Распределение пурпурного кальмара Sthenoteuthis oualaniensis Lesson (Cephalopoda: Ommastrephidae) в северной части Аравийского моря
A complex survey was carried out on board a scientific research vessel «Dmitry Stefanov» with application of a pelagic trawl in the upper sound-scattering layer (SSL) at the depths from 0 to 120 m in the northern Arabian Sea, in the area of 200-mile zone of foreign states to 15° N from April, 23 to May 14, 1989. This area was characterized by impoverished teutofauna (5 species), in comparison with the southern Arabian Sea and the equatorial area, where 10 and 15 cephalopod species were recorded in the catches, respectively. Sestonic biomass varied from 50 to 2520 mg/m3 and on average made up 392 mg/m3 (207 mg/m3, excluding salps). The highest values of plankton biomass were recorded in the north-western part of the studied area. The sections of water rise on the periphery of the anticyclonic vortex and in the area of divergence, where the Arabian surface water «outcropped» closer to the oceanic surface, were especially productive. In the areas of water rise, the SSL tapered down to 25-40 m and was located at the depths from 10 to 110 m, and in the areas of lowering it was located in the range of depths from 25 to 185 m. The catches of the purpleback flying squid varied from 2.5 to 130 kg per hour, its abundance was fluctuating from 11 to 1216 ind. per hour. The average catch was 24.7 kg per hour (298 ind. per hour). The biggest catches were recorded in the area between 16° and 20° N, bordering on the economic zone of Oman. At the night-light stations, the purpleback flying squid biomass varied in the range from 0 to 150 kg/km2 and on average made up 35.9 kg/km2. The most productive areas were also located in the northern part of the studied region. It could be assumed that the formation mechanism for the purpleback flying squid aggregations in the upper SSL is based on the peculiarities of its feeding behaviour; the tapering productive layer of the Arabian water mass in the areas of water rise increases the concentrations of food zooplankton and Myctophidae, which attracts squids and leads to formation of their aggregations of commercial value.
| Main Authors: | , |
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| Format: | Conference Material biblioteca |
| Language: | Russian |
| Published: |
Kerch Branch ("YugNIRO") of FSBSI "AzNIIRKH"
2017
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| Subjects: | Sthenoteuthis oualaniensis, Purpleback flying squid, Exclusive economic zone, Catch statistics, Plankton, Biomass, Night-light station, Abundance, Food organisms, Commercial catches, |
| Online Access: | http://hdl.handle.net/1834/11062 |
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