Mar.fleets : an R package for integrating commercial catch and at-sea observer data from Maritimes region / by Mike McMahon and Heather Bowlby. : Fs97-6/3450E-PDF

"For Maritimes Commercial Fisheries, information on non-retained catch (i.e. observer data) is stored in a separate database from retained catch information (i.e. commercial landings). While the observer database includes sufficient information to identify vessels, it does not include the suite of licencing information used to associate vessels with fleets. Further, neither database includes a mechanism for reliably associating the recorded trips and sets in one with those recorded in the other. Maritimes staff frequently need to identify all of the participants in a fishery, and extract fleet-specific data associated with the commercial landings as well as any observed catch. To better understand the wider impact of a given fishery on non-retained species, it is often imperative to know which commercial trips are associated with which observed trips to correctly prorate catch data. This report describes Mar.fleets, a new R package offering Maritimes users a unified approach for reliably: 1) identifying fleets, 2) extracting commercial landings, 3) matching commercial and observed trips and sets, and 4) extracting the matched observer data. Each of the underlying functions are described, as are the mechanisms for fleet identification and inter-database matching. A key component of the package consists of fleet-specific "wrapper functions", which were developed to ensure consistent and repeatable extractions by hard-coding fleet-specific information. Ancillary functions for summarizing and mapping the results are also described"--Abstract, page iv.

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publications.gc.ca/pub?id=9.905217&sl=1

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