The following themes are highlighted as examples of issues that are relevant for development of ecosystem-based management:
- Ocean acidification
- Mixed fisheries, undersized fish, discard of catches, bycatches and IUU fishing
- Impact of bottom trawling on benthos
- Risk of accidental discharges from oil and gas activities and ship transport
- Risk of introduction of alien species from ship traffic
- Long range transboundary pollution that is transported by air and water currents
- Risk of radioactive pollution
It should be emphasised that although this covers many of the most relevant themes, it should not be considered a complete list. Therefore, the highlighted themes should be looked upon as both a significant part of the basis for ecosystem based management in the Barents Sea as well as important examples that illustrate how the contents of this report may be used to further develop ecosystem-based management in the area. Some issues that are clearly relevant have not been discussed, such as the concept of vulnerable and valuable areas, which is important in the management plan for the Norwegian part of the Barents Sea. The need for specific attention to risks for the loss of biodiversity and needs for protective measures for threatened species of arctic endemics within the region are examples of other relevant issues that have not been discussed in the report.
The different themes described above may interact with each other. For example, if ocean acidification causes deteriorations of the food base of fish stocks, this can worsen the effect that any overfishing might have on these stocks. Similarly, if both acidification and bottom trawling affect benthic communities, their effects may be additive or even amplify each other. When developing holistic ecosystem-based management, an important challenge is therefore to conduct broad assessments of the combined impact of different types of human activities on the ecosystem.
For an ecosystem that is under considerable pressure from several anthropogenic drivers, it is particularly important to analyse whether their combined effects are so large that the ability of the system to absorb them may be exceeded, causing the ecosystem to shift into another stable state. Such changes have happened in several marine ecosystems, where collapses of cod stocks caused by overfishing, possibly exacerbated by climate variation, have triggered fundamental changes in the ecosystems that may not be possible to reverse. In the Barents Sea, impacts from climate change and ocean acidification are expected to increase in the future, while the level of fishing activities will remain high and increased oil and gas activities and ship transport are expected. To secure sustainable management of the area, it can therefore be helpful to perform the type of analyses described above that assess whether the combined impacts of all of these various anthropogenic drivers are likely to put the stability of the ecosystem at risk.
