Monitoring on the marine environment and phytoplankton of Kongsfjorden, Svalbard, Arctic

Abstract

Kongsfjorden near Korean Arctic Station, Dasan, is a glacial fjord in the Svalbard archipelago, Arctic that is influenced by both Atlantic and Arctic water masses. During the Arctic field season, August 2002, surface temperature, salinity, density, and phytoplankton biomass (chl a) was measured in Kongsfjorden. A total of 15 surface samples were collected for the phytoplankton related measurements. Chl a values ranged from 0.08 to 1.4 mg chl a m-3 (mean of 0.53 mg chl a m-3) in the overall surface stations. The highest values of the chl a concentrations (> 1.0 mg chl a m-3) were found near glacier in the northeastern part of Kongsfjorden. Nanoplanktonic (< 20 μm) phytoflagellates were important contributors for the increase of the chl a. The nano-sized phytoflagellates accounted for more than 90% of the total chl a biomass in the study area. Surface temperatures and salinities ranged from 2.5 to 7.18°C (mean of 4.65°C) and from 22.55 to 32.97 psu (mean of 30.16 psu), respectively. The physical factors were not highly correlated with phytoplankton distribution. The character of surface water due to down-fjord wind was highly similar to phytoplankton distribution. Drifting ice, freshwater, and semdiment inputs from large tidal glaciers located in the inner part of Konsfjorden create steep physico- and biogeochemical environmental gradients along the length of this fjord. The glacial inputs cause reduced biodiversity, biomass, and productivity in the pelagic community in the inner fjord. Primary production of benthic and pelagic microalgae is reduced due to the limited light levels in the turbid and mixed inner waters. The magnitude of glacial effects diminishes towards the outer fjord. Kongsfjorden is an important feeding ground for marine mammals and seabirds. Especially, seabirds play the largest energy intake and also export nutrients for primary production of the marine microalgae. Kongsfjorden has received a lot of research attention as a site for exploring the impacts of climate changes. Dasan Station in Kongsfjorden will be an important Arctic site for monitoring and detecting future environmental changes.