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pelagic schools
Schooling small pelagics on the Balochistan shelf 
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End of one survey and on with the next

To Nov 4th 2010

We have reached the end of the first of our two surveys focused on the inshore small pelagic and offshore mesopelagic species. Last week we completed the western offshore stratum and the western shelf (Balochistan) stratum. The narrow Balochistan shelf area was the only area where we saw schools of pelagic fish. 

The ship returned to Karachi on October 31st to change the vessel crew and some of the scientific staff.

pelagic survey staff

Pelagic Survey Staff

We began the second survey on Nov 2nd with fresh food, fuel and staff. This demersal survey will take three weeks in total, surveying a planned total of 95 selected locations on the continental shelf of Pakistan. Although the main source of data will be the bottom trawl, the acoustic systems will be used to assess the distribution and availability of demersal species in the trawl path.

With two full days complete on the demersal survey we have made 11 trawl tows and conducted 7 oceanographic sampling stations. Both the catch rates and the diversity are far higher using the bottom trawl than were seen in the pelagic trawl tows made on the first leg. We have already caught 101 distinct taxa compared to a total of 89 taxa in the entire pelagic survey last month. For comparison, the maximum number of taxa in a single tow was 19 on the pelagic survey while we have already had a peak of 47 in one tow on the demersal survey.

fish diversity sample

Fish Diversity Sample

The extensive dense layers of jellyfish which we had seen on the pelagic survey were well represented in the demersal catches as well.

jello of the sea

Jello of the sea

And sea snakes are a regular part of the catches from both demersal and pelagic trawls on the shelf 
snakes on the boat

Sea snakes