Saturday, December 27, 2008
We woke up late (beacuse it was a sea day) and had breakfast. We were back in the open seas, and breakfast was not as full as it had been while in South Georgia. After breakfast, we had a wrap-up meeting about South Georgia, where people could ask quetions that they had thought of during our time there. From the guides, we found out that most if not all of the icebergs we had seen came from Antarctica, and certainly all of the tabular ones did. There is not enough glaciers around, and they aren't near big enough, to produce what we had seen the day before. They probably came from either the Weddell or Ross seas.
We found out that whales were slowly coming back to South Georgia, but their reproduction cycle is very long, so it will take a while. By contrast, fur seals have been able to come back from near extinction very quickly, so quickly that there are far more of them than there ever were prior to sealing and whaling. One thought is that since fur seals and whales feed off of the same thing - krill - the much lower whale population has allowed fur seals more food thatn they ever would have had before. Our chances of seeing whales will increase the closer we get to Antarctica, which is good since our results so far are nil.
The guides told us a little more about the reindeer we saw on our hike from Fortuna Bay to Stromness Bay. They were introduced in the early 1900s by the Norwegian whalers. The whalers were unsure whether they would have enough food, so they brought in the reindeer as a backup food supply. As it turned out, they didn't need the reindeer, but they never took the Reindeer back to Norway. From the original 20 reindeer, there are now 3000. One benefit that these reindeer have had is use as a control in studies on the Scandinavian reindeer. For example, most of the Scandinavian reindeer were affected by Chernobyl, but the South Georgian reindeer were not. From samples, researcher were able to determine how profound the effect of the radiation was.
We also found out that South Georgia is planning a massive attack on rats. They eat the eggs of certain endangered birds (among other issues), but they cannot effectively be eliminated one by one. So they are planning a full scale attack, basing their plan off of what New Zealand did with Campbell Island several years back. This consists of dropping poisoned bait all over the island, most likely from helicopters. The optimal time to do this is in Autumn, when rats are hoarding food for winter.
There is some talk about culling the fur seals as well, but this is a distant second to rats at this point in time. At some point in time, they will run out of food and/or places to breed, so their population will reach equilibrium. Increasing whale population will probably assist with this as well. Fur seals repopulate much faster than whales, though, in that fur seal females are pregnant nearly all of the time. Only a week or two after giving birth, they are receptive again, and their gestation period (including the dormant period) is almost a year.
The King penguin stock is increasing in South Georgia, but the macaroni population is decreasing, and no one quite knows why. Not all colonie are being affected the same, but there currently isn't any understood rhyme or reason. The King penguin rookery we saw at Salisbury Plain had 60,000 breeding pairs, which isn't even the largest on the island. St. Andrews Bay has more, but it is a more difficult landing than Salisbury.
We were told that elephant seals can dive down as far as 6000 feet (not a typo). Some of the elephant seals are tagged with sensors, and reading their data can help us figure out water temperature, salinity, etc. - useful information for climate change. The male elephant seals moult in February/March, at the end of summer, after the females and the young have finished. That is why we saw so few males despite the fact that the females were huddled together moulting. None of the males we saw were very old - their noses were not that pronounced - probably the oldest we saw was 10 years old. On the other end of the spectrum, Anja told us about an old male elephant seal she saw in New Zealand, which was almost 20 meters (66 feet) long.
At 11, we saw a video "South - Shackleton's Glorious Epic Of The Antarctic." It was very good (and reputedly hard to find). Anja got it as a Christmas gift, but unfortunately wasn't feeling well enough to watch it with us.
Just before lunch, we started to get some large swells, and at lunch they became even more pronounced. Water started spilling (Crystal had to change), so they took it away. They didn't serve us soup - apparently didn't want 50 scalding crotches. By the time the spaghetti came, most everyone had taken off. We were told the swells were a "9" - whatever that means. After lunch, there was essentially nothing we could but go to sleep - it was impossible to get anything done. The rest of the day was a lost cause.