Aquatic Climate Change
Ocean scientist Dr. Charles Hannah takes us on a quick virtual tour across Canada to discuss a few of the ways climate change will impact marine and freshwater ecosystems.
Transcript
Charles Hannah – Physical Oceanographer, Bedford Institute of Oceanography
People are finally starting to understand that climate change is happening. Global sea level is increasing, global temperature is increasing, and the ocean is getting slowly more acidic.
Like all countries, Canada is trying to understand enough about climate change to be able to make sensible decisions about how to deal with the changing climate.
Fisheries and Oceans Canada has a new program on adaptation to climate change. The goal is to gather enough information to understand what is likely to happen, and develop technologies to help Canadians adapt.
We need to start to map how the large scale changes are going to express themselves locally.
Caption: In Nova Scotia, sea level is rising by 20-30 cm per century, in line with the global trend.
We actually monitor sea level both for navigation purposes and as part of the tsunami warning system, and as part of the global sea level observing network.
Caption: Dr Philip MacAulay – Physical Oceanographer, Bedford Institute of Oceanography
One of DFO’s technological contributions is a new tide gauge, which actually uses laser technology to measure the water level, and this allows us to get more accurate measurements and as well, to get the data home in real time so we can make use of it faster. This then contributes to both navigation, and to our understanding of sea level on the regional scale.
Caption: In the Gulf of St Lawrence, major change is occurring due to the decline in winter sea ice.
We actually go out at the end of winter in a helicopter, deploy an instrument and measure the water temperatures down to depths of about 200 metres, and what we’re finding is the last couple of years, that upper layer of the ocean isn’t getting as cold, sometimes it doesn’t even get to freezing, and so we’re getting less sea ice.
These changes extend throughout the water column and they persist throughout the year, so we expect that changes will start to occur in the ecosystem, and it will have impacts on things like lobster, snow crab, and shrimp, and other fisheries resources in the Gulf of St Lawrence.
We also expect that with less sea ice, we will get larger winter waves. With the larger waves and with the coast no longer protected by the sea ice, we expect more coastal erosion, we expect impacts on the coastal infrastructure including the wharves, and thus more maintenance costs and they’ll have to actually be changes in the way the infrastructure along the coast of the Gulf of St Lawrence is maintained and implemented.
In central Canada, there will be significant impact on DFO’s freshwater responsibilities.
Caption: In central Canada and U.S., 37 million people rely on the Great Lakes for their water supply.
Changes in precipitation patterns are expected to result in lower lake levels and this will impact fisheries resources, it will impact people’s ability to get fresh water for human consumption.
As reported by the Intergovernmental Panel on Climate Change in its 2007 report, with very high confidence, they expect water stress across most of North America, and it is expected that there will be substantial changes to the freshwater systems, and that will actually impact the marine environment as well.
Caption: In British Columbia, the anticipated sea level rise will impact Vancouver, Victoria and Prince Rupert.
Of particular interest is the Fraser River Delta, which is part of Greater Vancouver, and so concerned scientists and other stakeholders are studying how they expect climate change and sea level rise to impact the Fraser Delta, in order to adapt to what’s expected.
Caption: In the Arctic, declining sea ice will impact every species in the region.
The changes right now are most obvious in the Arctic. For the Inuit, travel in the summer has become more dangerous as the ice becomes more unpredictable, so people’s lives are at risk.
In the Hudson Bay, there’s been the arrival of killer whales, the new apex predator that will compete with humans at the top of the food chain.
As sea ice declines, there’s more and more people wanting to either move goods through the Arctic, or explore for natural resources. This will increase the demand for things like charts, and weather services, and search-and-rescue services.
One of the recent DFO innovations is to actually install an observatory in the western end of Lancaster Sound that actually brings environmental information from the ocean up to a location on the coast and it actually gets sent by satellite back to Halifax, and this will start to give us real time information on ice conditions, the temperature, and even basic phytoplankton productivity in that part of the Arctic, which can then help to validate climate models and provide operational information about ice that both coast guard and other mariners can use in their operations.
Climate change will have both negative and positive impacts. The negative impacts are relatively easy to identify. There will be impacts on infrastructure, there will be changes in the way the ecosystems are organized.
Positive impacts are harder to identify, but there will be shifts in fisheries productivity, some places will become more productive than they are now, and this will be a positive benefit for people.
The role of DFO science is to try to understand what the changes are going to be, where they’re likely to occur, when they’re likely to occur, so that these changes can be used by DFO policymakers and all Canadians to adapt to a changing climate.
Credits
With thanks to:
- Fisheries and Oceans Canada
- Bedford Institute of Oceanography
- Canadian Coast Guard
- Canadian Hydrographic Service
- Canadian Program Office of International Polar Year
- Centre of Expertise for Aquatic Risk Assessment
- Maurice Lamontagne Institute
- Small Craft Harbours
- Crisp Films
- Digiteyes/Pat Anderson Photography
- Global Calgary – Shaw Media
- iStockphoto
- Journeyman Film Company
- Mike Wetklo Photography
- NASA Scientific Visualization Studio
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