Advent of another day
Posted by Paul on
17 December 2011
What a difference a day (or two) makes! The wind has
finally dropped and (after a bit of a lag) the sea swell has
flattened out too.
So after a (not too unpleasant) transit back east we arrived at
our survey site late on Friday evening. The conditions were still a
little marginal when we arrived. However, we were able to
re-calibrated the multibeam system with a new sound velocity
profile before attempting to deploy the HamCam (see 'Multibeam
Celebrations'). After two stations we decided that the sea state
was still not calm enough to carry on using the HamCam so continued
grabbing with the Shipek grab up until after breakfast.
After breakfast the sea state had reduced sufficiently for us to
begin Hamon grabbing again. After completing several stations we
deployed the 2m Jennings Beam Trawl (see below).
We use the 2m scientific beam trawl to sample epifaunal species
(animals which live on the surface of the seabed). These
animals include hermit crabs, starfish, sea urchins and flatfish.
Once the trawl has been landed on deck our scientists count, weigh
and identify all the animals before returning them to the sea (see
below).
The collection of both epifaunal species (using the beam trawl)
and infaunal species (animals which live buried within the seabed
sediments), using the Hamon grab, allows us to get a full picture
of the seabed animal communities that are present across the survey
area.
Today we reached the half way stage of our Eastern English
Channel survey. Everything crossed (not just fingers this
time) that the weather holds for the next few days so that we can
finish this survey area before moving into the outer Thames.
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