decades back, oil-exploration or construction companies seeking up-to-date information on water heights or wave behaviour, biologists investigating the oceanic factors influencing fish, and many others depend on the science and computer experts at MEDS.

Why Canadians need MEDS?
For mariners in such areas as the Bay of Fundy, home of the world’s highest tides, CHS tidebooks are the Bible. MEDS supports CHS in archiving tide and water level data, combining records reaching back more than a century with real-time observations from Canada’s system of tidal gauges.

Wave heights and patterns form another crucial bank of information, for scientists, oil-platform designers, safety engineers, and others concerned with the driving force of the sea. Wave data are available from more than 400 locations on Canada’s coasts and the Great Lakes – St. Lawrence system.

Who provides the raw data for MEDS?
DFO’s research centres and vessels produce a part, but MEDS’s specialists tap into many other data banks in Canada and abroad, governmental and military, academic, and private-sector, such as “volunteer vessels” making oceanographic measurements.


This map from DFO’s on-line GeoBrowser shows data acquired by MEDS in the last 30 days. The spots on the map are red for surface drifters, purple for other kinds of measurements, e.g. waves, tides, Argo, ships.

“We also do data archaeology, digging up old sources,” says Robert (Bob) Keeley, Acting Director of MEDS. “We recently acquired a useful set of data from the 1930’s, written on recipe cards. Our oldest records go back to the Challenger expedition and even earlier. We have water-level records from the Arctic in the 1840’s.

“Information storage has gone from paper to punch cards to magnetic-tape reels to computer disks and DVD’s. We keep up with it, and we write our own software for handling most data.”

Besides organizing the wealth of information, MEDS staff ensures its quality. Inaccuracies can creep in, for example, when data are incorrectly processed. Special computer programs search out anomalies, aided by the experience and intuition of MEDS personnel.

MEDS and Oceanographic Profiles
MEDS is not only Canada’s but the world’s repository for some data sets, including oceanographic profiles. These include such variables as temperature, salinity, and oxygen, graphed against depth, distance, or other parameters. Profiles are highly useful in unlocking secrets of the sea and atmosphere, and researchers keep adding to them. MEDS receives more than 300,000 new profiles yearly.

Profile of oxygen presence in Bonne Bay, Newfoundland, varying with depth and distance from shore. (Courtesy MEDS)

“It used to be that scientists would labour on their next paper for months or even years, and guard their data until it was done,” Bob Keeley says. “Now, more and more, they see the advantage of prompt sharing. It helps both research and operational oceanography, which provides recent or real-time data to governments and enterprises.”

A spectacular example of real-time data sharing is the international Argo project, in which more than 20 nations, including Canada, are deploying 3,000 buoys around the world. These sink, drift, and resurface to send in temperature and salinity profiles by satellite. Argo when fully deployed will produce 10,000 profiles a month, available on-line within 24 hours to scientists and citizens everywhere.

As for oceanographic profiles, so for surface drifting buoys: MEDS is the world repository, holding almost 34 million records.
“It’s not that we had greater resources than other countries,” Bob Keeley says. “But Canada took an early interest in international-data management, we volunteered expertise, and we ended up as a focal point.”

Within Canada, MEDS also stores information from tens of thousands of water samples, both marine and freshwater. Data sets record the presence of contaminants such as PCB’s and furans. A related program, the recent BioChem initiative, is improving access to plankton records and other biological and chemical data, reaching back to the 1920’s.

MEDS has also begun managing data on invasive species and their spread. Other collections include offshore oil and gas environmental information, aquaculture data, daily seawater reports from lighthouses, and more.

Information flows out partly through individual requests from researchers in Canada and around the world. “They could want records off their dock,” Bob Keeley says, “or for the whole North Pacific.” As well, huge batches of data feed out through regularly scheduled emissions, weekly or daily.

MEDS and its international network
Meteorologists and oceanographers are major users of marine data, under arrangements overseen by JCOMM, a joint commission of the World Meteorological Organization and the International Oceanographic Commission. JCOMM draws on experts from many countries, to co-ordinate, among other things, the management of data from thousands of volunteer vessels, data buoys, and other sources.

MEDS plays an active part in JCOMM and in many other international data networks. With limited resources but far-sighted attitudes, the small unit has earned a large place in the world of oceanographic data management.
(For further information: see http://www.meds-sdmm.dfo-mpo.gc.ca/.)

Last updated : 2005-09-12

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