Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s
Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s
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DOI：
10.1016/j.icesjms.2005.04.024
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发表时间：
2005-10-01
影响因子：
3.3
通讯作者：
Wasmund, N
中科院分区：
文献类型：
--
作者：
Alheit, J;Möllmann, C;Wasmund, N
北大西洋涛动是北大西洋区域气候变化的主要模式，其指数在1980年代后期（1987-1989年）从负阶段变为正阶段。这导致了制度的变化，在北海（NS）和波罗的海中部（CBS）的生态，其中涉及这两个相邻的大陆架海域的浮游生物的所有营养水平。空气和海洋表面温度的上升影响到关键的物理和生物过程，是主要的直接和间接驱动力。1987年后，两个系统中的浮游植物生物量增加，生长季节延长。两个海区浮游植物和浮游动物群落组成变化显著，其中，CBS海域甲藻丰度增加，硅藻丰度减少。鱼类食物中必不可少的关键桡足类物种的生物量发生了显著变化。芬兰哲水蚤（NS）和拟哲水蚤（CBS）的产卵量下降到较低水平，而拟哲水蚤（C. Helgolondicus（NS）和长角Temora longicornis和蜱螨属（Acartiaspp.）(CBS)一直都很丰富不同桡足类物种的生物量的这些变化对生物量、渔业和主要鱼类的上岸量产生了巨大的影响：北海鳕鱼下降，CBS中的鳕鱼保持在低水平，CBS鲱鱼达到了前所未有的高生物量水平，导致高产。MS和CBS的同步政权转变导致了这两个海洋生态系统的深刻变化。然而，鱼类种群的反应，自下而上的机制所造成的相同的气候变化是非常不同的三个鱼类种群。(c)2005年国际海洋考察理事会。由爱思唯尔有限公司出版。保留所有权利。
The index of the North Atlantic Oscillation, the dominant mode of climatic variability in the North Atlantic region, changed in the late 1980s (1987-1989) from a negative to a positive phase. This led to regime shifts in the ecology of the North Sea (NS) and the central Baltic Sea (CBS), which involved all trophic levels in the pelagial of these two neighbouring continental shelf seas. Increasing air and sea surface temperatures, which affected critical physical and biological processes, were the main direct and indirect driving forces. After 1987, phytoplankton biomass in both systems increased and the growing season was extended. The composition of phyto- and zooplankton communities in both seas changed conspicuously, e.g. dinoflagellate abundance increased and diatom abundance decreased in the CBS. Key copepod species that are essential in fish diets experienced pronounced changes in biomass. Abundance of Calanus finmarchicus (NS) and Pseudocalanus sp. (CBS) fell to low levels, whereas C. helgolondicus (NS) and Temora longicornis and Acartia spp. (CBS) were persistently abundant. These changes ill biomass of different copepod species had dramatic consequences on biomass, fisheries, and landings of key fish species: North Sea cod declined, cod in the CBS remained at low levels, and CBS sprat reached unprecedented high biomass levels resulting in high yields. The synchronous regime shifts in MS and CBS resulted in profound changes in both marine ecosystems. However, the reaction of fish populations to the bottom-up mechanisms caused by the same climatic shift was very different for the three fish stocks. (c) 2005 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.