Wave Energized Baltic Aeration Pump OXYGEN PUMPS. Powered by nature Imitating nature Restoring nature

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1 WEBAP Wave Energized Baltic Aeration Pump Picture: WEBAP pilot plant as tested in Hanöbukten OXYGEN PUMPS Powered by nature Imitating nature Restoring nature WHITE PAPER on artificial oxygenation of dead bottoms generated by the WEBAP project GUIDE for authorities and others on how we can use nature to restore marine environments before it is too late More information/contact PROJECT HOMEPAGE: PROJECT LEADER: Christian Baresel, With the contribution of the LIFE financial instrument of the European Community and the Foundation IVL.

2 Helping marine environments with help of nature itself Oxygen pumps: Powered by nature Imitating nature Restoring nature Oxygen depletion in marine environments of which the Baltic Sea is one of the most affected leads to severe problems not only for the ecosystems but indirectly also for society through adverse effects on tourism, health, fishery etcetera though algae blooming, disturbance of COD reproduction and others. Nature has shown that oxygenation of oxygen-depleted marine environments such as the Baltic Sea can help to restore balanced conditions that are required for a functional the ecosystems. The WEBAP project aimed at developing and testing pump technologies that could be applied to accomplish an resource-efficient oxygenation There are many opinions about oxygenation. The studies carried out within the project suggest that oxygenation through pumping down oxygen-rich surface water is not likely to break up stratification between surface and deep waters, something that often is used as an argument against actions. The measurements of different phosphorus fractions in sediments do not support the hypothesis that the reduced sediments in the Baltic represents a latent phosphorus bomb and the oxygenation of these would lead to the undesirable release of dissolved phosphorus. The results from the project indicates that it would be a step in the right direction to test oxygenation on a large-scale. The significance of the mineralization of organic carbon in the water column and in the sediment needs to be clarified before a forecast of how much pumping capacity would be required for different marine environments. Further, observations made in the project as well as other observations from the Baltic to suggest that oxygenation causes no increasing levels of environmentally harmful substances in the water. It is therefore unlikely that an oxygenation of the Baltic Sea would mobilize sediment -bound pollutants to such an extent that it would lead to adverse effects in the aquatic environment. Conducted life cycle and cost analysis indicates that oxygenation by oxygen pumps is one of the most energy - and cost-effective method compared to other techniques aiming to reduce the phosphorus content in the Baltic Sea. Of course these analyses can only provide a rough indication as they include assumptions made about the method s applicability and full-scale implementation. Based on the outcome of the WEBAP project it is recommended that one or both of the modular oxygen pumps developed by the project are applied in full-scale tests in a marine environment that facilitates long-term ecological impact studies of artificial oxygenation. To archive full integrity of oxygenation efforts activities aiming at minimizing the negative impact of society on the aquatic environment have to be supported and should be simultaneously implemented. This includes the further reduction of nutrients from municipal wastewater treatment but even more a more effective recycling of nutrients, improved management of decentralized wastewater treatment, and management of diffuse nutrient sources such as agriculture by applying relevant measures.

3 The problem: Eutrophication of our seas has many effects Society has put marine ecosystems under pressure. Especially wastewater effluent (treated and untreated), use of fertilizers in agriculture and other human impacts have destroyed the ecosystem in large areas of the Baltic Sea. The Swedish Institute for the Marine Environment, Havsmiljöinstitutet, reported in 2011: Oxygen conditions in the deep water of the Baltic sea is still very serious. The low oxygen levels recorded during the 2000s continues. Fully anoxic bottoms, under the influence of toxic hydrogen sulphide was found in one-sixth of the Baltic Proper. This represents approximately 10 percent of the water volume. North of Öland occurred during the fall of 2010 hydrogen sulphide already at water depths of 45 meters. Hydrogen sulphide in such a shallow depth has never been measured here before. Acute hypoxia (<2 mg oxygen per litre) was observed at 28 percent of the bottoms, representing one-fifth of the total water volume. The figure below shows the spread of anoxic bottom waters in the Baltic Sea in autumn Since then, the spread widened further and occupies in the current situation a volume that is considered as a maximum spread. Source: However, problems are observed all over the world as indicated in the figure to the right. The input of nutrients (nitrogen and phosphorous) to our seas causes algae blooming and the consumption of the oxygen in the deep water when the algae is decomposed. This in turn leads to a vicious circle of nutrient release from the sea sediments and more algae blooming. Besides the dead of the ecosystem and huge ecological and biological problems, tourism and fishery in coastal regions face large future economic problems.

