Today CUBE attended a talk about the Antarctica. The talk was conducted by Professor Lloyd Peck, from the British Antarctic Survey, so obviously you know that you are in good hands. Not much can be found in the internet,but as far as CUBE knows, Peck isa graduate from Cambridge, and got his PhD in Portsmouth, having been working with BAS for almost 26 years now, all positive indications of a talk not to be missed.So CUBE was there, on time, sitting in the firsts rows, pen and paper in hand, determined not to miss a single thing. Pecks talking speed was hard to follow at times, but as there was an awful lot to be covered a vast amount of information was gathered.
The talk was centered on the adaptations of Antarctic marine animals and the impacts of climate change on this ecosystem and started off by making a general overview of the amount of biodiversity present in that area.
Contrary to popular belief, it turns out that besides penguins, seals, and whales, there are more than 4000 species described which is more than the Arctic. Moreover, the Antarctic sea bed has a greater diversity of phyla than the tropical coral reefs. This is an impressive fact, that perhaps not a lot of people are aware
of, mainly due to the lack of publicity on this particularecosystem.
But Peck goes into more detail. For instance, apparently the Pycnogonids, or sea spiders, are two times more diverse in this polar region than in any other place on Earth, having 20% of the species.
This extreme marine environment have rather stable temperature, being the most thermally stable environments. These close to 25 million years of stability has allowed fine adaptations to evolve which are not found anywhere else in the planet.
However, the Antarctic also suffers huge seasonal variabilities, particularly ice extent. Ice coverage varies dramatically through the year, gaining and loosing 10 to 15 km sq of sea ice. This area is roughly twice the size of Australia and forms and disappears every year, a very astonishing fact indeed.
Ice bumping in the sea bed causes the polar regions to be one of the most disturbed
environments in the planet, thus one begins to wonder how animals found ways to survive such hostile environment.Well, for one thing, the stable annual range of only 2-3ºC helps.
But before going into the unique adaptations, another key facts about diversity in the Antarctica.
There is greater variety of phytoplankton in the polar regions, with the seasonal bloom in spring being one of the most intensive blooms in the planet, so intense that divers can hardly see their hands! This of course occurs near shore, which are the most "productive" areas in the polar regions.
Another important characteristic is the slow development rates found in most polar animals. It seems that development rates are 10 times longer in the Antarctic sea bed than anywhere else on Earth, which is greatly due to the stable temperatures found.
Also, Peck continues, oxygen consumption in bivalve molluscs is also lowest and the activity rates of many animals is 2 to 5 times slower than in other environments, that is, for instance burrowing the sand or a shell for shelther or feeding may take 28 days instead of 2-5 days.
to be continued tomorrow: Some unique adaptations
CUBE
reporting from the University of Birmingham, UK
17/02/2011
interesting to read: http://www.earthwatch.org/europe/newsroom/news_events/news-5-publicvote.html
No comments:
Post a Comment