What is happening in our oceans?

With the impacts of Global Warming becoming evermore visible in the terrestrial environment, the aquatic environment (freshwater and marine) is also struggling.

Rising global temperatures and increased CO2 concentrations are leading to challenging conditions that many species are struggling to cope with. In some environments, even slight deviations from normal conditions can lead to catastrophic declines in survival rates.

Temperature

As the air temperature of the Earth continues to increase, the oceans act like a huge heat-sink. This buffering has helped slow down rapid rises in temperature, but at what cost to the marine ecosystems?

Increasing CO2

Once again, the Oceans soak up what they can. However when CO2 is absorbed into water the pH is affected, becoming more acidic. This leads to Ocean Acidification. It may only seem like a small change, but to calcifying organisms this can effect the very structures they build to protect themselves.

Pterapod shell dissolved over the course of 45 days in seawater adjusted to an ocean chemistry projected for the year 2100
Author: NOAA Environmental Visualization Laboratory (EVL)

 

But what has this got to do with Antarctica?

Antarctica is an entire continent of extreme and highly specialised habitats, both above and below the surface.

Icefish larvae
Author: Uwe kils

Antarctic notothenioids (Icefish) have adapted to the freezing conditions under (and in) the ice. Antifreeze glycoproteins prevent ice crystals forming within the blood, allowing the fish to survive being frozen within icy waters.

A second adaptation is the loss of heat-shock proteins. These proteins would help reduce cell damage that might be caused by temperature variation. This loss is in response to millions of years or low and stable temperatures.

Another interesting adaptation is the loss of haemoglobin. The low metabolic rates of Icefish have no constant high demand of oxygen, and therefore carry [the oxygen] in solution. This lack of red blood cells causes their blood to be colourless.

 

Information to add

  • Affects of low pH on calcifying organisms
  • pH on survival
  • Conclusion: Adapt or die?

https://www.nationalgeographic.com/environment/oceans/critical-issues-sea-temperature-rise/

http://research.noaa.gov/News/NewsArchive/LatestNews/TabId/684/ArtMID/1768/ArticleID/11572/Ocean-warming-doubles-in-recent-decades.aspx

http://onlinelibrary.wiley.com/doi/10.1029/2010RG000345/full

https://www.giss.nasa.gov/

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