05 November 2000 - Bird Island Relief At Last
RRS James Clark Ross: Diary entry, 5 November 2000
Noon Position : 59 degrees 58 ' South. 45 degrees 53 ' West.
Distance travelled since Grimbsy: 8782 nautical miles
Air temperature @ noon: 1.6 degrees Celsius
Sea temperature @ noon: 0.0 degrees Celsius
BIRD ISLAND RELIEF AT LAST
It's been a busy but successful week. The two-day science programme was completed despite tricky conditions, and the weather window for the Bird Island relief at last appeared, although again conditions were not perfect and certainly very changeable.
Wednesday saw a start to the moving of 75 tonnes of cargo. The cargo had to be located, moved from the ship to the cargo tender, which then made its way into the small bay where the station is sited. It then had to be unloaded onto the end of a very small jetty and man-hauled down to its allocated spot.
It's a slow and laborious process, and requires plenty of patience and muscle power. Good planning meant we still had the personnel for Signy station on board with their few extra hands to spread the load, although, despite this, I think most people found a few aching muscles they hadn't felt before. Just to make the process a little more exciting the whole thing is watched by the resident fur seals, who will take any opportunity to get a little bite in! All in all it's a tough job and reminiscent of "ants at work". Thursday and Friday saw early morning starts at 0400, and everything was completed by sunset on Friday.
Friday turned out to be a stunning day on Bird Island, apparently quite a rarity, and it was possible for some people to get out to take a look at what the island offers. Bird Island lies 0.4 km off the western end of South Georgia and is the main centre for BAS bird and seal studies.
A potted history: The first permanent hut at Bird Island was installed in 1958 by the Falkland Islands Government. In 1963 the United States Antarctic Research Programme added a further two huts. BAS has supported summer work at the station since 1971, and this changed to a year-round occupancy in 1983, with an overwintering complement of three or four.
The island, especially noted for its fur seal, penguin and albatross populations, is a designated Site of Special Scientific Interest. Station personnel kindly guided us up to one of the wandering albatross nesting sites, and Andy Wood has written a few lines below on these birds.
Wandering albatross chick happy on nest
Chick a bit miffed
Still sitting around on their nests are the chicks of the wandering albatross. They have been there all winter being fed every week or two by the parent birds. Satellite tracking studies of the adult birds have shown that they can be off foraging for squid on the Patagonian Shelf, anywhere from south of the Falkland Islands up to Rio. That's a round trip of at least 4000 km, just to feed that chick back on Bird Island. Unfortunately the populations of wandering albatross have been in steady decline in the past twenty years or so, and recoveries of ringed Bird Island birds have shown that it is longline fishing in their foraging areas which is the major factor in this decline. Next time you go to the supermarket and buy that tin of Tuna which says "Dolphin friendly - caught on longlines", ask yourself is this also albatross friendly?
SCIENCE by Mark Belchier
Every year British Antarctic Survey scientists undertake a survey to estimate the biomass of Antarctic krill (Euphausia superba) in the waters around South Georgia. This survey usually takes place in the middle of the austral summer (December - January). Since 1996 the survey has been conducted within two well defined 80 x 100 km areas or 'boxes' which span the continental shelf-break to the north-east and north-west of South Georgia. Acoustic surveys which use sensitive echo-sounders are the favoured means for assessing krill abundance, as they allow detailed sampling of large areas over a short period of time. BAS scientists currently use the a SIMRAD EK500 scientific echo-sounder to conduct acoustic surveys of krill.
The echo-sounder showing a swarm of krill
EK500 echo sounder control unit
During the last week, when the rough weather moderated sufficiently, an acoustic survey was undertaken along four predetermined transects of the 'western box' area to the north-west of South Georgia. Data from this 'early season' survey, which covers a region that will be surveyed again in December - January, will provide ameasure of the seasonal changes in krill abundance around South Georgia. In addition to the acoustic survey, CTD deployments, measuring salinity and temperature, were made at four stations within the survey area. Nets are usually deployed to fish for krill during a survey to provide information on the characteristics of the krill which are observed on the echo-sounder. Unfortunately, bad weather prevented the use of the net (F-Net) over the last week, but it is hoped that these data can be obtained from the current studies on krill in the diet of predators at Bird Island.
MEN OF THE WEEK: The Cargo Tender Team - For their hard work in loading, unloading, loading, unloading etc. the tender for three days with weather and sea conditions outside the cove not captured in the photo!