Question Period Note: Climate Change and Ocean Acidification

Climate Change and Ocean Acidification

Canadians know climate change is real; we are witnessing important impacts that are directly affecting Canadians and our coastal communities.

Our department continues to research and study climate change related phenomena such as ocean acidification, low oxygen levels and changing sea ice, and their impacts on our fisheries and aquatic ecosystems.

Understanding our ocean ecosystems in a changing world is now more important than ever for improving management and conservation measures.

• Canada’s marine ecosystems are changing – due to a combination of factors including climate change, natural variability, and other human pressures.
• Oceans surrounding Canada have warmed, become more acidic, and less oxygenated, consistent with observed global ocean changes over the past century. Ocean warming and loss of oxygen will intensify with further emissions of all greenhouse gases, whereas ocean acidification will increase in response to additional carbon dioxide emissions. These changes threaten the health of marine ecosystems.
• Climate change is impacting the oceans, its resources, ecosystems, and its infrastructure in several different ways:
 Higher ocean temperatures reduce dissolved oxygen and affect fisheries distribution, health, and timing of life cycles, such as when lobsters molt;
 Ocean acidification reduces the availability of calcium carbonate, making it more difficult for several marine organisms to grow shells; and,
 Rising sea levels and increased frequency and severity of storm surges damage shorelines and coastal infrastructure, and harm coastal ecosystems.
• Ocean acidification is the term used to describe the long-term change of ocean chemistry as CO2 is absorbed from the atmosphere. Since 1960, roughly one-third of all carbon dioxide emissions from the burning of fossil fuels have ended up in the ocean. To date, the only certain way to slow ocean acidification is by reducing global CO2 emissions.
• Oxygen concentrations have been declining in both open ocean and coastal waters for at least the past 50 years, largely because of human activities that have increased global temperatures and nutrient discharge to coastal waters.
• DFO's annual State of the Ocean reports describe recent status and trend information on Canada's three oceans, including key findings on sea ice loss in the Atlantic and Arctic oceans, increased ocean acidification in all of Canada's oceans and decreasing oxygen levels in the Pacific and Atlantic oceans.

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