Description: Distributed collaborative applications for supporting complex use cases in mobile environments have to provide contextual information (e.g. presence and group awareness) via their user interface. Social interaction and data sharing — being essential aspects of distributed collaborative applications — typically result in conflicting goals, primarily awareness vs. privacy. Preserving the end users' privacy especially in mobile collaborative settings is the most often-cited point of critique of mobile and ubiquitous computing. Since usability is a prerequisite for privacy and awareness mechanisms especially for mobile applications, we report in this paper on how to balance usability, privacy, and awareness trade-offs when building mobile collaborative applications. This is complemented by new approaches for preserving privacy tailored to the needs of respective communities in the domain of decentralized group-centric solutions. The requirements were gathered through an analysis of user's needs as well as first evaluations of prototypes. Those were built for different case studies focusing on privacy, trust, and identity management in real-life communities. We report on the outcomes of our work and show this exemplary with the help of a mobile prototype application to support an Angling Community with privacy and collaboration needs related to location-based services.

Description: We reconstructed marine fisheries catches for the Federal Republic of Germany within the North Sea (specifically ICES area IVb) from 1950-2010. ICES landings statistics are used as a reported baseline, and then adjusted using information from ICES stock assessment working group reports, national data, and expert knowledge to estimate unreported landings, recreational and subsistence catches and major discards. Brown shrimp (Crangon crangon) contribute the most to unreported landings and discards. Atlantic herring (Clupea harengus), Atlantic cod (Gadus morhua) and European plaice (Pleuronectes platessa) are also important fisheries for the period 1950-2010. The reconstructed total catch of 8.5 million t from 1950-2010 was approximately 63% higher than the baseline reported ICES landings of 5.2 million t. The reconstructed total catch of invertebrates is almost 4 million t, which is 2 times the ICES baseline catch which is just over 1.9 million t. The reconstructed catch for all finfish species is 4.6 million t and is 41% higher than the ICES baseline catch of 3.3 million t. These discrepancies are largely driven by discarded catches that are not accounted for in officially reported (ICES) data, which also form the globally reported data as presented by the Food and Agriculture Organization of the United Nations. Our results demonstrate the importance of comprehensively accounting for and disclosing fisheries data to the public (including discarded catches), and effectively monitoring Illegal, Unreported and Unregulated (IUU) catches.