It is already evident that climate change is altering marine ecosystems. Further effects of warming seas are likely to become visible in the future, with fish populations and breeding grounds relocating and new species taking their place.
One consequence of rising global temperatures is the melting of ice in Greenland and the Antarctic, which could lead both to rising sea levels and changes in ocean currents. That in turn will affect the lives of marine organisms.
Absorbing emissions
Before human (anthropogenic) activity altered the carbon cycle, the quantity of CO2 added to the atmosphere from terrestrial and marine fauna and flora was balanced by the amount extracted by photosynthesis and storage in reservoirs on land and offshore.
Since the Industrial Revolution began in the 18th century, consumption of coal, oil and gas has increased the amount of CO2 in the atmosphere. The content of this greenhouse gas (GHG) has risen by almost 40 per cent and is growing year by year.
The oceans currently absorb about a quarter of anthropogenic carbon emissions, but new research shows that such uptake in the North Atlantic and the Southern Ocean has weakened over recent decades.
Acidification
Dissolving CO2 in seawater produces carbonic acid, which reduces the pH value of the oceans and thereby makes them more acidic.
The acidity of the world’s seas has increased by 26 per cent since the Industrial Revolution began, and this process is gathering speed – particularly in areas close to the Poles.
That represents the fastest change to the marine environment ever witnessed. Norwegian waters are particularly subject to acidification, particularly in the far north.
That is because cold water can absorb more CO2 than warmer seas, and because fresh water from rivers and melting ice weaken the ocean’s ability to neutralise the acid build-up.
Go here to find material on ocean acidification (in Norwegian).
Big threat
Acidification of the sea is one of the biggest threats to marine life, but attention has only turned to the consequences of this process in recent years. Research in the field is therefore relatively new.
Rising ocean acidity reduces the availability of calcium carbonate, creating problems for animals which depend on this substance to build shells or bones. Plankton species, prawns, lobsters, snails, mussels, starfish, sea urchins and corals are among those affected.
While increasingly acid seas look like becoming a substantial problem, they probably acts as a contributory factor in combination with other physical conditions.
Influences such climate change and rising pollution could worsen the position even further. A substantial research effort is required in this area.
New toxins pose challenges
Environmental toxins can affect marine life in many ways, which include causing foetal deformities and reducing reproductive ability.
While some of these substances have been banned, a large number of new toxins are being introduced without enough being known about their effects.
The greater attention being paid to the climate threat and to enhancing energy efficiency has resulted in research on and development of new technologies and products.
Examples of these include new construction materials, increased use of wood preservatives, surface treatment chemicals and energy-saving lightbulbs.
Securing sufficient information about the environmental consequences of these new substances and products will be important.
Big wind power potential
Government policy in Norway and elsewhere assigns an important place to expanding the use of renewable energy in order to reduce global GHG emissions.
Wind power has been the fastest-growing renewable source in Europe during recent years, and Norway is among the European countries with the best potential for this form of energy.
That reflects its extensive seas with good wind conditions. Wind power accounted for 1.7 per cent of total Norwegian electricity generation in 2015.
The Norwegian Water Resources and Energy Directorate (NVE) has mapped the country’s exploitable wind power resources, and also publishes annual reports on the status and output of existing wind farms.
Harnessing wind power is expected to continue expanding in coming years as part of meeting Norway’s climate targets for 2020. The relevant technology has advanced, with a steep learning curve.
Read more about wind power (in Norwegian only) at the NVE.
Avoiding conflicts
Offshore wind farms need to be located in areas where conflicts with other environmental considerations and user interests – such as shipping, fishing and petroleum – are at an acceptable level.
Norway’s Energy Act applies to offshore wind farms developed within the baseline – an imaginary boundary drawn between the outermost islands and rocks along the Norwegian coasts.
Facilities which are installed outside this baseline have been covered by the Act on Renewable Energy Production at Sea adopted in 2010. Find the Act here (in Norwegian only).
Read more about offshore wind power here (in Norwegian only).
Fishing and aquaculture
Overfishing and illegal catches can have dramatic consequences for fishing stocks and the ecosystem as a whole. That makes it important to set clear ceilings for exploitation in line with research, and to give overfished populations space to recover.
Fish farming is steadily expanding in Norway. Escaped farmed fish, high levels of nutrients and diseases such as salmon (sea) lice pose threats to many vulnerable species and populations.
Industry and leisure
Both industrial and leisure activities are expected to increase along the Norwegian coast. In addition to fishing and aquaculture, freight transport, tanker shipping and petroleum are among important industrial operations set to expand.
All in all, the overall burden on the sea will grow. Good planning is needed, not least to ensure that the various activities can share the marine space without conflicts.
The management plans for Norway’s sea areas and the EU’s water framework directive are among the measures which will contribute to this.
Plastics worst
The Norwegian Environment Agency (NEA) calculates that plastics account for roughly 75 per cent of total marine waste. This is because these substances take a long time to degrade in the sea.
All plastics break down over time into tiny fragments known as microplastic. These also derive from cosmetics, other care products and the laundering of plastic-based textiles.
This waste is carried by ocean currents across national boundaries. Chemicals dissolved from it include environmental toxins which stick to microplastic as it floats around.
Both plastics and chemicals can harm fauna above and below the surface. Zooplankton and other species low down the food chain are at particular risk.
Seabirds are also very vulnerable to plastics because they mistake small pieces of such waste for food.
One defence against these problems is the Oslo-Paris convention for the protection of the marine environment of the north-east Atlantic (Ospar). An action plan to combat marine pollution was adopted in 2014.
Read the NEA’s article on microplastics choking marine life(outdated).
Improved monitoring
Very few methods are currently available for monitoring life in the open ocean, although much research is under way to remedy this position.
Particular difficulties are faced in establishing the impact of pollution, and especially the interrelated effects of several sources in combination with climate changes.
More coordinated cross-national efforts are needed to achieve a monitoring and follow-up which can support ecosystem-based management. It is important that such surveillance is adapted to new challenges such as global warming and ocean acidification.
Marine management
National work on management plans for all Norway’s offshore areas and on the water regulation in watercourses and the coastal zone, as well as international efforts, mean greater attention and commitment are being directed at the marine environment.
This will contribute to improved protection for the areas of the North, Norwegian and Barents Seas under Norwegian jurisdiction, their ecosystems and their resources.
