Marinbiologi

Isfauna

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?

Hypoteser:

  1. Change from MYI to FYI will reduce ice fauna abundance and biomass, particularly of long-lived species (e.g. Gammarus wilkitzkii).
  2. Ridges in FYI will become the new biological hot spots when MYI has disappeared.

Dyreplankton

Hypoteser:

  1. 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).
  2. 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.
  3. 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).

Polartorsk

Hypoteser:

  1. 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.
  2. 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).
  3. 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).
  4. 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).