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Dawn haze
Dawn Haze
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The second week

Progress to date: 28 October 2010.

We have now completed the off-shelf areas of the pelagic survey and have start worked in the western inshore region. Work has been going smoothly, and the weather has become increasingly calm over the last week. Most mornings it is glassy calm with a light haze, mostly dust clouds blowing offshore

Progress on the shelf is slowed considerably by large numbers of boats and gear anchored at night  limited transect lines to daytime only.

Fishing boat roadblock

Fishing boat roadblock

To date we have completed 42 tows and caught over 80 species from a total catch of almost 2300 kg. Almost one third of the total came from a single tow.

Gawins work

Gavin admires his work

including Decapterus russeli (top), Dusummerieria acuta (middle) and two species of Sardinella (bottom). 

Small pelagics

Small pelagic fish

The 17 offshore oceanographic stations (CTD, multinet and phytoplankton tows) are complete, along with the shrinking of many decorated polystrene cups that were attached to the CTD.
Tow Multinet

Retrieving the multinet plankton samples

The diurnally-migrating mesopelagic layer has covered almost all of the offshore region, with higher densities to the west, particularily on the shelf break. The dominant species has been Benthosema fibulatum with small numbers of other species. We also caught one species that was not previously recorded from this area.

Benthosema in abundance

Our cup runneth over: a catch of Benthosema fibulatum

We have also carried out multi-beam work on two seamounts on the Murray Ridge. There was very little biological backscatter from above the seamounts, perhaps due to the very low concentrations of dissolved oxygen in the surrounding waters. Interestingly, we did note an increased density of flying fish while above the seamounts.