TY - JOUR

T1 - Rapid unpredicted changes in the stratification of marine lake Mogilnoe (Kildin Island, the Barents Sea) through the early 21st century

AU - Strelkov, Petr

AU - Stogov, Igor

AU - Krasnova, Elena

AU - Movchan, Ekaterina

AU - Polyakova, Nataliya

AU - Goldin, Sergei

AU - Ivanov, Mikhail

AU - Ivanova, Tatiana

AU - Malavenda, Sergey

AU - Fedyuk, Mikhail

AU - Shunatova, Natalia

N1 - Strelkov, P., Stogov, I., Krasnova, E., Movchan, E., Polyakova, N., Goldin, S., Ivanov, M., Ivanova, T., Malavenda, S., Fedyuk, M., & Shunatova, N. (2019). Rapid unpredicted changes in the stratification of marine lake Mogilnoe (Kildin Island, the Barents Sea) through the early 21st century. Polar Research, 38. https://doi.org/10.33265/polar.v38.3394

PY - 2019/12/19

Y1 - 2019/12/19

N2 - Lake Mogilnoe is a rare example of an anchialine lake (with subterranean connection to the ocean) in the Arctic, a refuge for landlocked populations of marine organisms. The lake has been the subject of intensive studies since the end of the 19th century. Here we demonstrate that between the 2003–07 and 2015–18 observation periods this permanently stratified lake experienced significant changes. The surface salinity increased and exceeded the tolerance limits of many freshwater organisms. The bottom anoxia expanded from onefifth to one-third of the lake volume. Such a turn in stratification affected both composition and distribution of biota: freshwater zooplanktonic species virtually disappeared, while benthic communities shifted to shallower depths. Although recent changes in the lake stratification are consistent with the longtermtrend, their scale is much larger than has been observed during the past 120 years. It was earlier considered that the lake dynamics were mainly affected by human activity in the vicinity of the lake. However, lack of human activity around Mogilnoe during last decades persuades us to search for the natural causes of the recorded changes.

AB - Lake Mogilnoe is a rare example of an anchialine lake (with subterranean connection to the ocean) in the Arctic, a refuge for landlocked populations of marine organisms. The lake has been the subject of intensive studies since the end of the 19th century. Here we demonstrate that between the 2003–07 and 2015–18 observation periods this permanently stratified lake experienced significant changes. The surface salinity increased and exceeded the tolerance limits of many freshwater organisms. The bottom anoxia expanded from onefifth to one-third of the lake volume. Such a turn in stratification affected both composition and distribution of biota: freshwater zooplanktonic species virtually disappeared, while benthic communities shifted to shallower depths. Although recent changes in the lake stratification are consistent with the longtermtrend, their scale is much larger than has been observed during the past 120 years. It was earlier considered that the lake dynamics were mainly affected by human activity in the vicinity of the lake. However, lack of human activity around Mogilnoe during last decades persuades us to search for the natural causes of the recorded changes.

KW - Arctic anchialine lake

KW - water stratification

KW - zoobenthos

KW - Zooplankton

KW - inter-annual changes

KW - conservation

U2 - http://dx.doi.org/10.33265/polar.v38.3394

DO - http://dx.doi.org/10.33265/polar.v38.3394

M3 - Article

VL - 38

JO - Polar Research

JF - Polar Research

SN - 0800-0395

M1 - 3394

ER -