In September 2017, studies were conducted in the East Siberian Sea along the transect from a Indigirka delta to the ice edge at the outer shelf margin. The abundances of planktonic prokaryotes (N_PR) and free viruses (N_V), frequency of visibly infected prokaryotic cells (FVIC), and virus-mediated mortality of prokaryotes (VMPR) varied within (0.5–3.4) × 10⁶ (on average (1.67 ± 0.69) × 10⁶) cells/mL; (2.3–10.3) × 10⁶ (on average (5.28 ± 1.91) × 10⁶) viruses/mL; 0.6–2.5 (on average 1.1 ± 0.4) % of N_PR; and 4.5–22.3 (on average 9.0 ± 3.8) % of the total prokaryotic production, respectively. The proportions of viruses attached to prokaryotic cells (N_VPR) and suspended particles (N_VP) were 1.9–26.3 (on average 8.0 ± 5.0) % of N_V and 0.1–65.9 (on average 8.0 ± 13.3) % of N_V, respectively. High concentrations of detrital and mineral particles, to which a significant number of viruses were attached and, as a result, loss of their activity were recorded in the river–sea water mixing zone. In such a situation, the number of virus attacks on prokaryotes and cases of their infection decreased. There was a negative relationship between the concentration of suspended particles 0.5–5.0 μm in size and the abundance of infected prokaryotic cells. Thus, we conclude that viruses played a substantial role in controlling the abundance and production of heterotrophic prokaryotic plankton in the low-productive East Siberian Sea at the beginning of autumn.

Regional index terms: Russian Federation; East Siberian Sea.

Geographic bounding coordinates: 70–78° N; 150–165° E.

2017年9月，在东西伯利亚海沿从英迪吉尔卡三角洲到外陆架边缘冰缘的样带进行了研究。浮游原核生物（丰度Ñ _PR）和游离病毒（Ñ _V），明显地感染原核细胞的频率（FVIC），以及原核生物（病毒介导的死亡VMPR内（0.5-3.4）×10变化）⁶（平均（1.67±0.69）×10 ⁶）个细胞/ mL; （2.3–10.3）×10 ⁶（平均（5.28±1.91）×10 ⁶）病毒/ mL; N _PR的0.6–2.5（平均1.1±0.4）％; 分别为原核生物总产量的4.5％和22.3％（平均9.0±3.8％）。的附着于原核细胞（病毒的比例Ñ _VPR）和悬浮颗粒（Ñ _VP）为1.9-26.3（平均8.0±5.0）％的Ñ _V和0.1-65.9（平均8.0±13.3）的％Ñ _V， 分别。在河-海水混合区中记录了高浓度的碎屑和矿物颗粒，这些颗粒上附着有大量的病毒，因此，它们的活性下降。在这种情况下，对原核生物的病毒攻击次数及其感染病例减少了。大小介于0.5-5.0μm的悬浮颗粒浓度与感染的原核细胞数量之间存在负相关关系。因此，我们得出结论，在秋季开始之初，病毒在控制低产的东西伯利亚海中的异养原核生物浮游生物的丰度和生产中起着重要作用。

区域索引术语：俄罗斯联邦；东西伯利亚海。

地理边界坐标：70–78°N；150–165°E。