Peter Chandler, Physical Oceanographer, Fisheries and Oceans Canada: We have about 80 stations in the Strait of Georgia and Juan de Fuca and it takes us about a week to sample all of them. One of the reasons that we undertake this survey, is that we're interested in understanding the oceanography of the region, and by monitoring the ocean we can identify changes that are occurring, which may be indicators of the ecosystem being at risk.
Marie Robert, Physical Oceanographer, Fisheries and Oceans Canada: Line P is a series of set locations along a 1,500 kilometre line that stretches west from Vancouver Island. We sail Line P three times per year. The data we collect are used to study ocean climate, to learn about ocean circulation and currents, about the biology in the area, and much more.
Peter Chandler: The primary instrument that we use is a rosette, which we lower from the stern of the ship. So, as we lower it off the ship and it descends from the surface to the sea floor, the electronic sensors are gathering data on temperature and salinity and fluorescence, all the way down. When it gets to the bottom and we start to raise it, we'll stop.
Peter Chandler: All right, bring her up to 1-5-0.
Peter Chandler: We'll stay at certain depths of interest, we will snap a bottle that will trap water at that depth and we'll do that at several depths on the way to the surface.
Technician: (off-screen) Surface!
Coast Guard Hoist Operator: (off-screen) Rosette at the surface.
Peter Chandler: Then, when we get the rosette back on board, we take the water and we sample it into smaller containers, with specific analysis to go to each one. Some of it is for physical properties like the oxygen, others are chemical properties, like the nutrients, others are biological properties, like the chlorophyll.
Marie Robert: More than fifty years of ocean data reveals trends. We've observed gradual ocean warming along Line P, as well as lower oxygen levels in the deep waters along the line.
Peter Chandler: To give us an idea of what's living in the ocean, at a microscopic level, we use nets that we tow vertically from the bottom to the surface. Each year, there's a spring bloom when the plankton take up the nutrients and there's tremendous growth. And, this is important for the juvenile salmon as they migrate from the rivers through the strait to the ocean because if they can hit the strait when that food supply is abundant, they become healthier before they go into the ocean and that will inform us in years to come when they return to spawn what the fisheries quota might be. And so, with this combination of physical, chemical and biological properties, we hope to build the picture of what are the main processes that are at play in the ocean. We can use this information to develop and validate computer models that try and give us even more information on how the conditions are changing.
Marie Robert: In addition to ship sampling, ocean scientists also have the benefit of Argo, an international system of more than three thousand sampling floats.
Robin Brown, Manager Ocean Sciences Division, Institute of Ocean Sciences, Fisheries and Oceans Canada: The Argo program is now entering its maturity phase and the data from Argo will be combined with observations from ships and observations from satellites to create a new array of oceanographic information products for use by mariners, industries, government and the public.
Marie Robert: In the past ten years, the Argo system has helped scientists to understand that the Earth’s oceans are now absorbing a higher proportion of heat from global warming and while this impacts the oceans, it is slowing the warming we observe in the atmosphere.
Robin Brown: So now, oceanographers can do what meteorologists have been doing for many decades: track for the first time the movement of water and ocean properties in the global ocean, without having to use extremely expensive research vessels and being able to go in places and work in weather that would be inaccessible for those ships.
Learn more about ocean science and monitoring.
With thanks to:
- Institute of Ocean Sciences
- Canadian Coast Guard
- Canadian Operational Network of Coupled Environmental Prediction Systems
- KÖBB Media
- Argo footage is courtesy of The Argo Project Office
The following images and footage are courtesy of NASA’s Earth Observatory and NASA/Goddard Space Flight Center Scientific Visualization Studio:
- Flat Map Ocean Current Flows with Sea Surface Temperatures (SST) (2:40)
- The Big Muddy, Western Edition (3:04)
- Phytoplankton off Vancouver Island (3:07)
- Aquarius Ocean Circulation (4:14)
- Perpetual Ocean (4:46)
- Aquarius Sea Surface Salinity 2011-2014 – Rotating Globes (4:49)