Examining Source-Receptor Relationships for Mercury in Scandinavia Modelled and Empirical Evidence

The atmosphere remains the major source of mercuryin Swedish ecosystems. Since the late eighties,atmospheric emissions of mercury have drasticallydecreased in Europe. Wet deposition of mercury hasdecreased over the last decade but still exhibitsa clear south-to-north gradient, greatlyinfluenced by source areas in northern and centralEurope. The decreases in emissions can beattributed to both direct measures to close knownpoint sources and a declining economy and energyconsumption in many East European countries.Further reductions of mercury emissions willrequire that other source categories such asindirect emissions from mercury-containingproducts and crematories are be considered.     

Molecular phylogeography of two Italian sibling species of Calobius (Coleoptera, Hydraenidae, Ochthebiinae) inhabiting Mediterranean marine rock-pools

Marine rock-pools, commonly found along the Mediterranean coasts, are isolated patches of habitat characterised by large spatial and temporal variations. The phylogeography of Calobius quadricollis and C. urbanelliae, two sibling species of moss beetles (Coleoptera, Hydraenidae) inhabiting Italian temporary marine rock-pool ecosystems, were studied using mitochondrial cytochrome c oxidase subunit I (COI). Our data suggest a strong association between the scored genetic variability and the geographical distribution of populations sampled for both species. These analyses provided evidences of episodic species range expansion and fragmentation, recurrent “flush and crash” and bottleneck episodes probably occurring during the Glacial Cycles. The observed phylogeographical pattern is probably related to the historical and biogeographical processes of Mediterranean areas, as well as both to the ephemeral habitat tipology and limited dispersal ability of these beetles.     

Filtration rate in seven Scandinavian ascidians: implications of the morphology of the gill sac

The ascidian branchial basket is functionally responsible for pumping water through the animal. Within Ascidiacea the branchial basket and the stigmata are morphologically variable and these features are important taxonomical characters. However, the functional significance of this morphological variation has not been studied in great detail. Here, we have measured filtration rates in seven ascidians: Clavelina lepadiformis (Order Aplousobranchiata); Ciona intestinalis, Corella parallelogramma, Ascidia virginea (Order Phlebobranchiata); Boltenia echinata, Molgula manhattensis, Pyura tessellata (Order Stolidobranchiata) and compared these rates with the morphological characteristics of the branchial basket and the stigmata. Filtration rates were measured in the laboratory and determined from an exponential reduction in algal cell (Rhodomonas sp.) concentration as a function of time. The branchial baskets of the experimental ascidians were dissected free and photographs were taken of the entire basket and of the stigmata. It was found that filtration rates in the investigated ascidians are determined primarily by the area of the branchial basket and the length of the ciliary band lining the stigmatal openings, and that the form of the stigmatal opening has no impact on filtration rates.     

Prerequisites for learning from accident investigations – A cross-country comparison of national accident investigation boards

In this paper railway accident investigation reports issued by the national accident investigation boards in three Scandinavian countries during a 2-year period have been systematically studied. Content analysis of attributed causes in these reports reveals a considerable emphasis on physical processes, actor activities and equipment (the microlevel). Much less attention is paid to organisational factors (the mesolevel) and conditions related to regulators, associations and government (the macrolevel). This means that lessons will primarily be learned about aspects at the lower of these levels. Interviews show that the factors emphasised in investigation reports typically reflect the competences and experiences of the investigators, i.e. they are inclined to focus on areas of their own expertise. Since failures at the microlevel in many cases merely are symptoms of trouble at higher levels, it is argued that competence among investigators that supplements entirely technical or operational backgrounds are necessary for enabling deeper understanding of the factors leading to accidents. One possible way for achieving this is the creation of multi-modal investigation boards that provide a number of potential advantages, such as increased access to specialist competences that are shared between different sectors. Although a multi-modal approach to some degree has been adopted in all three countries, interviews reveal that these positive effects do not emerge automatically. It can therefore be concluded that multi-modal investigation boards offer a number of possible advantages, but only when these synergies are fully exploited can they provide a potential for more effective learning from accidents.