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Descartes prize

18. July

Can you spot the crinoid?

Look at the size of those antennae!

Todays Highlights

Date:July 18, 2004
Author:  Nicola King (Oceanlab, University of Aberdeen), Lars Stemman (Université Pierre et Marie Curie, France)

The ROV crew worked tirelessly through the night, and finally discovered a small leak in one of the pressure cans.   They corrected the elusive problem and we had a pelagic dive to 1000m early this morning; Several deep pelagic organisms were captured by the ROV suction system.  Both jellyfish (tentatively identified as Aegina grimaldii) and sea gooseberries (ctenophores, Beroe abyssicala) were brought to the surface in special housings onboard the ROV.  After delicate removal from the system, specimens were recorded in all their splendour within a special vessel that enables pelagic organisms to move without being affected by the sides of a tank.  Throughout the day the respiration of these organisms has been recorded by measuring the amount of oxygen they use in a given amount of time.  The organisms are very sensitive and have to be kept within a temperature-controlled environment whilst this research is being carried out.

The ROBIO lander also completed its 10th and deepest deployment to 3508m, returning with images depicting the typical environment of the Mid-Atlantic ridge; tumbling basaltic pillow lava with patches of soft sediment.  A variety of invertebrates (animals without backbones) were recorded in the images, including a deep-water coral, squat lobsters and a deep-sea crinoid.  Crinoids are organisms that are generally only found in the deep-sea and are also known as "sea lilies" because of their characteristic flower shape.  They resemble a starfish on a stalk and live attached to the bottom filtering their food from the surrounding water.  The dominant fish visiting the bait throughout the deployment were the abyssal grenadier, Coryphaenoides armatus, and Barathrites iris; a fish so rare that it doesn’t have a common name!

Marine snow is the rain of biological particles to the seafloor from the surface layers of the ocean.  Resources are low in the deep-sea and therefore marine snow is the main food input enabling organisms to survive in the depths of the ocean.  Scientists on board have been looking at particles within the water column using a piece of equipment called an Underwater Video Profiler (UVP).  The UVP records and analyses images of particles from the surface to 1000m.  Using the UVP it is possible to count, measure and identify different particles and planktonic animals.  This data can then be used to compile information about the amount of marine snow and therefore how much deep-sea fish are getting for their dinner!

Trawling was not possible today due to the extensively rough terrain that was surveyed for hours in a desperate attempt to find a suitable piece of flat ground!


Weather Conditions

Still chilly and overcast with a touch of rain.  The sea has become a little rougher.


Tomorrows expected highlights

Tomorrow we will be conducting a ROV dive to the top of a mountain whose peak reaches 1000m depth.  Trawling will also be carried out in the vicinity of the summit, along with lander, UVP and CTD deployments.


Cruise journal

Follow the G.O.Sars-cruise from day to day:

June 2004

July 2004

456  78910

August 2004


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