Algal pigments in Hornsund (Svalbard) sediments as biomarkers of Arctic productivity and environmental conditions

Abstract

Pigments (chloropigments-a and carotenoids) in sediments and macroalgae samples, collected in Hornsund, in July 2015 and July 2016, were analysed (HPLC) in this work. In spite of the aerobic conditions and the periodic intensive solar irradiation in the Arctic environment, neither of which favour pigment preservation in water column and surface sediments, our results indicate that these compounds can provide information about phytoplankton composition, primary production and environmental conditions in this region. The sum of chloropigments-a, a marker of primary production, in the Hornsund sediments varied from 0.40 to 14.97 nmol/g d.w., while the sum of carotenoids ranged from 0.58 to 8.08 nmol/g d.w. Pheophorbides-a and pyropheophorbides-a made up the highest percentage in the sum of chloropigments-a in these sediments, supplying evidence for intensive zooplankton and/or zoobenthos grazing. Among the carotenoids, fucoxanthin and its derivatives (19'-hexanoyloxyfucoxanthin and 19'-hexanoyloxy-4-ketofucoxanthin) contributed the highest percentage, which points to the occurrence mainly of diatoms and/or haptophytes in the water. The pigment markers show that the input of macroalgae to the total biomass could be considerable only in the intertidal zone.

Reproductive traits and population dynamics of benthic invertebrates indicate episodic recruitment patterns across an Arctic polar front

“…Here, evidence from the pyloric caeca index at and north of the polar front suggests that a higher quantity and/ or quality of food has been available to the populations recently under the edge of the ice margin, and subsequently stored excess energy (McClintock, 1989). This corresponds to the higher total organic carbon content of the sediment, which is mostly derived from ice algae within the region of study (Stevenson and Abbott, 2019), and evidence of increasing chlorophyll a found in sediments north of the polar front (Krajewska et al, 2017;Morata and Renaud, 2008).…”

Algal Community Change in Mountain Lakes of the Alps Reveals Effects of Climate Warming and Shifting Treelines1

“…The fact that other studies already detected D+D (Repeta 1989, Brotas and Plante‐Cuny 2003, Krajeswka et al. 2017) and prasinoxanthin in sediments (Sampere et al. 2011, Kang et al.…”

Editorial: Biogeochemical Consequences of Climate-Driven Changes in the Arctic

“…Increased discharge of freshwater (McClelland et al, 2006) and terrestrial organic matter into Arctic coastal water (Parmentier et al, 2017) further influence the timing of natural cycles. The ecological consequences of these changes manifest in adjusted primary productivity cycles (Lewis et al, 2020), alterations in the quality and quantity of organic matter reaching the seafloor (Krajewska et al, 2017;Stevenson and Abbott 2019;Olivier et al, 2020), benthic biogeochemical cycles (MacDonald et al, 2015;Solan et al, 2020) and the food-web (Yunda-Guarin et al, 2020). Mechanistic understanding of these processes requires continual revision, and in this research topic, we report new findings and emerging insights about how Arctic biogeochemical processes are responding to climate change and altering system dynamics.…”