Category Archives: Issues in Science

Warm Atlantic Water flowing into the Arctic Ocean

Posted on January 27, 2011 by | 4 comments

In an article on the Montreal Gazette that was posted today, data collected from a German research boat Maria S. Merian shows that the temperature of the Atlantic water that flows into the Arctic Ocean is at an all time high. The temperature of the Atlantic is at its highest in the last 2000 years. The warmer Atlantic water contributes to the “Atlantic meltdown” that have been occurring, which consists of ice retreat and ice melting.

This is a cause for concern as these changes in the ocean currents affects the Earth’s climate. Past historical records show that changes in the North Atlantic Current bring drastic effects on our climate. It resulted in cold and warm periods that had temperatures plummeting in the northern Europe during the Dark Ages and rising again in the medieval times, then dropping a little again during the Ice Ages.

Long term studies of the effects still need to be conducted as there are no other records that could be cross referenced. There are only few records that date back 150 years, so the research team had resorted to using fossils that are temperature sensitive to record the temperature change.

Perhaps the results of the research will bring caution to the human race and ultimately influence changes in our lifestyles.

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Posted in Biological Sciences, Issues in Science, Science in the News

Ocean Acidification Affecting Marine Life

Posted on January 25, 2011 by | 1 comment

As we continue to release anthropogenic carbon into our atmosphere the earth warms.  The ocean however is actually fighting to combat these changes by absorbing some of the heat.  This sounds like an answer to our problems, but there is a catch: the oceans are becoming more acidic.  As carbon dioxide concentrations increase in the seawater, the carbonate concentrations decrease.  Carbonate is a key building block of the shells of many aquatic organisms and the decreased concentration is having negative effects.

Take a minute to check out this video for a quick explanation of how global warming is causing ocean acidification.  YouTube Preview Image

An in depth case study was done on one Arctic mollusc, Limacina helicina, to test the effects of increasingly acidic waters.   The full research paper can be found here, or you can check out the news article for a condensed version here.  These “sea butterflies” or pteropods, were kept in a controlled environment for 5 days to see how well their shells grew under different pH values.  A pH value of 8.09 (which was recorded in the Arctic in 1900) and a pH value of7.78 (the projected value for 2100) were used.  The results were a startling                       28% decrease in linear shell growth for those kept at the acidic pH compared to those kept in the normal ocean pH.

So what does this mean with respect to ocean ecosystems?  Decreased shell growth may not seem immediately fatal to thepteropods an associated ecosystems but the associated decrease in shell density has some larger effects.

Source: antarctica.gov.au - Copyright Russ Hopcroft

In the Arctic pteropods form the base of the food chain and are eaten by many larger organisms. As the oceans become more acidic the pteropods can’t grow or mature as quickly.  They also can’t swim away as quickly from their prey and are eaten more often.  With a diminishing population of pteropods, organisms that rely on them for food will also be at risk.

Pteropods also play an important role in the geochemical cycle, namely transferring carbon to the deep.  However, with decreased shell density pteropods do not sink as well and so they are not transferring carbon.  Without carbon cycling in the ocean the effects of global warming would be much worse.

Source: forum.ntreev.net

These results are not specific to just pteropods; similar studies have been done on other shellfish and corals which found similar results.  Ocean acidification is causing global effects and the scariest part is that most of them are still unknown.  At this point we can only predict how acidic the ocean will get due to global warming and how strongly shellfish and their respective ecosystems will be affected.

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Posted in Biological Sciences, Environment, Issues in Science, Science in the News

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Corals Are Moving North

Posted on January 24, 2011 by | 4 comments

Flickr: Martin-Klein

As the average temperature of the Earth rises due to climate change, the temperature of the oceans rises as well. These drastic rise in ocean temperatures, affect marine organisms of all shapes and sizes. However, the most prominent effects have been observed on corals. Corals, which are home to thousands of marine creatures, are considered to be some of the most fascinating and eye pleasing marine organisms in the oceans. Unfortunately, they are also highly sensitive to environmental changes.

In a recent article published in Science News (which can be found here), coral migration was studied and tracked by a group of scientists off the coasts of Japan. When they compared current results to data collected from different time periods starting in the 1930’s, they found out that various common coral species have retreated northward, and some have even gone as far as temperate waters. Furthermore, the abundance of coral has decreased proportionately with northward migration.

Mila Zinkova/Wikimedia Commons

If this trend were to continue and not be altered, the population of corals in the oceans will continue to decline. This decline is very unfortunate and it shows how deadly climate change can be. Corals are home to thousands of different marine organisms. Hence, the lost of corals, also causes the direct loss of other marine organisms. Ultimately this can lead to an overall reduction in biodiversity. Furthermore, the decline in coral also jeopardizes recreational activities such as scuba diving and snorkeling.

Although this article, provides excellent evidence to support the fact that corals are moving north and their abundance is decreasing. It does not provide us with ways to prevent or slow down this process. Most of us are already aware of the drastic effects climate change has on marine organisms, but very few of us know how to directly prevent such events from occurring. Hopefully we’ll see more media coverage on prevention methods in the future, so that such events can be prevented or subdued in the future.

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Posted in Biological Sciences, Environment, Issues in Science

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