Features of the Distribution of Chlorophyll-a Concentration along the Western Coast of the Novaya Zemlya Archipelago in Spring

Abstract

In spring 2016, the thermohaline characteristics of water masses and the distribution of chlorophyll-a concentration in the pelagic zone of the eastern part of the Barents Sea were studied. For the first time, in the conditions of an abnormally warm year and the absence of ice cover, a complex of hydrobiological works was carried out on a section crossing the Barents Sea from south to north along the western coast of the Novaya Zemlya archipelago. High concentrations of chlorophyll-a > 1 ˂ 6 mg/m3 at all stations of the transect indicate a stage of spring bloom in the successional cycle of microalgae. Significant differences in the content of chlorophyll-a in waters of various origins were revealed. The highest concentrations of chlorophyll-a corresponded to Arctic surface water (5.56 mg/m3). Slightly lower values were observed in the transformed Atlantic waters of the Novozemelskoe and Kolguevo–Pechorskoe currents (3.53 ± 0.97–3.71 ± 1.04 mg/m3), and the lowest was in the Barents waters (1.24 ± 0.84–1.45 ± 1.13 mg/m3).

Coastal Mesozooplankton Assemblages during Spring Bloom in the Eastern Barents Sea

“…The chlorophyll a concentration in the surface layer at the southern part of the transect (stations 1 and 2) was generally > 2.5 mg m −3 . Surface concentrations from 1.1 to 1.9 mg m −3 were found at stations 3 and 4 [ 24 ]. Maximum chlorophyll a concentrations (4.0–4.6 mg m −3 ) were recorded in the surface layer in the central part of the transect (stations 5 and 6).…”

“…High chlorophyll a concentration (2.4 mg m −3 ) was also found at station 7. Surface chlorophyll a concentration decreased north of this location, with the minimum value (0.21 mg m −3 ) at station 9 [ 24 ]. The northernmost station was characterized by higher chlorophyll a concentration (2.1 mg m −3 ).…”

“…The filters were kept frozen until analysis in a hydrochemical laboratory. The filters were subsequently extracted in 90% acetone, placed in a freezer at 4 °C for 24 h, and chlorophyll a concentrations were measured using a Nicolett Evolution 500 spectrophotometer (Spectronic Unicam, Cambridge, UK) which had been calibrated with commercially purified chlorophyll a preparations [ 24 ].…”

“…In nutrient-poor, high-latitude cold waters, it is usually the single seasonal peak of primary production, providing the energy and matter base for zooplankton and nekton production [ 8 ]. The spring phytoplankton bloom is the key determinant of the flow of carbon through the marine food web, and, therefore, this seasonal phase is the most important event in primary production in Arctic environment [ 22 , 23 , 24 ]. In the Barents Sea, the initial spring blooms in AW, CW and the marginal ice zone are usually dominated by diatoms [ 25 ].…”

“…Peaks of phytoplankton are registered in May–June when there is clear water stratification in most regions of the Barents Sea. During this period, the phytoplankton abundance tends to rise more rapidly in Polar than in Atlantic Waters [ 6 , 8 , 24 ]. The decline in phytoplankton abundance is in June–July because of rapid nutrient depletion.…”