Zooplankton biomass has been monitored on joint Norwegian-Russian surveys in late summer and autumn since the 1980s. We report here on zooplankton biomass in three size fractions (<1, 1–2, and > 2 mm in screen mesh opening) obtained with WP-2 plankton net (180 μm mesh size) hauled vertically over the water column from near bottom to the surface for the period 1989–2020. The number of samples (stations) collected each year has been about 100–200, with a total number of 4543 stations for the whole data set. The size composition of zooplankton reflected by the three fractions has shown remarkable stability, with about 50% of biomass contained in the medium fraction (made up largely of Calanus species), about 1/3 in the small fraction (36%), and 16% in the large fraction. The depth integrated biomass was generally larger in basins compared to shallower bank areas. The temporal (interannual) pattern of change was characterized by a marked peak in biomass in 1994 and 1995 with values up to >20 g dry weight (dw) m⁻², driven to large extent by the small size fraction. Subsequently the biomass decreased to lower values but with a divergence of relatively high values (10–15 g dw m⁻²) in the inflow area of Atlantic water in southwest, and low values (2–6 g dw m⁻²) in the central area. The difference is interpreted to reflect an increase in a second summer generation of Calanus finmarchicus in the Atlantic water and a decrease of C. glacialis in the central area. The zooplankton biomass fluctuated inversely with the biomass of the Barents Sea capelin (Mallotus villosus) stock, reflecting a top-down predation effect. However, biomass was also negatively correlated with temperature of the Atlantic water, suggesting an additional and confounding effect of climate variability and change. The decrease in biomass of the central area used as a forage area by capelin, was associated with a shift to dominance by the small size fraction. This is likely an effect of predation and could be associated with a lower trophic conversion efficiency from phytoplankton to planktivorous fish and higher trophic levels by smaller zooplankton (smaller copepods such as Pseudocalanus and others) compared to the larger Calanus species.

自 1980 年代以来，挪威-俄罗斯在夏末和秋季的联合调查中监测了浮游动物的生物量。我们在此报告使用 WP-2 浮游生物网（180 μm 筛孔尺寸）从近底部垂直拖到水柱上获得的三种尺寸分数（筛网开口中的<1、1-2 和 > 2 mm）的浮游动物生物量。 1989-2020 年期间的表面。每年采集的样本（站）数量约为 100-200 个，整个数据集共有 4543 个站。三个馏分反映的浮游动物的大小组成表现出显着的稳定性，约 50% 的生物量包含在中等馏分中（主要由Calanus组成）种），约 1/3 为小部分（36%），16% 为大部分。与较浅的岸边区域相比，盆地的深度综合生物量通常较大。变化的时间（年际）模式的特点是在 1994 年和 1995 年生物量出现显着峰值，其值高达 >20 g 干重 (dw) m ^-2，这在很大程度上是由小尺寸部分驱动的。随后，生物量下降到较低的值，但在西南部大西洋水流入区的值相对较高（10-15 g dw m ^-2）和在西南部的低值（2-6 g dw m ^-2）的差异。中心区。这种差异被解释为反映了夏季第二代Calanus finmarchicus的增加在大西洋水域和中部地区冰川 C. glacialis的减少。浮游动物生物量与巴伦支海毛鳞鱼 ( Mallotus villosus ) 种群的生物量成反比波动，反映了自上而下的捕食效应。然而，生物量也与大西洋水的温度呈负相关，这表明气候变率和变化的附加和混杂影响。毛鳞鱼用作草料区的中心区域生物量的减少与小尺寸部分向主导地位的转变有关。这可能是捕食的影响，可能与从浮游植物到浮游食性鱼类的营养转换效率较低以及较小的浮游动物（较小的桡足类，如Pseudocalanus和其他）与较大的Calanus物种相比。