The use of predator-derived krill length-frequency distributions to calculate target strength
The relationship between krill abundance and predator performance is fundamental to an ecosystem-based approach to resource management. We propose a method using krill sampled from the diet of predators to provide a length-frequency distribution of krill at times when it is possible to run automated...
| Main Authors: | , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2001
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| Subjects: | |
| Online Access: | https://research-portal.st-andrews.ac.uk/en/researchoutput/the-use-of-predatorderived-krill-lengthfrequency-distributions-to-calculate-target-strength(c988790c-f9c0-46f9-8c7a-99c523f710e9).html http://www.scopus.com/inward/record.url?scp=0041078857&partnerID=8YFLogxK |
| Summary: | The relationship between krill abundance and predator performance is fundamental to an ecosystem-based approach to resource management. We propose a method using krill sampled from the diet of predators to provide a length-frequency distribution of krill at times when it is possible to run automated shipboard acoustic systems but not to conduct scientific netting, i.e during logistic/resupply operations, This will allow a robust estimate of krill abundance to be calculated from acoustic data. Changes in the length-frequency distribution of krill over a period of a few weeks produced a 10% difference in TS, whereas simultaneous samples from predators and nets produced only a 1% difference, illustrating the need for simultaneous length-frequency data. By integrating data from land-based predators directly with automated on-board data collection systems it will be possible to gain important estimates of krill biomass at times of the season hitherto unavailable from shipboard scientific surveys. |
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