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首页> 外文期刊>ICES Journal of Marine Science >Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s
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Synchronous ecological regime shifts in the central Baltic and the North Sea in the late 1980s

机译：1980年代后期，波罗的海中部和北海的生态同步变化

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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. helgolandicus (NS) and Temora longicornis and Acartia spp. (CBS) were persistently abundant. These changes in 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 NS 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.
机译：北大西洋涛动指数是北大西洋地区气候变化的主要模式，在1980年代后期（1987-1989年）从负变为正。这导致北海（NS）和波罗的海中部（CBS）的生态体制发生变化，这涉及到这两个相邻大陆架海中上层的所有营养级。影响关键的物理和生物过程的空气和海面温度升高是主要的直接和间接驱动力。 1987年之后，两个系统中的浮游植物生物量均增加，并且生长期延长。两种海洋中的植物和浮游植物群落的组成发生了显着变化，例如CBS中鞭毛藻的丰度增加而硅藻的丰度降低。鱼饲料中必不可少的关键co足类物种的生物量发生了明显变化。丰富的Calaus finmarchicus（NS）和Pseudocalanus sp。 （CBS）降至较低水平，而C. helgolandicus（NS）和Temora longicornis和Acartia spp。 （CBS）持续丰富。不同co足类物种生物量的这些变化对生物量，渔业和主要鱼类的着陆产生了重大影响：北海鳕鱼数量下降，CBS中的鳕鱼含量保持较低水平，CBS幼虫达到前所未有的高生物量水平，从而导致高产。 NS和CBS中同步的政权转移导致了两个海洋生态系统的深刻变化。但是，对于相同的气候变化，三种种群的鱼类种群对自下而上的机理的反应是非常不同的。

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