Ice Stories: Dispatches From Polar Scientists » petrals http://icestories.exploratorium.edu/dispatches Mon, 15 Nov 2010 20:40:36 +0000 http://wordpress.org/?v=2.9.2 en hourly 1 The Scene Outside: Lots of birds http://icestories.exploratorium.edu/dispatches/the-scene-outside-lots-of-birds/ http://icestories.exploratorium.edu/dispatches/the-scene-outside-lots-of-birds/#comments Thu, 11 Feb 2010 01:06:29 +0000 Rob Dunbar http://icestories.exploratorium.edu/dispatches/?p=2228 JOIDES RESOLUTION, OFF THE COAST OF WILKES LAND, ANTARCTICA– Our ship is constantly surrounded by Albatrosses, Petrels, and Skuas. Sometimes we see more than 100 birds surrounding the ship. They swoop and dive, looking for food in the water...]]> Temperature 0°C, wind 30 kts, 6 meter swells

At Site U1359, Hole U1359B,
Position: 64º 54.25’S, 143º 57.63’E
Water Depth: 3100 meters

ABOARD THE JOIDES RESOLUTION, OFF THE COAST OF WILKES LAND, ANTARCTICA– Hi everyone! As we approach our 2000th meter of drilling I thought I would change things up a bit with this blog and send along some photos of the birds we’ve been seeing. The Southern Ocean is the coldest and windiest on Earth, but it also one of the most bountiful. During the 3 or 4 months of long days and short nights, the “farm” operates 24/7. The plants that live in the sunlit waters here are nourished by nutrients that mix upwards from the deep sea and go into overdrive building their cells. It’s easier for nutrients to mix upwards into the sunlit upper waters here simply because the water column is “isothermal”. This means that we see very little variation in the temperature of the sea between the surface and the bottom waters over 3000 meters below us. It is all close to 0 degrees Celsius. This means that it takes very little energy to move dense cold water from the deep upwards because the surface water is also cold and is almost as dense. So the plants have everything they need. The wind and circulation drive the mixing, which brings in the nutrients, and the sun keeps the farm growing nearly 24 hours every day. Plants (mostly single-celled protists called diatoms) grow fast and the small plankton that eat the diatoms grow fast as well. Which brings us to the birds…..


Albatrosses in a storm.

Our ship is constantly surrounded by Albatrosses, Petrels, and Skuas. Sometimes we see more than 100 birds surrounding the ship. They swoop and dive, looking for food in the water, either plankton or small fish, or perhaps they think we are land. We haven’t seen one try to rest on the ship yet. In fact the Albatrosses rarely set down at any time. They fly 1000’s of miles from their breeding colonies and are at sea for months and even years at a time.

Here are some photos of the seabirds we’ve seen so far.

These first two are of Black-browed Albatrosses (Thalassarche melanophrys). They live throughout the Southern Ocean and breed in places like the Falkland Islands and South Georgia. They can live to be as old as 70 years and spend long periods of time at sea, even encircling the globe. They feed on krill and small fish – that in turn eat diatoms and smaller plankton.


Black Browed Albatross

Black Browed Albatross

The most common bird we saw at our drill sites close to the Antarctic continent were the Pintados, also known as Cape Petrels (Daption capense capense). The name Pintado comes from the Spanish word for “painted”. They live throughout the Southern Ocean, mainly eating krill, especially on and near the continental shelf of Antarctica in summer. A 2009 census estimates there are over 2 million Cape Petrels alive today.


Cape Petrel (Pintado)

Cape Petrel (Pintado)

Cape Petrel (Pintado)

We’ve also been surrounded the past few days by Southern Giant Petrels (Macronectes giganteus). These are indeed big birds….females can weigh up to 18 pounds. Sometimes they are called “stinkers” as they can spit a foul-smelling liquid at predators or when they are perturbed.


Southern Giant Petrel

Southern Giant Petrel

I hope you enjoy these photos! I’ll get back to our science and progress next time and I’ll try to knock out least one more video blog. We are VERY busy with work here now but it all very exciting.

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