Connecting climate signals with phytoplankton productivity and composition in a high Arctic fjord

• Main Author: van de Poll, Willem
• Format: Conference Object
• Language: English
• Published: 2016
• Subjects: Arctic; Kongsfjord*; Kongsfjorden; Phytoplankton; Polar Research; Spitsbergen
• Online Access: https://hdl.handle.net/11370/85da2896-9a0c-41bd-817e-45d38c9bf6eb; https://research.rug.nl/en/publications/85da2896-9a0c-41bd-817e-45d38c9bf6eb

Kongsfjorden is a high Arctic fjord on the West coast of Spitsbergen in a rapidly changing region that experiences both Arctic and sub-Arctic influences. This fjord has been subject to intense research since the 1980s. More recently, an effort was started by the AWI to collect daily physical, chemical and biological observations at a fixed site in Kongsfjorden (Under water Observatory). Since 2013, this includes weekly samples of phytoplankton pigments that are analyzed by the University of Groningen. The goal of this time series is to provide accurate observations on seasonal dynamics of phytoplankton biomass and composition. Continuation of this effort allows identification of trends on an inter-annual scale, linking phytoplankton boom magnitude and composition to influences of warm Atlantic (WSC) and Arctic (ESC) water masses. The first results of this time series are presented in concert with observations in Kongsfjorden during spring and summer of 2014 and 2015. In these campaigns we investigated physical/chemical environment and phytoplankton biomass and composition at two locations in Kongsfjorden (central Kongsfjorden and near the glaciers). In early spring these stations were different with respect to temperature, salinity, stratification, and light attenuation due to advection of Atlantic water. This resulted in differences in phytoplankton composition. These differences were minimal during the diatom dominated spring bloom that occurred after stratification by glacial melt water. Post bloom phytoplankton composition was more uniform between stations and was influenced by nutrient (N) limitation. The presented research is a first step in understanding the processes that govern phytoplankton biomass and composition in Kongsfjorden.