Diatom and Dinocyst Production, Composition and Flux from the Annual Cycle Sediment Trap Study in the Barents Sea

Abstract

This paper presents the diatom and palynomorph data from a sediment trap deployed in the northern part of the East Barents Sea for an annual cycle from August 2017 to August 2018. The average monthly fluxes of diatoms and dinoflagellate cysts in the photic layer of the northeastern part of the Barents Sea varies from 10.4 × 103 to 640.8 × 103 valves m−2 day−1 and from 0.3 × 103 to 90.0 × 103 cysts m−2 day−1, respectively. Their fluxes are related to the low irradiance of the photic layer during the sea-ice cover period, dominance of southward currents, modern climate, and nepheloid layer conditions. Based on redundancy analysis of the relationship between the fluxes of diatoms and dinoflagellate cysts and organic carbon fluxes, sea-ice covers, and the seasonal cycle of light availability we determined the following. First, sea-ice-associated diatoms and dinocysts are exported to the sediment trap from the melting sea ice with a two-week delay. Second, the appearance of freshwater diatoms and green algae in the sinking material accumulating from March 2018 to July 2018 is also related to the melting of sea ice. And third, the presence of Coscinodiscus radiatus, C. perforatus, Shionodiscus oestrupii and Operculodinium centrocarpum in the diatoms and dinocysts species composition throughout the year indicates the advection of Atlantic waters into the Barents Sea up to 80° N.

Average annual flux of organic carbon to the bottom in the arctic seas of Russia: a comparison of calculated and research instrument data from sediment traps

“…Particulate organic carbon is 40-90% deposited in estuarine zones and on the adjacent shelf, constituting the major part of the organic carbon flux to the bottom, which is confirmed by our long-term studies using sedimentation traps in the White and Barents Seas 12,16 (Fig. 1).…”

“…The flux of organic carbon to the bottom is calculated using the empirical relationship Fc = 33 PP/Z, where PP is the value of primary production in the water column and Z is the depth 2 . *novigatsky@ocean.ru; phone (499) 124-77-37; www.ocean.ru Studies of the fluxes of lithogenic and biogenic particles using long-term (more than a year) sedimentation traps in the northern high latitudes are still very rare and limited to the Arctic marginal seas and subarctic regions [12][13][14][15][16][17][18] . The method of sedimentation traps [19][20] makes it possible to determine benthic vertical fluxes (mgC/m 2 /day) of suspended particulate organic carbon (С bio ) quite confidently, despite some uncertainties in the form of active benthic hydrodynamics, nepheloid layers, daily migration of zooplankton, etc.…”

Holocene Sedimentation History of the Knipovich Ridge Area (The Norwegian Sea) Based on the Analysis of Microfossils

“…Таяние льда могло способствовать поступлению ледово-морских видов диатомей во время их вегетации в прикромочной зоне льдов в осадочное вещество и дальнейшему их сохранению в отложениях. Это подтверждается недавними исследованиями состава диатомовых ассоциаций осадочного вещества в северо-восточной части Баренцева моря [Agafonova et al, 2023] и осадочного вещества, льда и поверхностных отложений одного из фьордов северо-восточной Гренландии [Limoges et al, 2018]. Результаты этих работ показали, что ледово-морские диатомеи поступают в осадочное вещество и поверхностные осадки во время и по-сле таяния сезонного морского льда [Limoges et al, 2018;Agafonova et al, 2023].…”