Reference points for optimal fish stock management: A lesson to be learned from the Northeast Arctic cod stock

Marine Policy

Volumn 20, Issue 6, 1996, Pages 447-462

  Nakken, Odd ^a   Sandberg, Per ^b   Steinshamn, Stein Ivar ^c  

^a INSTITUTE OF MARINE RESEARCH   (Norway)

^b INSTITUTE OF NUTRITION   (Norway)

^c NORWEGIAN SCHOOL OF ECONOMICS   (Norway)

Author keywords

[No Author keywords available]

Indexed keywords

ARCTOGADUS GLACIALIS; GADUS MORHUA; GADIFORMES;

FISHERY MANAGEMENT; FISHERY RESOURCES; GADOID FISHERIES; SHARED STOCKS; TRANSBOUNDARY RESOURCES;

ARCTIC OCEAN;

EID: 0030423815     PISSN: 0308597X     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0308-597X(96)00033-4     Document Type: Article

References (20)

1. O Nakken, 'Causes of trends and fluctuations in the Arcto-Norwegian cod stock' ICES Marine Science Symposium, Vol 198, 1994, pp 212-228.
2. T Haug, V Lindstrøm, K T Nilssen, I Røttingen and H J Skaug, 'Diet and food availability for Northeast Arctic minke whales Balanoptera acutorostrata, International Whaling Commission, SC/47/NA2.
3. A M Ajiad, S Mehl, K Korsbrekke, A V Dolgov, V A Korzhev, V L Tretyak and N A Yaragina, 'Tropic relationships and feeding-dependent growth in the Northeast Arctic cod', Proceedings of 5th PINRO-IMR Symposium, Murmansk, August 1991, Institute of Marine Research, Bergen, 1992.
4. K I Ugland, K A Jødestol, P E Aspholm, A B Krøyer and T Jakobsen, 'Fish consumption by invading harp seals off the Norwegian coast in 1987 and 1988, ICES Journal of Marine Science, Vol 50, 1993, pp 27-38.
5. T Jakobsen, 'Management of Northeast Arctic cod - past, present - and future?', Proceedings of Symposium on Management Strategies for Exploited Fish Populations, Anchorage, Alaska, October 1993.
6. V P Serebryakov, 'Predicting yearclass strength under uncertainties related to survival in the early life history of some North Atlantic commercial fish', NAFO Scientific Council Studies, Vol 16, 1991, pp 49-50.
7. T Jørgensen, 'Long-term changes in age at sexual maturity of Northeast Arctic cod (Gadus morhua L.)' (ICES Journal of Marine Science) Vol 46, 1990, pp 235-248.
8. See Appendix for further explanation of natural mortality (M).
9. T Jakobsen, 'Biological reference points for Northeast Arctic cod and haddock', ICES Journal of Marine Science, Vol 49, 1992, pp 155-166.
10. Generally, economic yield is defined as the sum of consumers' and producers' surplus. Since fishermen are effectively price-takers, only producers surplus matters in this connection.
11. Even though fixed costs affect the net economic yield in optimum, these costs occur irrespective of catch levels and do therefore not affect the optimum itself.
12. Norwegian official statistics, 'Fiskeristatistikk 1990-1991', Central Bureau of Statistics, 1993.
13. The aim of this analysis is to evaluate the socio-economic yield from the cod stock. This yield is simply revenue less variable costs, and may be used by the society for various purposes. The consumer price index (CPI) therefore seems to be a good deflator for both revenue and yield.
14. S I Steinshamn, 'Torsk som nasjonalformue: En disaggregert modell', SNF-rapport nr 61/1993 (Stiftelsen for samfunns-og næringslivsforskning, Bergen), 1993.
15. The following linear relationship is established: C(F) = 456.6 + 2345.1 × F. This equation is established by calculating costs per trawl-hour and then estimating fishing mortality as a linear function of the number of trawl-hours. The costs are calculated in million 1988-NOK. (C = costs, F = fishing mortality).
16. Anon, Report of the Arctic Fisheries Working Group, ICES, Copenhagen, August 1995.
17. Ø Ulltang, 'Potential gains from improved management of the Northeast Arctic cod stock', Fisheries Research, Vol 5, 1987, pp 319-330.
18. Anon, Report of the Arctic Fisheries Working Group, ICES, Copenhagen, August-September 1993.
19. Using statistical methods, we can measure the correlation between the two variables and indicate it on a scale ranging from 0 to 1. For the 1970-1989 period, within which technological improvements or strict regulations are not expected to explain large proportions of the catch, the correlation was measured to 0.85. Within this period the size of the spawning stock explains 85% of the variation in the catch levels during the Lofoten fishery.
20. FAO, 'Reference points for fishery management. Their potential application to straddling and highly migratory resources', FAO Fisheries Circular No. 864, Firm/ C864, Rome, 1993.