Fish communities on the slope of the eastern Norwegian Sea
Fish communities on the slope of the eastern Norwegian Sea
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DOI：
10.1080/00364827.1999.10420452
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发表时间：
1999-01-01
期刊：
影响因子：
--
通讯作者：
Gordon, JDM
中科院分区：
文献类型：
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作者：
Bergstad, OA;Bjelland, O;Gordon, JDM
对挪威外海斜坡300-2050米深度区间的底拖网数据进行了分析，以研究鱼类生物量和相关物种组合的分布情况。据推测，在温暖的大西洋水团和寒冷的挪威海深水之间的明显的水文锋面，加上食物供应随深度和距离陆架的减少，构成了挪威海东部大陆坡上的生物组合。在720米处，当越过与水文锋面相关的0 ℃等温线时，鱼类生物量突然下降。锋面区之下，鱼类生物量只有11%以上，并随着深度的增加进一步下降。在上游斜坡沃茨，鱼类生物量随纬度的增加而增加，在深层寒冷的斜坡沃茨，北极种如冷狼和深海副狮子鱼占优势。与600-720 m温度梯度相关的高鱼类生物量主要归因于少数大型和/或丰富的北极圈物种，即格陵兰大比目鱼Reinhardtius glossoides，红鱼Aptites mentella和S. marinus，roughhead cruadier Macrourus berglax，Raja hyperborea.在较浅和温暖的上斜坡沃茨的物种组合发生类似于与邻近的深陆架地区强烈影响的大西洋水团。
Bottom trawl data from the depth interval 300-2050 m on the slope off Norway were analysed to study distribution of fish biomass and the associated species assemblages. It is hypothesised that the pronounced hydrographic front between the warm Atlantic Watermass and the cold Norwegian Sea Deepwater, combined with a declining food supply with depth and distance from the shelf, structure the assemblages on the continental slope of the eastern Norwegian Sea.From a high level at the shelf edge and upper slope, the fish biomass declined abruptly at about 720 m when crossing the 0 degrees C-isotherm associated with the hydrographic front. Beneath the frontal zone, the fish biomass was only 11% of that above it and decreased further with increasing depth. In upper slope waters, the fish biomass increased with increasing latitude.Arctic species such as Lycodes frigidus and Paraliparis bathybius were dominant in the deep cold slope waters. The high fish biomass associated with the steep temperature gradient at 600-720 m was mainly attributable to a few large and/or abundant boreo-arctic species, i.e. Greenland halibut Reinhardtius hippoglossoides, redfishes Sebastes mentella and S. marinus, roughhead grenadier Macrourus berglax, and Raja hyperborea. In the shallower and warmer upper slope waters a species assemblage occurred which resembled that associated with adjacent deep shelf areas strongly influenced by the Atlantic Watermass.