The fate of the Arctic spring bloom is well described. However, little is known about the fate of the autumn bloom the termination of the bloom and the winter situation that initiates the spring bloom. Therefore biomass estimations and respiration rates within boundary seasons are gap holes within the pelagic Arctic ecosystem.

To describe ocean – fjord – glacier interactions and the influence of predicted increased melting of the Greenland Ice Sheet it is crucial to have a boarder description of the variability in production and transfer efficiency through the lower food-web to higher trophic levels in a seasonal and spatial perspective.

Gelatinous plankton are likely to be favored due to predicted climate change due their broad physiological tolerance to changes in environmental conditions. However, their role and contribution to carbon cycling in arctic marine food webs is unknown but crucial to predict how anticipated changes in the Arctic will impact the community structure and productivity. We here suggest a combination of seasonal succession investigation of the community structure and experiments to test how environmental changes will impact on gelatinous plankton.

The copepod community structure has been shown do differ significantly in Godthåbsfjord compared to what is described in other Arctic areas. Abundances and biomasses have been described within the Marine Basic Nuuk monitoring program to be high during autumn and boundary seasons. Though respiration rates of the organismens is a gap hole where background data are needed in order to estimate the contribution of carbon turnover on an annual basis. The study will include rate measurements under laboratory controlled conditions.

Biomasses of krill will be estimated on a seasonal basis using a combination of acoustic surveys and net-haul based biomass estimations. Respiration- and grazing rates will be conducted under laboratory controlled conditions and used in combination with the biomass estimates in order to determine the contribution of carbon turnover on an annual basis

Site: sanna cruise in Godthåbsfjorden, Nuuk, Greenland

PI: Kristine Arendt