Cleaning up seas using blue growth initiatives : Mussel farming for eutrophication control in the Baltic Sea

Eutrophication is a serious threat to aquatic ecosystems globally with pronounced negative effects in the Baltic and other semi-enclosed estuaries and regional seas, where algal growth associated with excess nutrients causes widespread oxygen free “dead zones” and other threats to sustainability. Decades of policy initiatives to reduce external (land-based and atmospheric) nutrient loads have so far failed to control Baltic Sea eutrophication, which is compounded by significant internal release of legacy phosphorus (P) and biological nitrogen (N) fixation. Farming and harvesting of the native mussel species (Mytilus edulis/trossulus) is a promising internal measure for eutrophication control in the brackish Baltic Sea. Mussels from the more saline outer Baltic had higher N and P content than those from either the inner or central Baltic. Despite their relatively low nutrient content, harvesting farmed mussels from the central Baltic can be a cost-effective complement to land-based measures needed to reach eutrophication status targets and is an important contributor to circularity. Cost effectiveness of nutrient removal is more dependent on farm type than mussel nutrient content, suggesting the need for additional development of farm technology. Furthermore, current regulations are not sufficiently conducive to implementation of internal measures, and may constitute a bottleneck for reaching eutrophication status targets in the Baltic Sea and elsewhere. Highlights • Mussel farming is a viable internal measure to address Baltic Sea eutrophication. • Rates of nutrient removal depend on salinity at the regional scale and food availability at the local scale. • Cost effectiveness of nutrient removal by mussel farming depends also on farm type. • Total farm area needed for achieving HELCOM nutrient reduction targets is realistic

Aquakultur und Klimawandel in der Ostsee

Der Bericht geht der Frage nach, wie sich Klimaveränderungen auf die Perspektiven für Aquakulturen in der Ostsee auswirken könnten. Von besonderer Bedeutung sind hier die Aspekte Temperaturzunahme, Meeresspiegelanstieg, Versauerung sowie der Salzgehalt des Meerwassers. In dem Bericht wird untersucht, was die erwarteten Veränderungen für derzeit kultivierte Algen-, Fisch- und Muschelarten bedeuten und welche Arten in Zukunft kultiviert werden könnten. Zum Abschluss des Berichtes wird das Konzept einer nachhaltigen, klimaangepassten Aquakultur vorgestellt, wie es teilweise in der Kieler Förde bereits verwirklicht wurde

Hybride Formen urbaner Produktion durch Digitalisierung? Trends und Beispiele aus Nordrhein-Westfalen

Dieser Beitrag knüpft an aktuelle Diskurse zu Digitalisierungsprozessen und Raumentwicklung an. Es wird untersucht, inwiefern durch digitalisierte Fertigungsmethoden (wie Industrie-4.0-Anwendungen) neue Formen urbaner Produktion entstehen können. Aufbauend auf theoretisch-konzeptionellen Überlegungen wurden empirische Erkenntnisse durch 41 Experteninterviews in acht industriell geprägten Städten Nordrhein-Westfalens gewonnen. Die Ergebnisse zeigen, dass durch die gewerbliche Anwendung neuer digitaler Fertigungsverfahren neuartige Formen hybrider digitaler urbaner Produktion entstehen, die spezifischen problemzentrierten Wertschöpfungslogiken unterliegen. Der Beitrag entwickelt ein präziseres Verständnis dieser Wertschöpfungsprozesse und der Standorteinbettung hybrider digitaler urbaner Produktion.Building on current debates on digitalisation and spatial development processes, this paper aims to explore to what extent digitally enhanced production technologies, such as Industry 4.0, enable the emergence of new forms of urban production. Based on theoretical and conceptual considerations, empirical insights are derived from 41 interviews conducted with experts in eight industrial cities in the German state of North Rhine-Westphalia. The results indicate that the commercial application of new digital production technologies instigates novel forms of hybrid digital urban manufacturing which change patterns of previous value creation. The paper develops a more precise understanding of these value creation processes and the locational embeddedness of hybrid digital urban manufacturing

Stepping stones along urban coastlines-improving habitat connectivity for aquatic fauna with constructed floating wetlands

Urban development along coastlines is accompanied by habitat fragmentation and loss of habitat connectivity, particularly affecting the habitat and nursery function of estuarine areas for migratory marine species. Constructed floating wetlands, deployed as ‘stepping stones’ along urban coastlines where natural wetlands are missing, offer the potential to partially replace lost ecosystem services. Originally developed for wastewater treatment, constructed floating wetlands are now used to improve landscape aesthetics or create habitats for aquatic fauna and birds. This study presents a toolkit to identify appropriate sites for stepping stones using open source data and open source software alone. The toolkit was used to identify 85 potential installation sites along the German Baltic Sea coast, a large proportion of which are located in protected areas offering synergies with nature conservation measures. Though the sites are often located in protected areas, the field investigation revealed that natural vegetation is largely absent from the estuaries near urban areas. Constructed floating wetlands can never replace ‘core areas’ in ecological networks, but they can serve as stepping stones improving habitat connectivity, especially for diadromous fish species such as the threatened European eel. To ensure not only structural connectivity, but also functional connectivity, restoration efforts at the land-sea interface must be holistic and include adequate hydrologic connectivity

Reallabor Eckernförder Bucht 2030 – the first living lab covering sea, coast and land

1. The living lab method (German: “Reallabor”) is a proven tool from sustainability research. Although it offers a lot of potential for application to complex challenges in marine conservation, it has scarcely been used in this context so far. 2. This article presents the project "Reallabor Eckernförder Bucht 2030", which is the first living lab addressing the areas of sea, coast and land together. 3. The project was developed in co-design between science, ministries and other stakeholders. 4. It was possible to show that the Living lab method is suitable for a multi-stakeholder dialogue with many interlinked challenges, e.g. agriculture, fisheries, nature protection and tourism. 5. Synthesis and applications: The living lab method is suitable for addressing complex challenges addressing the areas of sea, coast and land together in a geographically limited space. A cooperation between science, society and administration helps to tackle environmental problems by identifying solutions that a) have a high societal acceptance, b) are based on interdisciplinary scientific knowledge, and c) fulfil administrative rules and conditions. The "Reallabor Eckernförder Bucht 2030" serves as a blueprint for projects also on international level