A fundamental challenge in developing IEAs that reliably inform EBM is to provide assessment tools that are process‐oriented and address whole ecosystem properties, such as biodiversity, that closely relate to ecosystem vulnerability. The above challenge will require an integration of information on demographic characteristics, ecological interactions and ecosystem functions of component species. Trait-based approaches and foodweb analysis can provide the required information, which, if properly

PCA – Abiotic variables

A Principal Component Analysis (PCA) for all abiotic variables, as listed in Table (Appendix 1), has been performed (Figure 2.2.1). Clearly, the analysis reveals that the two main drivers of variability of the Barents Sea climate system is the overall temperature (PC1; explaining 47% of the variability) and the through-flow of Atlantic Water (PC2; explaining 20% of the variability). The dynamic variability, i.e. changes in volume transports, are associated with changes in the North Atlantic Oscillation (NAO).

The Barents Sea is a heterogeneous system changing from boreal conditions in south-west to Arctic conditions in the north. To better reflect the changing conditions and trends over the large shelf and slope regions of the Barents Sea Large Marine Ecosystem (LME), we have subdivided the Barents Sea into twelve subareas shown in Figure 2.1.1 This division is a modified version of the system of subareas used in the analysis of spatial and temporal patterns of biomass of the pelagic compartment by Eriksen et al. (2017).