The MAREANO (Marine AREA database for NOrwegian coast and sea areas) mapping programme includes acquisition of multibeam bathymetry and backscatter data together with a comprehensive, integrated biological and geological sampling programme. Equipment used includes underwater video, box corer, grab, epibenthic sled and beam trawl. Habitat maps are produced by combining information on landscapes, landscape elements, sediment types and biological communities. Video observations provide information about the megafauna diversity of large ([1 cm) epifauna and bottom types, whilst bottom samples describe the composition of epifauna, hyperfauna (crustaceans living in the upper part of the sediment and/or swimming just above the substratum) and infauna, and sediment composition. In this study, two biological data sets are used to study fauna response to environmental heterogeneity at two different spatial scales: (1) broad scale, megahabitat (1-10s km), based on information about megafauna taxa observed during video surveys in the Nordland/ Troms area, (2) fine scale, mesohabitat (10s m-1 km), based on information about species composition documented with video records and bottom sampling gear from the bank ''Tromsøflaket''. In general, the highest diversity is found on bottoms with mixed substrates indicating that substratum heterogeneity is very important for the biodiversity at both scales. The number of taxa shows a maximum at depths between 200 and 700 m followed by a gradual decrease down to 2,200 m. At the broad scale, multibeam data provides a variety of terrain variables that indicate environmental variation (e.g. exposure to currents, interpreted substrates). This analysis identifies six fauna groups associated to specific landscape elements. Diversity of megafauna shows a strong correlation with number of bottom types occurring along video transects. It is highest at the shelf break and decreased with depth on the slope in parallel with a decrease in habitat heterogeneity and temperature. At a fine scale, six biotopes are identified based on megafauna composition with habitat characteristics ranging from homogenous muddy bottom, biotope 1, to the most heterogeneous bottom with [20% rocks and several bottom types present in biotope 6. The macrofauna 123Hydrobiologia ( ) 685:191-219 DOI 10.1007 sampled is used for description of the whole benthic community, including diversity, biomass and production, related to these six biotopes. The variation in percentage cover of substrate types and in particular the cover of hard substrates demonstrate to be a good proxy for the benthic community composition (megaand macrofauna) and its diversity.

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Information about the distribution, composition and status of the benthic environment and communities is important for the implementation of ecosystem-based management involving assessment of the effects of human activities. The MAREANO programme (Marine Areal Database for Norwegian Coasts and Sea Areas) conducts seabed mapping in order to fill knowledge gaps in relation to the implementation of management plans for the Norwegian EEZ. This paper describes the experience from the mapping strategy used by MAREANO. By using a variety of sampling gears the benthic environment and communities from all types of seabed are thoroughly documented. This involves the mapping of bottom topography, seabed substratum, pollutants, species composition, biomass and habitat forming vulnerable biota in a varied marine landscape. The area mapped from 2006 to 2013 is 131,000 km 2 , spans depths ranging from 40 to 2700 m and covers a variety of topographic features including canyons, cold seeps and coral reefs. The information gained by this broad mapping approach has offered a unique insight into the diversity of benthic species and habitats. Through interpretation and classification of the information gained MAREANO scientists produce a database and detailed maps of seabed surficial geology, marine landscapes, biotopes and particularly sensitive and threatened habitats. Indicators of human impact, such as pollutants, trawl marks and marine litter are also presented on maps. Experience from 8 years of detailed mapping shows the necessity of thorough mapping for informed management decision-making.

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Based on personal observations and questionnaires to Norwegian fish farmers, the behavior of three species and several different stocks of salmonid fish reared in ocean pens is described. Swimming activity and the constancy of swimming orientation (clockwise or counter clockwise) vary among species. With few exceptions, the orientation of Atlantic salmon (Salmo salar) at any one farm does not change with tide, season, or age offish. Stock origin and/or the early rearing history may impose this directionality. The swimming of Atlantic salmon in pens resembles schooling behavior. Possible departures from this stereotyped behavior are considered. The behavior of pen-reared salmonids and its implications in selective breeding, migratory mechanisms, and fish health are discussed. Key words: salmon, behavior, pen rearing, mariculture, swimming, orientation, Salmo salar, S. gairdneri, Oncorhynchus gorbuscha