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The presence of behavioural rhythms has been studied in organisms of coastal areas in relation to circadian and tidal cycles, but their presence in benthic fauna inhabiting dark deep-sea regions remains largely unknown. Cabled video-observatories allow the study of these activity rhythms via the acquisition of pictures or footages over extended periods of time. In this work, we present the preliminary steps in the automation of biological data extraction for the determination of deep-sea fauna activity rhythms with TEMPO-mini (NEPTUNE; Canada). Automated analyses of tube worm behaviour were carried out with the Hough transform algorithm. Some different testing parameters were applied to the same image with siboglinid tubes. Tube openings identifications showed to be difficult, since circle placing was in some cases attributed to animals. The future step of automation will be to run the Hough transform algorithm within sub Region of Interests were tube identifications is the most efficient as we identified with this preliminary screening. Then, we will focus on each singe individual producing time series in terms of opening identification (as marker of moments of animals’ retractions) per unit of time (e.g. 10 min).

The first Mid-Atlantic hydrothermal vents were discovered in 1985 (Rona et al., 1986), almost 10 years after the first hydrothermal vent discovery at the Galápagos Rift (Lonsdale, 1979). Over three decades of research on these extreme deep-sea ecosystems has improved our knowledge on the mega-and macrofauna inhabiting these peculiar habitats substantially. Less is known about the community structure and the spatial and temporal distributions of the fauna in relation to abiotic andbiotic factors. Ecological time-series studies of temporal variation are indispensable to comprehend the functioning of an ecosystem. However, such studies at hydrothermal vents are scarce and mostly restricted to well-known and more accessible sites in the East Pacific Ocean (EPR and NEP). Imagery analysis is an important tool to assess temporal variation at these often remote and extreme ecosystems both under conitions of continuous venting (Hessler et al., 1985, 1988; Fustec et al., 1987; Sarrazin et al., 1997; Desbruyères, 1998) and post-eruptive nascent vent development (Tunnicliffe et al., 1997; Shank et al., 1998a; Tsurumi & Tunnicliffe, 2001; Shank et al., 2003; Nees et al., 2008; Marcus et al., 2009). Until now, only one single long-term temporal dynamics study is available for the Mid-Atlantic Ridge (MAR), where decadal-scale changes were assessed at the TAG sulfide mound (Copley et al., 2007a). The study presented here is the first high-resolution long-term variations study on the Mid-Atlantic Ridge, investigating both long-term (>10 years) variations in community structure as well as dynamics on shorter time-scales (1 to 4 years). In this dissertation, assemblage distribution patterns and zonation on the Eiffel Tower edifice (part of the Lucky Strike vent field, south of the Azores, situated at a mean depth of 1700m) is assessed by use of image analyses. The protocol wielded is described, which then was elaborated to allow comparisons between the years and to study 14 years of community dynamics. Trends in temporal variations are described. Overall decadal-scale constancy appears to persevere, however on smaller time and spatial scales, changes do occur. A succession model is proposed and a quantification of the rate of change at the slower-spreading MAR is evaluated and compared to that of faster-spreading ridges (NEP). While imagery analysis was used to unravel main temporal and spatial variation trends, discrete biological samples and physico-chemical measurements were analysed to better comprehend the discrepancies observed. Microhabitats were characterised by the extent of fluctuations in environmental variables, while temperature was identified as being a more limiting factor, separating the mussel-based assemblages from the shrimps. In addition, species lists from past and on-going sampling during the French cruises, stored in the Biocean database (Fabri et al., 2006), were analysed to identify changes over time within the Lucky Strike vent field. Based on the data at hand, no significant differences in species composition between different edifices and years were revealed. This dissertation allowed us to gather new insights on the ecosystem functioning of Mid-Atlantic hydrothermal vents. Larger-scale applications and extrapolation of these results and models are proposed, for which the collection of new data is needed.

DIMAS is a 2-year project executed by three Belgian partners (EURAS, VLIZ and Ghent University) and funded by the SPSD II research program of the Belgian Science Policy (BELSPO). Several shipping accidents in Belgian territorial waters, made the various government agencies involved aware of the need to develop tools to assess the risks and impact on marine resources in the case of an accidental release of hazardous substances. DIMAS aims at the protection of the North Sea and Western Scheldt in case of accidental spills from ships. In the present project, a relational database is developed, providing reliable, easy to interpret and up-to-date information on marine specific issues. The database contains the latest information on effects (acute and chronic), absorption, distribution, bioaccumulation/biomagnification, GESAMP hazard profiles and physico-chemical properties for a selection of priority substances and is publicly available (www.vliz.be/projects/dimas). The selection of the substances is based on criteria such as occurrence on priority lists, volumes transported over sea, frequency of involvement in accidental spills and frequency of transports over sea. The first beneficiaries of this database are the people directly involved in the first phase of a containment plan for an accidental spill. The final indirect beneficiaries are the general public (scientists, journalists, general public, etc.) who will be better informed about the potential impact to man and the environment.

Policy makers and marine managers request reliable and meaningful biological baseline maps to be able to make well-deliberated choices concerning sustainable use and conservation in the marine environment. When such maps are lacking one is often obliged to base value assessments on the best available expert judgment. Biological valuation maps compile and summarize all available biological and ecological information for a marine area and allocate an integrated biological value to subzones. Derous et al. (in press) developed a valuation concept around a selected set of valuation criteria (rarity, fitness consequences, aggregation, naturalness and proportional importance). The concept allows the assessment of the intrinsic value of the subzones within an area, on a relative basis. In order to develop a marine biological valuation map for the Belgian part of the North Sea (BPNS), a protocol for the practical application of this valuation concept was developed. After dividing the area into subzones and collecting the available biological data, the protocol allows the scoring of the valuation criteria by answering specific assessment questions. These questions are relevant for the different criteria and incorporate all organizational levels of biodiversity (from the genetic to the ecosystem level). Applying this protocol to the data of the BPNS allowed producing a full-coverage biological valuation map for the area, which integrates knowledge on seabirds, macrobenthos, demersal fish and epibenthos. Separate valuation maps for each ecosystem component are also available, next to reliability maps for each valuation map. These maps can be used as baseline maps for future spatial planning in the BPNS.

Over 500 marine scientists are working together within the framework of MarBEF - a European network of excellence, which started in March 2004. Of all the seas, the European seas are among the most studied in the world. By bringing this expertise and knowledge together, MarBEF aims at a better understanding of long-term and large-scale distribution patterns and functionalities of biodiversity across marine ecosystems. To inventory this wealth of marine life, the European Register of Marine Species (ERMS), at this moment containing nearly 30,000 species names, is adopted and will serve as the reference list and taxonomic backbone within MarBEF. ERMS has been put into a relational database and will be maintained and regularly updated online by a consortium of taxonomic experts. The taxonomic register will be supplemented with biogeographic, ecological and socio-economic information, together with species illustrations, original descriptions and vernacular names. When available, links will be provided with other online species information systems. EurOBIS, the European node of the Ocean biogeographic Information System, is a distributed system that integrates individual datasets on biogeographic information into one large consolidated database and provides the end-user with a fully searchable geographic interface. EurOBIS already captures and freely communicates over 350,000 distribution data from 14,000 species, online. When combining these data with biological, physical, chemical and geologic data, our understanding of the ecosystem will greatly improve, resulting in better ecosystem-based management plans. The Flanders Marine Institute is taking a leading role in these major European data integrating projects within MarBEF and has recently developed online tools for ERMS and EurOBIS (http://www.marbef.org/data).