TITLE: Estimating catch at age of commercial fish by combining data from several sources.
SPEAKER: David Hirst (Norwegian Computing Center)
VENUE: Laboratory's Conference Room, FRS Marine Laboratory, Aberdeen
TIME: Tuesday 22nd February at 4pm (tea and coffee from 3:30 pm)
ABSTRACT: One of the duties of all European countries with commercial fisheries is toreport the catch at age of all species caught by their fishing fleet. From2005 these figures will also have to include a measure of uncertainty. Themethods currently being used by most countries can only give pointestimates, have a large subjective element, and are very time consuming. Afast and reliable method for the analysis that could be used across all ofEurope would be very desirable, but one of the problems is that the data iscollected in many different ways in different countries. In order to address these problems the Norwegian Computing Center, alongwith the Norwegian Institute of Marine Research, has developed a Bayesianhierarchical model which can analyse data from any of the various nationalsampling schemes. The modelling approach makes it possible to combinedifferent kinds of data correctl
y via the likelihood, and the uncertaintycomes directly from the posterior distributions of the various parameters. We can also include other factors such as age-reading errors, which are verysignificant for many species.
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Claus-D. Mayer | http://www.bioss.ac.uk
Biomathematics & Statistics Scotland | email: [log in to unmask]
Rowett Research Institute | Telephone: +44 (0) 1224 716652
Aberdeen AB21 9SB, Scotland, UK. | Fax: +44 (0) 1224 715349
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