Статистический анализ размерного состава уловов антарктического криля Euphausia superba в зависимости от орудий и технологии лова
Current Antarctic krill fisheries are carried out in the Atlantic Antarctic using conventional catch methods by means of midwater otter- and beam-trawls or continuous fishing technology. The mesh size in codend of these fishing gears ranges from 11 to 20 mm. As a result of such mesh size variety, there may be net selectivity. Spatial and temporal variability of krill length is observed in the fishing areas; it could overlap differences in the selectivity of fishing gear, including selectivity of mesh size in codends. Difference in the mean krill length in catches was insignificant, when mesh size in codend was 14 mm and conventional and continuous fishing methods were used. However, this difference was statistically significant under conditions of mesh size equaling 14, 16 and 20 mm. The number of small krill individuals was decreasing with the increase of mesh size in codend, and the percentage share of individuals in modal classes was increasing. It is possible that dissimilarities exist between the selectivity of codends with mesh size 14, 16 and 20 mm in relation to Antarctic krill length. However, krill samples, taken for fishery purposes from various fishing gears, can be considered identical and be combined into one unified sample for further investigation.
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| Format: | Journal Contribution biblioteca |
| Language: | Russian |
| Published: |
2017
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| Subjects: | Statistical analysis, Fishing area, Euphausia superba, Antarctic krill, Krill fisheries, Catch per effort, Catch statistics, Size composition, Fishing seasons, Fishing methods, |
| Online Access: | http://hdl.handle.net/1834/11025 |
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| Summary: | Current Antarctic krill fisheries are carried out in the Atlantic Antarctic using conventional catch methods by means of midwater otter- and beam-trawls or continuous fishing technology. The mesh size in codend of these fishing gears ranges from 11 to 20 mm. As a result of such mesh size variety, there may be net selectivity. Spatial and temporal variability of krill length is observed in the fishing areas; it could overlap differences in the selectivity of fishing gear, including selectivity of mesh size in codends. Difference in the mean krill length in catches was insignificant, when mesh size in codend was 14 mm and conventional and continuous fishing methods were used. However, this difference was statistically significant under conditions of mesh size equaling 14, 16 and 20 mm. The number of small krill individuals was decreasing with the increase of mesh size in codend, and the percentage share of individuals in modal classes was increasing. It is possible that dissimilarities exist between the selectivity of codends with mesh size 14, 16 and 20 mm in relation to Antarctic krill length. However, krill samples, taken for fishery purposes from various fishing gears, can be considered identical and be combined into one unified sample for further investigation. |
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