4 Solution ideas and difficulties Even if nature has shown that oxygenation can restore oxygen-suffering marine environments, feasible, realistic and cost-effective solutions need to be developed to archive the reallocation of enormous amounts of resources. Nature has shown that oxygenation of dead bottoms improves the conditions in the deep-water layers of the Baltic Sea tremendously. By mixing water with oxygen-rich water from the North Sea, a decrease in phosphorus concentration in the water is observed in the Baltic Sea. Unfortunately, climate change will decrease such natural events as driving parameters change. To restore the Baltic Sea ecosystem and its self-cleaning processes before it is too late different actions are required. First, anthropogenic nutrient loads to the environment must be reduced because these are the main cause for dead bottoms. This may include: Increased efficiency in wastewater treatment at municipal sewage plants Functional decentralized sewage treatment, i.e. establishment of efficient wastewater treatment from households not connected to municipal sewage systems Increased recovery of nutrients from waste streams, e.g. sewage sludge Implementation of measures to reduce the nutrient loads from diffuse sources and others actions Second, the destroyed and suffering marine ecosystems of the Baltic Sea need some help to survive until the named actions above provide significant load reductions and to restore the ecosystems. For this, oxygenation is one of the most interesting approaches that have been discussed in recent years. However, the challenge is to provide in some way those million tons of oxygen that would be needed! For this, enormous amounts of pump energy would be needed because the depths were the oxygen is needed is up to metre deep. So the question is: Mission impossible?

5 WEBAP Wave Energized Baltic Aeration Pump Powered by Nature - Imitating Nature - Restoring Nature The basic WEBAP approach is simple; use of natural resources only to mimic a natural process in order to help to restore the Baltic Sea ecosystem. More specific this means: The sources of energy needed to pump oxygen to deep-water layers are waves or bio-energy. The source of oxygen provided to deep-water layers is oxygen-rich surface water. Advantages of the proposed approach are: The effect of oxygenation & mixing Simple and robust designs with long lifetimes

6 Developed oxygenation-pump systems Realistic and affordable technological solutions for various conditions. Different solutions for pumping at different scales and if waves are not sufficient (especially in archipelagos and close to shores) were developed. Some are already at full-scale while others have been tested in pilot-scale. 1) Wave powered pump for large-scale application at sea, maybe in combination with other offshore installations. Requires larger implementation schemes. 2) Biofuel-powered pump for coastal applications in the absence of wind or waves. Ready to implement system. 3) Wave powered pump for both inshore and offshore applications already at small waves. Ready to implement system.

7 Benefits Since using/imitating/supporting nature, the WEBAP approach has a direct positive environmental impact and generates environmental and socioeconomic benefits. The WEBAP project provides cost-effective technical solutions that may be used for the aeration of oxygen depleted dead bottoms to mitigate the problem of oxygen depletion ( hypoxia ) in the Baltic Sea. This would not only favourable effects on the ecosystem but an improved oxygen situation in the Baltic Sea would also have positive effects on tourism and the fishery. It is difficult to do something more environmentally friendly than using the power of nature to imitate nature. Environmental impact and total cost assessment indicates that the WEBAP approach is one of the most sustainable and cost-efficient alternatives. Further, the results and technologies of the project are (partly with modification) transferable to other marine environments in the world. The awareness about this severe environmental problem is just increasing.

8 What next? The project has generated enough information that would be needed to discuss and decide upon the next steps. It is thus time to agree on further actions that can study the artificial oxygenation of the Baltic Sea. Proposely that would have to be full-scale tests using one or both of the modular oxygen pumps developed by the project in a marine environment that facilitates long-term ecological impact studies of artificial oxygenation. However, full integrity of oxygenation efforts is only possible if other activities aiming at minimizing the negative impact of society on the aquatic environment are simultaneously implemented. OXYGEN PUMPS Powered by nature Imitating nature Restoring nature Collaboration partners