Submitted by Anonymous on Sun, 12/05/2010 - 10:34
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Antarctic Seafloor Ecology

Im mainly asking paul but stacey or any of the divers have any other input, It would be greatly apperciated.

  1. There are 14 dive spots that the divers always go back to specifically. How are these 14 spots significant? Is it because of pollution level? Location?
  2. I have been following Tina's journals on Polar Trek and was wondering the importance of the cages and experiments that Stacy is pulling out of the water currently? I understand that it has something to do with the level of the ocean where animals live and which ones they reproduce but what is the real significance of that? Why has this been a 30 year experiment?
  3. I have noticed that sometimes your guys use huts to cover the hole and dive from, and sometimes you don’t. Why are the huts used occasionally, and what is their function?
  4. Since you began diving, have you discovered any new species? And what is the biggest breakthrough that has been made in your field that you know of?
  5. Have you guys found of why it is that the sea sponges exploded in growth within the past ten years? Or why do you think they did?
  6. Did scuba divers first go under the ice to examine the ecosystem and then found the pollution problem, or did divers go under to see what effects the pollution had had on the ecosystems? And then I just wanted to ask you if there is any information that you could give me about SCUBA from the experience that you have gathered over the years that I probably wont be able to find from articles. Stories? Interesting discoveries?
Sun, 12/05/2010 - 11:25

Tina Sander

> I have been following Tina's journals on Polar Trek and was wondering the importance of the cages and experiments that you are pulling out of the water currently?The form a record of recruitment (what animals are settling out of the water column, an indication of which animals are reproducing at a given time and whether that is changing over time).
> I understand that it has something to do with the level of the ocean where animals live and which ones they reproduce but what is the real significance of that?
If animals are getting more food, they are likely to be more reproductive. The amount of food available depends on environmental conditions, like how thick the ice is and how much light gets through to allow plants to grow, and how many nutrients there are in the water which depends on where the water is coming from. Different animals eat different things, so who is reproducing also tells us which kinds of algae were thriving, which gives us information about the past water chemistry.
> Why has this been a 30 year experiment?
It was not initially designed to last so long! But one reason was that improved diving safety rules meant that Paul could not dive to 180 ft where he started up some of the experiments, as it is dangerous physiologically. He had to wait until technology caught up, and is using the ROV to complete his experiments now.
>
> Since you began diving, have you discovered any new species?
Paul has discovered new species. It is a benthic ctenophore - a jellyfish that has adapted to live attached to the bottom.
> And what is the biggest breakthrough that has been made in your field that you know of?
One amazing thing has been the discovery that there is a cycle of krill dominating the plankton, that switches to salps (a kind of jellyfish) dominating under certain ice conditions, which has implications for whales and other mammals that rely on krill for food. And I think we are on the edge of a breakthrough on the importance of microbes as food resources in Antarctica.
>
> Have you guys found of why it is that the sea sponges exploded in growth within the past ten years? Or why do you think they did?
We don't know for sure why yet, but we will be working on analyzing the data to figure out the cause if we can. One environmental change that correlates well with the ecological pattern is that in 2000 a mega-iceberg broke off the Ross Ice Shelf and partially blocked the mouth of McMurdo Sound. The iceberg changed the water circulation patterns, which may have changed the supply of larvae moving in the sound. We'll keep pursuing that lead!

Wed, 12/08/2010 - 17:31

Anonymous

So why do you choose those 14 dive spots? location, pollution level, visability