where did the oxygen go? working to save the baltic sea

Text and images by Rasmus Rodineliussen - 4th October 2019

 The Baltic Sea is a hub of transportation, fishing, and recreation. It is also “one of the most polluted Seas in the world” according to a marine scientist who I interviewed during my fieldwork in Sweden. My research examines the practical responses of different actors to climate change, marine pollution, and the quickly expanding environmental policy at UN, EU, and Swedish levels. This growth of environmental policy was especially evident following the launch of the UN Sustainable Development Goals with goal 14 explicitly addressing the concern of water, including work against increasing eutrophication, marine debris, and rising temperatures. Increased temperatures due to climate change is linked to eutrophication as a warmer climate means less ice and more rain, which results in more nutrients being moved from land to sea. Moreover, rising temperatures are also understood to increase algae growth – an issue I return to below.  

These tubes are evidence of human destruction of the marine environment. The lack of an oxidised brownish layer on top of the sediment indicates either very low or a total lack of oxygen at the bottom of the Baltic Sea. The lack of oxygen renders these sections of the sea effectively dead. These dead oxygen-starved areas are growing bigger and bigger.

How is the oxygen disappearing? A key theory is that fertilisers pollute the water leading to algal blooms. Algae produce oxygen during photosynthesis, but only when receiving sufficient light. The algae in the lower levels of water where there is less light actually consume oxygen. And dead algae also 'use' oxygen at the bottom through the process of decomposition. The researchers with whom I work are studying oxygen levels in the sediment layers as well as searching for signs of life in the form of macro and micro bacteria and organisms. Image 2 depicts a tray full of sediment that will be rinsed in search for macro organisms such as worms.

 Scandinavian countries are typically portrayed as forerunners in environmental management, and to some degree they are in relation to recycling and waste management. Yet the Baltic Sea is being drowned in fertilisers, plastics and other trash. There is a disconnect between the narrative of the eco-friendly north and the real state of the Baltic Sea.

There are many, rapidly growing social movements that battle marine pollution and climate change. I work with one such initiative: a group of scuba divers who remove plastics and other trash from the ocean to raise awareness about marine debris. The third image shows debris brought out of the Baltic Sea during a clean-up dive. These tyres would have slowly turned into micro plastics meanwhile leaking toxic chemicals into the water. Removing them is definitely beneficial but the tyres should not have been there to begin with.

As part of my research, I follow efforts by marine geologists to map (they use the term “paint”) the ocean floor to track geological changes over time. I conclude with a picture from a research vessel of a screen where the ocean floor is being painted – the scientists obtain a detailed map of the current configuration of the ocean floor that can be compared with earlier data to assess changes and patterns resulting from increased water levels. These paintings provide one type of data that then is combined with other types of data including sediment samples to gain a better picture of what is happening on the sea floor.

Rasmus Rodineliussen is a doctoral student at the department of social anthropology at Stockholm University. He is currently conducting fieldwork and will be doing so for about a year. Rasmus has earlier done work on refugees and migration with a special focus on Syria, and he is currently in the editorial team at Anthropology Book Forum