dc.contributor.author | Bakke, Sigmund | |
dc.contributor.author | Bjørke, Herman | |
dc.date.accessioned | 2008-12-05T12:56:43Z | |
dc.date.issued | 1973 | |
dc.identifier.uri | http://hdl.handle.net/11250/114406 | |
dc.description.abstract | During the spring of 1971 divers made observations at the spawning grounds of the
Barents Sea capelin.
Large masses of capelin eggs were found at two localities: Loppa, (35-70 m depth)
and Nordvågen (12-18 m depth). The eggs were mixed down to a depth of 5 cm
with fine gravel (0.5-1.5 cm diameter).
Two behaviour patterns of the capelin were observed: Loosely packed schools
in the upper layers and dense circulating schools close to the bottom. The latter are
believed to be males waiting for ripe females.
Egg mortality caused by trawlers was experimentally investigated by dragging
trawl bobbins along the egg beds. Eggs stirred up by the bobbins showed higher
mortality (up to 10.2% after ten days incubation) than undisturbed eggs and eggs
from bobbin tracks (up to 2.5% mortality after ten days incubation). Less than 1%
of the eggs on the investigated spawning grounds is believed to be damaged by trawlers.
Diverse estimated a 5-10% decrease in the number of eggs on the spawning
grounds over a four week period. This was due to a drift of eggs largely caused by
wave action and water currents.
No predation of the capelin eggs was observed. | en |
dc.format.extent | 451916 bytes | |
dc.format.mimetype | application/pdf | |
dc.language.iso | eng | en |
dc.publisher | [Fiskeridirektoratets havforskningsinstitutt] | en |
dc.relation.ispartofseries | Fiskeridirektoratets skrifter, Serie Havundersøkelser | en |
dc.relation.ispartofseries | vol 16 no 4 | en |
dc.title | Diving observations on Barents Sea capelin at the spawning grounds off northern Norway | en |
dc.type | Research report | en |
dc.source.pagenumber | s. 140-147 | en |