Diving PM leads work for healthy oceans
The seas and coasts of much of the world are now ecologically unbalanced. Overfishing has often been cited as the dominant problem. But acidification, eutrophication, environmental plastics, pollution, and climate change are also important factors. The consequences are already significant – not least for people and our economy.
The High-Level Panel for Sustainable Ocean Economy was established in 2018 and is now chaired by Norwegian Social Democratic Prime Minister Jonas Gahr Støre. The panel consists of 14 member countries that together manage 45% of the world’s coastline. The countries have now committed to establishing sustainable management in 100% of their own marine and coastal areas by 2025. In other words, the first step is to put their own house in order. The panel points to the importance of seeing the ecology of the sea and the economy we harvest from it as two sides of the same coin. Other states are also invited to join the cooperation. Sweden is not yet a member.
Prime Minister Störe has presented the first major initiative at home: it wants to save the Oslo Fjord and commits to implementing a 100% sustainable management plan.
Oslofjorden – a holiday paradise…
For most Norwegians, the Oslo fjord has been synonymous with summer holidays, boating, swimming in fresh, clear sea water and perhaps the opportunity to catch your own dinner. Just a few decades ago, there were rich stocks of edible fish such as herring, cod, saithe, bleak and whiting. More unusual fish such as catfish, halibut, oysters, and tuna were also present. Porpoises also had permanent haunts in the fjord. Along the coasts, lush forests of seaweed and big tare grew, supporting a variety of small fish and crustaceans. In the last 40 years, the situation has changed radically and nowadays only small wrasse and wolffish remain in the often semi-cloudy waters. The once common cod has all but disappeared and the blue forest is shrinking dramatically.
What happened and who is to blame?
Until today, commercial fishing has been almost solely to blame for the state of the Oslo Fjord. Now, however, researchers are finding strong evidence that other factors are also involved – and perhaps just as important: the Oslo fjord region is Norway’s most populated area. A total of 1.6 million people, more than 30% of the country’s population, live here.
Norway is among the richest countries in the world and economic growth has been very rapid. But today we know that growth does not only mean prosperity. The problems are many: waste and emissions from households, pollution from transport and industry, fertilizers from agriculture and forestry carried by rivers into the Oslo Fjord. The result is what is called eutrophication. The input of nutrient salts is greater than what nature itself can handle. After a long, dark winter, the fjord is full of nitrogen-rich substances, and when spring light streams into the water masses, an almost explosive production of phytoplankton and zooplankton starts in the fjord’s surface waters. This surplus of organisms eventually dies and sinks to the bottom. Circulation in fjord bottom waters is generally low due to high sills formed in front of the glaciers – which once carved out the fjords. The sills impede the flow of water in and out of the fjord. The acid is quickly consumed as bacteria and small animals begin to break down the dead organisms. As in the Baltic Sea, oxygen deficiency causes the bottoms to become lifeless “deserts”.
Eutrophication has also been shown to have other consequences. The blue forests are being smothered by “turf” – a general cover of thin filamentous algae that benefit from the now increasingly nutrient-rich water. The turf attaches to the surface of the large algae, which are slowly suffocated by a lack of nutrient salts, carbon dioxide and light. As the “blue forest” is an important area for a myriad of life, and a “nursery” for a large number of food fish, this has major implications.
There is one more serious effect of fine filamentous algae. Like other forests, and all living things, the blue forest is built of carbon-rich substances. As the forest dies and eventually decomposes, huge amounts of carbon dioxide are released, helping to raise the Earth’s average temperature.
Professor Knut Rudi and his team at the Norwegian University of Agriculture are now working on an originally Swedish theory (*1), based on observations from the oxygen-poor bottoms of the Baltic Sea: oxygen deficiency and excess nutrient salts favors several fast-growing bacteria, over some slower-growing thiamine-producing bacteria that are very important for the ecosystem. Thiamine is the main component of vitamins B1 and B12 with absolutely vital functions in living beings. It is therefore feared that animals throughout the food chain could potentially suffer from vitamin deficiency. Professor Knut Rudi strongly believes in this theory and generally argues that a strategy to restore the Oslo Fjord should be based on all available knowledge in order not to “throw money at the problem”.
