Thursday, July 28, 2011

Arctic Update 2

looking from Pangurtung towards Cumberland Sound
The Pangurtung fjord is stunning – steep rock slopes with a few stunted flowers and grasses as the only ground cover. Boulders the size of houses look like they've been tossed around by long gone glaciers. Definitely a harsh landscape but, less alien that the endless sea ice in the Beaufort Sea. Arctic poppies and cotton bloom alongside a stunted form of fireweed. A few bursts of yellow from dandelions dot the landscape. On the beach, sparse patches of kelp indicate the high tide line. Small snails and little shrimp appear to be the only life in tide pools littered with tiny clam shells.

Pangurtung is larger than I expected, but still a very small town. It's situated part way along the fjord on a patch of rocky ground between the water and a hill. The town consists of a large group of houses built up off the ground surrounding a runway. Dirt and mud roads link everything together in town, but the roads don't lead to any other communities. In the store, pop costs over $4.00 a can.

On our first evening in Pangurtung (22 July 2011) we set out in a small boat to recover the closest moorings. In place since last summer, these moorings held receivers designed to pick up acoustic tag signals from passing fish and thermistors to measure water temperature – potentially a lot of good data. At out first stop, a gust of wind whisked one of the laminated sheets of acoustic release codes into the air. Fluttering, always just out of reach, the sheet settled onto the water and slowly sank. The sheet floated beneath the surface tantalizing close but, just out of reach of the boat hook. Codes for one acoustic release were lost.

An acoustic release holds on to an anchor (or whatever else you want it to hold on to) until it hears a specific code. When the code is right, the acoustic release lets go allowing a mooring, less the anchor (anchors typically get left behind), to rise to the surface. Because of the lost codes, one mooring stayed on the bottom, so we'll have to go back for it later. The rest of the moorings we recovered.

There is no dock in Pangurtung, so the ship has to remain at anchor. Small boats run back and forth from shore – a pain when moving a lot of heavy gear and we have a lot of gear. The next morning (22 July 2011), we went aboard the ship to organize our gear. Deck and storage space is limited on this vessel, more so than any other ship I've worked on, so, organizing everything turned into a nightmare. All extra gear was offloaded and stored on shore, we just didn't have room to keep anything extra (which means more time will be lost re-loading gear later).

We pulled up the anchor at 4 am on 23 July 2011. I was in my bunk but, not asleep as anchor chains make a lot of noise going in or out. Our destination was the mouth of Cumberland Sound. We built and deployed 12 moorings, each holding a receiver to listen for fish tags (we haven't tagged any fish yet this year). Mooring components were put together on deck with shackles, knots, tie wraps and black electrical tape. A 200lb anchor is attached to a short length of chain, then an acoustic release, followed by a length of rope attached to a float. The float keeps the line off the bottom and provides buoyancy to bring the mooring back to the surface when the anchor is released. Water depths ranged between 900-1200m.

My first CTD cast was done in about 950m of water. There isn't a winch on board that will work with my instrument, so we used 1200m of line and a capstan. This is much more work than the right kind of winch and resulted in a huge pile of line at the end (we've figured out how to deal with all the line now). I doubt I'll get in as many casts as I originally hoped.

24 July 2011, more moorings were deployed and a 1000m+ CTD cast. Then the capstan hydraulics sprung a leak. To fix it we need a single gasket, based on where we are, there is no way to know how long until a gasket will arrive (one is ordered). I downloaded both CTD casts and the data looks good – both show a temperature minimum around 100m before warming up again (slightly). After downloading my data, we stowed all our gear as we are meeting the CGGS Amundsen (an icebreaker that is also a research ship). The plan is to spend 24hrs of trawling for arctic cod back out the mouth of Cumberland Sound. It might get rough.

Later, I'll attempt CTD casts by hand lowering the instrument – not an ideal solution, I really need that gasket!

CGGS Amundsen
25 July 2011, on route to meet the icebreaker, we spotted out first polar bear of the trip on an iceberg. He was curious about us at first but, as we got closer, he jumped into the water and swam away. At this point in my life, I've seen more polar bears in the wild that any other type of bear. The work with the Amundsen doesn't involve me. We've asked them if they have a spare gasket that will work to fix our capstan.

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