What are the effects of observed and predicted changes in Arctic sea ice extent, thickness, roughness, age (first-year ice (FYI) vs. multi-year ice (MYI)) and timing, on ecological processes operating across the ocean-sea ice-atmosphere (OSA) interface?
- Change from MYI to FYI will reduce ice fauna abundance and biomass, particularly of long-lived species (e.g. Gammarus wilkitzkii).
- Ridges in FYI will become the new biological hot spots when MYI has disappeared.
- Advection of more Atlantic water north of Svalbard will change the zooplankton communities from Arctic to more boreal (i.e. from Calanus glacialis to C. finmarchicus).
- Changes in sea ice (extent, thickness, freezing/melting) will affect zooplankton composition and life history aspects of major species in the ice-associated food web.
- Seasonal lipid accumulation will be reduced for zooplankton in ice-free waters, with consequences for lipid transfer to upper trophic levels (as fats and blubber).
- Polar cod will be limited to shelf and fjords in northern Svalbard when the ice retreats off-shore, and the ice-associated part of the population will be reduced.
- Energy stores of polar cod schools will be concentrated in fjords in northern Svalbard (e.g. Rijpfjorden) during autumn and winter (although the spawning part of the population will move out).
- Changes in sea ice and water masses will alter the food supply for the polar cod and thus affect its growth patterns (determined from otoliths).
- Changes in physical and biological factors during winter (spawning)-spring (food supply) will affect early growth and survival of polar cod and daubed shanny larvae (some of this will be determined experimentally).