Science teaches us that all ecosystems are stabilized and therefore benefit from a high diversity of species. In an established and old ecosystem, none of the species has the opportunity to grow unchecked. In simple terms, if a species increases in number in one period, this favors the predator of the species, which in the next round limits growth. Species limit and protect each other in their mutual competition for resources. Moreover, nature is so ingeniously designed that the waste products of animals are the food of plants. Supply and demand for vital substances are constantly balanced. This is essentially the interplay of nature we call, in a finer word, ecology.
Because we humans are at the top of the ecosystem and, unlike other species, are constantly finding new strategies and developing new technologies to grab more, we have a totally dominant role in the various food webs. It is fair to say that humans have become too “good” to fit in with all the plant and animal species. They are bound by traits that can only be changed very slowly and from an evolutionary perspective. In our short-sightedness and zeal, we easily forget that what we are striving for, prosperity and economic balance, is always based on ecological balance. But how will Norway’s prime minister manage to establish sustainable management in the Oslo Fjord, even by 2025?
The measures to save the Oslo Fjord.
In 2019, the previous Norwegian government introduced a total ban on cod fishing within a baseline that runs from northern Norway to the Swedish border at Strömstad. All sport fishing, fishing with bottom nets and fishing within known cod spawning areas was then completely banned. As cod and seals are believed to compete for the same food, the harvest of harp seals in the Oslo Fjord has also been increased by 30%. However, it has become clear that these measures are not enough.
The decision to stop fishing in the Oslo Fjord was perhaps not so difficult to take, as there were no fish to catch. But the measure took too long: the authorities said they wanted to protect jobs for a few fishermen.
According to the action plan launched by Støre and his Social Democratic government, all excess nutrient salts need to be removed. Emissions from agriculture and households will probably be the most important measure, but also the most difficult. Agriculture has become totally dependent on artificial fertilizers, and fields are densely packed along Norway’s most water-rich river, the Glomma. Rainwater carries the fertilizer into the river, which flows into the outer Oslo fjord. There, a northward flowing sea current takes over and carries the nutrient-rich water into the fjord. Norwegian forestry is also at its most intensive in the Glomma catchment area. Today’s Norwegian forestry is just as industrialized and unsustainable as in Sweden. Monocultures of spruce and pine are planned on large clearings where thousands of years of accumulated humus are exposed. The method has been shown to release nutrient salts that leach into nearby waterways and eventually end up in the Oslofjord.
Støre and the government will set stricter requirements for the discharge of municipal wastewater. It will require that all nitrogen must be removed. If the Oslo fjord is to recover, major efforts will be needed.
Prime Minister Støre recalls that in the 1970s Norway narrowly avoided losing the spring-spawning herring. This was a very costly lesson for Norway. The overfishing was massive and thanks to some scientists warning of what was happening, the stock slowly recovered. Norway was given a second chance to establish sustainable management.
Støre stresses that there is a risk that fish stocks cannot recover. The huge cod stocks off Newfoundland were fished out in the 1980s and have not come back. Støre notes how important it is not to manage species separately, but to look at the whole ecosystem. You must introduce what is now called ecosystem-based management.
In an interview with NRK, Prime Minister Støre underlines the international panel’s goal: to stop all harmful emissions into the sea. He plans to involve the whole world in the work over the next two years. One of the goals is to get a global legally binding agreement against plastic pollution. The goal is for it to be signed during the 2024 UN Environment Summit.
*1 Balk, L., Hägerroth, PÅ., Gustavsson, H. et al. Widespread episodic thiamine deficiency in Northern Hemisphere wildlife. Sci Rep 6, 38821 (2016). https://doi.org/10.1038/srep38821