Along the German North Sea coast, the observed high spatial competition of stakeholders has encouraged the idea of integrating open ocean aquaculture in conjunction with oVshore wind farms beyond the 12 miles zone. The article provides an overview on the current state of transdisciplinary research on a potential implementation of such a multifunctional use concept on a showcase basis, covering biological, technical, economic and social/policy aspects as well as private-public partnerships and the relevant institutional bodies. We show that the cultivation of seaweeds and blue mussels is biologically and technically feasible in a high-energy environment using modiWed cultivation strategies. The point of departure of our multi-use concept was that the solid groundings of wind turbines could serve as attachment points for the aquaculture installations and become the key to the successful commercial cultivation of any oVshore aquatic organism. However, spaces in between the turbines are also attractive for farming projects, since public access is restricted and thus the cultivation site protected from outside inXuences. An economic analysis of diVerent operation scenarios indicates that the market price and the annual settlement success of juvenile mussels are the main factors that determine the breakeven point. Social and policy science research reveals that the integration of relevant actors into the development of a multi-use concept for a wind farm-mariculture interaction is a complex and controversial issue. Combining knowledge and experience of wind farm planners as well as mussel Wshermen and mariculturists within the framework of national and EU policies is probably the most important component for designing and developing an eVective oVshore co-management regime to limit the consumption of ocean space.

Marine processes are observed with sensors from both the ground and space over large spatio-temporal scales. Citizen-based contributions can fill observational gaps and increase environmental stewardship amongst the public. For this purpose, tools and methods for citizen science need to (1) complement existing datasets; and (2) be affordable, while appealing to different user and developer groups. In this article, tools and methods developed in the 7th Framework Programme of European Union (EU FP 7) funded project Citclops (citizens' observatories for coast and ocean optical monitoring) are reviewed. Tools range from a stand-alone smartphone app to devices with Arduino and 3-D printing, and hence are attractive to a diversity of users; from the general public to more specified maker-and open labware movements. Standardization to common water quality parameters and methods allows long-term storage in regular marine data repositories, such as SeaDataNet and EMODnet, thereby providing open data access. Due to the given intercomparability to existing remote sensing datasets, these tools are ready to complement the marine datapool. In the future, such combined satellite and citizen observations may set measurements by the engaged public in a larger context and hence increase their individual meaning. In a wider sense, a synoptic use can support research, management authorities, and societies at large.

Abstract. Marine environments are influenced by a wide diversity of anthropogenic and natural substances and organisms that may have adverse effects on human health and ecosystems. Real-time measurements of pollutants, toxins, and pathogens across a range of spatial scales are required to adequately monitor these hazards, manage the consequences, and to understand the processes governing their magnitude and distribution. Significant technological advancements have been made in recent years for the detection and analysis of such marine hazards. In particular, sensors deployed on a variety of mobile and fixed-point observing platforms provide a valuable means to assess hazards. In this review, we present state-of-the-art of sensor technology for the detection of harmful substances and organisms in the ocean. Sensors are classified by their adaptability to various platforms, addressing large, intermediate, or small areal scales. Current gaps and future demands are identified with an indication of the urgent need for new sensors to detect marine hazards at all scales in autonomous real-time mode. Progress in sensor technology is expected to depend on the development of small-scale sensor technologies with a high sensitivity and specificity towards target analytes or organisms. However, deployable systems must comply with platform requirements as these interconnect the three areal scales. Future developments will include the integration of existing methods into complex and operational sensing systems for a comprehensive strategy for long-term monitoring.Correspondence to: O. Zielinski (oliver.zielinski@imare.de)The combination of sensor techniques on all scales will remain crucial for the demand of large spatial and temporal coverage.

Abstract. Marine environments are influenced by a wide diversity of anthropogenic and natural substances and organisms that may have adverse effects on human health and ecosystems. Real-time measurements of pollutants, toxins, and pathogens across a range of spatial scales are required to adequately monitor these hazards, manage the consequences, and to understand the processes governing their magnitude and distribution. Significant technological advancements have been made in recent years for the detection and analysis of such marine hazards. In particular, sensors deployed on a variety of mobile and fixed-point observing platforms provide a valuable means to assess hazards. In this review, we present state-of-the-art of sensor technology for the detection of harmful substances and organisms in the ocean. Sensors are classified by their adaptability to various platforms, addressing large, intermediate, or small areal scales. Current gaps and future demands are identified with an indication of the urgent need for new sensors to detect marine hazards at all scales in autonomous real-time mode. Progress in sensor technology is expected to depend on the development of small-scale sensor technologies with a high sensitivity and specificity towards target analytes or organisms. However, deployable systems must comply with platform requirements as these interconnect the three areal scales. Future developments will include the integration of existing methods into complex and operational sensing systems for a comprehensive strategy for long-term monitoring. The combination of sensor techniques on all scales will remain crucial for the demand of large spatial and temporal coverage.