Person of interest
storageTemp: neg 80 C
This PhD project aims to investigate nutritional variations and selective feeding of Arctic and sub- Arctic plankton consumers along latitudinal gradients in dierent seasons as part of the Nansen Legacy project focusing on comprehensive studies of the Barents Sea ecosystems in the context of ongoing climate change. The main focus will be placed on the primary producer-consumer link of lower trophic plankton communities in the Barents Sea and adjacent Arctic Ocean. By means of dilution and/or grazer exclusion experiments, eects of food quantity and quality on growth and nutritional composition of consumers will be investigated as well as selective grazing and food web structures using natural plankton communities. As main grazers in the microbial loop, microzooplankton (20-200 m) represent an important intermediate link between primary producers and secondary consumers such as mesozooplankton and sh larvae. The capacities of micrograzers to buer nutritional imbalances at the primary producerconsumer interface (trophic upgrading) will be considered. Mesozooplankton (0.2 mm-2 cm) in turn represents an important food source for higher trophic levels such as early life stages of sh and planktivorous shes. Changes in the quantities and nutritional quality at lower trophic levels may have consequences for higher trophic ones. Arctic-inuenced regions of the Barents Sea dier fundamentally from Atlantic-inuenced ones. Experiments along a south-to-north gradient will help to quantify the structure and function of the poorly described northern ecosystem in contrast to central and southern ecosystems. The results will help to understand the dynamics between primary producers and consumers as well as the overall energy transfer eciencies in marine food webs. This knowledge can be used to improve future projections and management concepts for the ecosystem of the Barents Sea in particular and other transitional polar regions in general.