The dynamics of prespawning capelin (Mallotus villosus socialis) off the West Kamchatka coast
Pacific capelin catches for the period 1961–2000 are analysed. Biological data are used to show that spawning-stock biomass, spawning time, and size of the spawning areas were not stable. Estimates of stock biomass were made from a helicopter. Stock size, in terms of catch and estimated spawning-sto...
| Published in: | ICES Journal of Marine Science |
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| Main Author: | |
| Format: | Text |
| Language: | English |
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Oxford University Press
2002
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| Online Access: | http://icesjms.oxfordjournals.org/cgi/content/short/59/5/1006 https://doi.org/10.1006/jmsc.2002.1280 |
| Summary: | Pacific capelin catches for the period 1961–2000 are analysed. Biological data are used to show that spawning-stock biomass, spawning time, and size of the spawning areas were not stable. Estimates of stock biomass were made from a helicopter. Stock size, in terms of catch and estimated spawning-stock biomass, fluctuated in a two-year cycle, and differed by a factor of 10 or more from year to year. Every 20–22 years, the cycle shifted from even- to odd-numbered years. Capelin have also seemingly started to spawn earlier, coincident with a decrease in sunspot activity. The highest occupancy of spawning grounds was in 1990, when 90% of the possible habitat was used. Minimum occupation of spawning grounds was about 3%, in 1984. |
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