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Project staff sorting a daytime mesopelagic (towed at 315 m) trawl sample.
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The first week

Progress to date: 19 October 2010

The ship arrived as scheduled in Karachi on 10 October 2010 and a pre-survey reception was held including a tour of the ship for the Minister of Livestock and Dairy Development (responsible for fisheries), the Norwegian Ambassador and other dignitaries.

We sailed shortly after 12:00 noon local time on 12 October 2010. A planned acoustic calibration in the waters outside Karachi where some shelter was offered by Cap Monze was postponed as conditions were still too rough. Hopefully the swells will decline over the next few days or a week as the monsoon winds drop between seasons. The first acoustic transects began at 19:15 that evening.

Sindh stratum, the eastern half of the shelf area, was completed on schedule with approximately 1400 km of track steamed and 12 pelagic trawl hauls. . Fish catches with mid-water trawl tows and sorted, identified, weighed, measured and counted. Our schedule was setback at this point when an ill staff member was returned to Karachi, taking about 24 hours in total. Upon the return to the survey track the deep-water hydrographic stations began with CTD, water sampling, zooplankton (multinet) and phytoplankton hauls.

Acoustic echograms have been dominated by scattering layers with well-defined schools of fish rarely appearing. The catches from both schools and the scattering layers all seem to be dominated by mesopelagic fish such as myctophids and other stomiiforms and a large proportion of jellyfish in the continental shelf areas.

Catch

Mesopelagic mixture including Bristlemouths (Gonostomatidae), jellyfish and Myctophids (Benthosema fibulatum). The average length is only about 5 cm for these fish.


The diurnal vertical migration of these species is captured perfectly in the echograms at dawn and dusk each day.
Vertical migration example

The evening ascent of the mesopelagic layer from below 300m to about 50 m in about an hour and a half.


Signs of other species groups, including most commercially important species, have been disappointingly scarce. Few fish schools have been detected and only a handful of fish longer than 15 cm have been caught.