GLM standardisation of recent commercial CPUE data for Greenland halibut for Canada, Portugal and Spain which allows for finer spatial stratification.
Updated CPUE data for the Canadian, Portugese and Spanish fleets are standardised using GLMs with an overdispersed Poisson error structure, and allowing for finer spatial stratification than the Division level to correct for possible redistribution of fishing towards higher density areas. Results fo...
| Main Authors: | , , |
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| Format: | Report |
| Language: | English |
| Published: |
University of Cape Town
2009
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| Subjects: | |
| Online Access: | http://hdl.handle.net/11427/17929 https://open.uct.ac.za/bitstream/11427/17929/1/Brand%c3%a3o_GLM_standardisation_2009.pdf |
| Summary: | Updated CPUE data for the Canadian, Portugese and Spanish fleets are standardised using GLMs with an overdispersed Poisson error structure, and allowing for finer spatial stratification than the Division level to correct for possible redistribution of fishing towards higher density areas. Results for standardisations without year-interactions do show the recent increases evident in the nominal CPUE data; these results are independent of the extent of spatial stratification, and are broadly compatible with previous standardisation exercises, except for now showing a higher rate of recent increase in the Canadian case. However, the introduction of either Division or depth interaction terms with year in the standardisation does reduce the extent of the recent rate of increase. |
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