International Council for the Exploration of the Sea
WKCPUEFFORT 2011.pdf (2.83 MB)

Report of the Workshop on the utility of commercial CPUE and VMS data in assessment (WKCPUEFFORT)

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posted on 2022-10-06, 11:23 authored by ICESICES

The Workshop on the utility of commercial CPUE and VMS data in assessment (WKCPUEFFORT) was held at ICES headquarters 5-7 April, 2011. The workshop was chaired by Norman Graham, Marine Institute, Ireland and attended by twelve partici-pants. The objective of the workshop was to review and consider the utility of vessel monitoring systems (VMS) and other novel data acquisition systems and how these could be used to improve the utility of CPUE data for assessment purposes. VMS and other electronic monitoring systems are relative new developments and are largely used for compliance purposes. However, the integration of VMS and commercial catch data pro-vides the opportunity to provide fine scale spatial distribution maps of fishing effort and catch distribution maps. Much of the most recent work has focussed on the interpretation of VMS data to separate fishing from non-fishing activity and integration of VMS with landings data. Research beyond the production of mapping is only now beginning to emerge from the scientific community but in many respects the use of spatially refined catch data for scientific and management purposes is still in its infancy. VMS data, in combination with other data sources such as information from fishery independent sur-veys are now being used for the evaluation of spatial and temporal closures, but the use of VMS for traditional stock assessment purposes is hampered by the lack of time series and that many assessment techniques lack spatial considerations beyond stock boundary definition. The workshop considered the output from a recent EU funded project “Devel-opment of tools for logbook and VMS data analysis” and concluded that the common data format proposed should be used to ensure data and exchange compatibility. The work presented shows how VMS data can be used in conjunction with logbook data to spatially identify strata where linked VMS and logbook data was used to spatially refine commercial LPUE indices. Indices can be biased if the spatial distribution of fishing effort changes over time. Identifying strata based on homogenous, spatially refined catch com-position data, can be used to provide an unbiased LPUE trends, contrasting stratified LPUE and non-spatially refined LPUE for some species shows marked differences. As time series of VMS data increases, spatially refining commercial tuning fleets using such approaches should be considered during stock benchmarks. Recognising that species dis-tribution is strongly influenced by habitat type, the workshop considered the data types required to generate standardised abundance indices not only based on spatial distribu-tion, but also to incorporate habitat type. The workshop was asked to provide guidelines on when to use commercial catch data. While identifying the main potential sources of bias, the workshop concluded that the decision to include or exclude commercial catch data is one best left to individual stock coordinators and that many of the issues are com-pliance rather than scientifically related. The workshop then considered how VMS and new monitoring systems could be useful in terms of providing better estimators of effort and how more systematic and widespread data collection of fishing gear parameters would help refine effort metrics. For example instead of estimating effort in terms of time, trawl sensors could be used to quantify swept volume or area. A potential statistical method for standardisation of effort and CPUE is presented. The workshop concluded that while the use of VMS data has been limited in terms of assessment purposes, the in-creasing time series and access to VMS and other novel data systems warrants more de-tailed investigation and this would be best achieved through the formation of a dedicated research projects.


Published under the auspices of the following ICES Steering Group or Committee

  • ACOM

Published under the auspices of the following ICES Expert Group or Strategic Initiative



ICES Expert Group Reports

Recommended citation

ICES. 2011. Report of the Workshop on the utility of commercial CPUE and VMS data in assessment (WKCPUEFFORT), 5-7 April 2011, Copenhagen, Denmark. ICES CM 2011/ACOM:49. 71 pp.

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