Water impacts

Oceans

BelugaWhen Manitobans think of the ocean, our minds either travel to the West or East coast. We often forget that Manitoba is a coastal province. Hudson’s Bay is a part of the Arctic Ocean.

On this page, we deal with these issues related to oceans:

Click a topic to jump to that location on this page.

The world’s oceans cover over 70% of the planet’s surface. Although the water is salty and undrinkable, it is difficult to over-estimate the value of this vast mass of water. It helps regulate the global climate and to ensure that a constant flow of vital nutrients is cycled throughout the biosphere (1).

Climate change impacts in the world’s ocean will have far-reaching effects. Marine and coastal ecosystems may collapse, creating a disastrous domino effect of extinction and loss. Marine animals, plants and invertebrates are not the only creatures in danger. People have much to lose if the world’s oceans falter under the added burden of climate change.

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Sea-level rise

Climate warming will lead to the thermal expansion of water and melting of glacial and polar ice, causing a rise in sea level (2). Rising oceans would permanently flood highly populated coastal cities all over the world, and submerge the atoll nations of the Pacific and Indian Oceans. Precious marine wetland habitats such as mangrove forests and coastal wetlands would be lost to the rising waters.

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Disease and toxic algal blooms

In waters already choked with algae fertilized by nitrate and phosphate pollutants, warmth only encourages algal growth. Algae can be a reservoir and amplifier of dangerous diseases such as cholera, a serious threat for countries with poor water and sanitation (3). Off the East Coast of Canada, the deaths of humpback whales and dolphins have been attributed to algae blooms and viruses (4). Some algal blooms, such as red tides, are also toxic to humans.

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Storms, erosion and sediment

An increase in the number and severity of storms and storm surges would have serious consequences for coastal habitats, as well as fishery and aquaculture industries (5). Increased sea levels and storms would interact to erode beaches, damage coral reefs, and overwhelm coastal wetlands and settlements. Higher storm surges would also pull more sediments and pollutants into the water (6), increasing the turbidity and likelihood of algal blooms.

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Ocean circulation

Winds are created by the unequal warming of the earth’s surface. Many climate change scenarios predict that polar regions will experience higher temperatures, reducing the thermal gradient between the poles and the equator (7). Major ocean surface currents generated by the drag of strong wind on water would weaken or even change. Patterns of vertical water movement would also be altered, devastating marine life that depend on the upwelling of nutrient-rich waters and the downwelling of oxygen-rich waters (8).

Since the 1950’s, zooplankton in the California current have decreased by 70% as the sea surface has warmed (9). This may explain the mass starvations of seabirds such as sooty shearwaters and Cassin’s auklets in recent years (10).

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Marine life in jeopardy

The world’s oceans support a dazzling array of life forms, from massive marine mammals to microscopic crustaceans. Climate change is already disrupting marine food chains. In the Antarctic, penguins are starving for lack of krill, tropical coral reefs are bleaching and breaking, Pacific salmon are moving north, and polar bears in Manitoba cannot gain enough weight to raise their cubs. For more information on marine life impacts, visit Wildlife.

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