Production Functions of the Norwegian bottom trawl fisheries of cod in the Barents Sea
. Catch and effort data of the cod fisheries of 18 Norwegian bottom trawlers have been obtained for the period 1971-1985. Statistical analyses have been carried out, assuming different types of production functions. Independent variables of the catch production are the per vessel trawl hours a day,...
| Main Authors: | , , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.37.311 http://tidley.nfh.uit.no/frank/arbeider/iifet98-eide.pdf |
| Summary: | . Catch and effort data of the cod fisheries of 18 Norwegian bottom trawlers have been obtained for the period 1971-1985. Statistical analyses have been carried out, assuming different types of production functions. Independent variables of the catch production are the per vessel trawl hours a day, and the biomass of the cod stock (3+). Per day biomass estimates have been calculated by polynomial interpolation of the per year estimates of the International Council for the Exploration of the Sea (ICES). By maximising the log-likelihood function by numerical methods, parameter estimates and performance indicators of the different models were obtained. The best result was obtained using a production model with an autocorrelated error term, and a catchability model allowing seasonal changes. The analysis of this model shows the stock-output elasticity to be 0.424, the effort-output elasticity to be 1.232, and the annual technological growth to be about 2%. The seasonal changes in catchabil. |
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