Living continental shelf foraminifera were studied at three stations along a shore to open ocean transect between 39 and 69 m depth in the West-Gironde Mud Patch (WGMP) (Bay of Biscay, NE Atlantic). The aim of this work was to understand how the complex temporal variability of the environmental conditions (e.g., hydro-sedimentary processes, sedimentary organic matter, oxygenation levels) controls foraminiferal ecological pat-terns (i.e., diversity, faunal composition, standing stock, and microhabitats). The WGMP was sampled during three different seasons (boreal summer - August 2017; winter - February 2018 and spring - April 2018), with very different meteorological patterns and benthic environmental conditions. The sedimentary facies at the shallowest station (Station 1, 39 m) varies significantly due to hydrometeorological constraints (strong storms and swells), which are extremely marked in late autumn and during the winter. The erosion of the sandy substrate by strong bottom currents and the deposition of a silty surface layer leads to the recorded spectacular drop in foraminiferal diversity and density recorded in February and April 2018. All foraminiferal species were affected by this hydrosedimentary instability, likely due to the partial destruction of their microhabitat by intense erosional and depositional processes. At the middle WGMP station (Station 2, 47 m), benthic fauna changed much more gradually. The sedimentary imprint of the spring phytoplankton bloom is clearly recorded in April 2018 with an increase in fresh and altered phytopigment content in surface sediments. Eggerelloides scaber, a deposit feeder and hypoxia-tolerant species, dominated the 2017 summer foraminiferal fauna but was gradually replaced by Ammonia falsobeccarii, a phytophagous taxon considered quite reactive to spring bloom inputs. At the distal WGMP (Station 4, 69 m), E. scaber and A. falsobeccarii were outcompeted and gradually replaced by Nonion faba and Nonionoides turgidus, both highly adaptable species able to settle down in surface and subsurface sediments during the spring bloom periods. Able to endure a range of microhabitats and food availability, there they rely on both fresh and altered phytodetritus. We propose a conceptual scheme summarizing the putative interconnexion between foraminiferal faunas, geochemistry and physics in the WGMP.

Live (Rose Bengal stained) shelf foraminiferal faunas have been studied at seven stations located along a shore open ocean transect between 39 and 69-m depth in the West-Gironde Mud Patch (WGMP) (Bay of Biscay, NE Atlantic) to understand how complex environmental conditions (e.g., organic matter, oxygenation, sedimentary facies) control their ecological patterns (i.e., diversity, faunal composition, standing stock, and microhabitats). To do so, the WGMP was sampled in August 2017, at the end of the succession of phytoplankton blooms occurring in spring and summer. This morpho-sedimentary unit is bathed by well-oxygenated bottom waters and characterized by clay-silt facies containing variably degraded phytodetritus and traces of terrestrial organic matter. Oxygen penetration depth within the sediment is less than 7 +/- 3 mm, indicating efficient organic matter in-sediment mineralization by aerobic respiration. Foraminiferal richness (S) presents relatively moderate values ranging between 15 and 35 taxa. According to Shannon Index H', foraminiferal diversity tends to increase with water depth. Accordingly, the relative contribution of Eggerelloides scaber, the dominant foraminiferal species at all stations, decreases with increased depth and decreased proximity to the coast. The shallowest station (Station 1, 39 m), closest to the shore, is characterised by E. scaber, Quinqueloculina laevigata and Ammonia beccarii, species typical of inner-shelf environments constrained by high-energy hydrodynamics and river discharge. Surficial sediments at Station 1 constitute of winnowed sands depleted in organic carbon. Towards the centre of the WGMP, where clay-silt facies contain variably degraded marine phytodetritus and terrestrial organic compounds, foraminiferal faunas are characterized by Bulimina aculeata, Ammonia falsobeccarrii, Nouria polymorphinoides and Nonionoides turgidus. Yet E. scaber remains the most dominant taxon. Deeper stations (> 55 m depth) located at the distal part of the mud patch are dominated by B. aculeata, A. falsobeccarrii, N. polymorphinoides and E. scaber. Accompanying these taxa are Bulimina marginata, Rectuvigerina phlegeri, Nonion faba and Paracassidulina neocarinata, which are typical of mid-and outer-shelf ecosystems enriched in sedimentary organic matter.

Our aim in the EU funded JERICO project was to develop a flexible and scalable imaging platform that could be used in the widest possible set of ecological situations. Depending on research objectives, both image acquisition and analysis procedures may indeed differ. Up to now the attempts for automating image analysis procedures have consisted of the development of pieces of software specifically designed for a given objective. This led to the conception of a new software: AVIExplore. Its general architecture and its three constitutive modules: AVIExplore — Mobile, AVIExplore — Fixed and AVIExplore — ScriptEdit are presented. AVIExplore provides a unique environment for video analysis. Its main features include: (1) image selection tools allowing for the division of videos in homogeneous sections, (2) automatic extraction of targeted information, (3) solutions for long-term time-series as well as large spatial scale image acquisition, (4) real time acquisition and in some cases real time analysis, and (5) a large range of customized image-analysis possibilities through a script editor. The flexibility of use of AVIExplore is illustrated and validated by three case studies: (1) coral identification and mapping, (2) identification and quantification of different types of behaviors in a mud shrimp, and (3) quantification of filtering activity in a passive suspension-feeder. The accuracy of the software is measured comparing with visual assessment. It is: 90.2%, 82.7%, and 98.3% for the three case studies, respectively. Some of the advantages and current limitations of the software as well as some of its foreseen advancements are then briefly discussed.

Live (Rose-Bengal stained) deep-sea foraminiferal faunas have been studied at four stations between 530 and 3200-m depth in the Mozambique Channel (eastern Africa) to understand how complex environmental conditions (e.g., organic matter, oxygenation) control their ecological structure (i.e., diversity, density, and microhabitats). Two upper-slope stations, located at 530- and 780-m depth off Madagascar, are bathed by well-oxygenated bottom waters. They are characterized by fine sediments enriched in highly degraded organic matter (low amino-acid bio-availability and reduced chlorophyllic freshness). Mineralization of organic compounds results in relatively moderate oxygen penetration depth (i.e., 15 and 30mm) in sediment. Interestingly, foraminiferal species richness (S) is exceptionally high at both sites. The highest densities are observed in the 780-m deep station, where peculiar sedimentary facies of organic matter are recorded (OC >2.0% DW). Redox conditions and sedimentary organic matter control the composition and the vertical distribution (i.e. microhabitat) of benthic faunas at both upper-slope sites. Bolivina alata, Bulimina marginata, Haplophragmoides bradyi and Nouria compressa are relevant bio-indicators of enhanced burial of organic matter prevailing at the 780-m deep station (i.e., eutrophic conditions), whereas Uvigerina hispida and Uvigerina semiornata are dominant at the 530-m deep station (i.e., relatively mesotrophic conditions). Two other stations are located on well-ventilated terraces from the deep-sea canyons of Tsiribihina and Zambezi (>3000-m depth). They are characterized by carbonate ooze, which is depleted in degraded organic matter and, where oxygen penetration depth is relatively deep (i.e.,>80mm). Because of food scarcity, S and densities are relatively low, and agglutinated and organic-walled taxa dominate foraminiferal faunas. Hospitella fulva, a foraminiferal species belonging to Allogromiida, occupies very deep infaunal microhabitat, what disrupts the classical scheme of microhabitat patterns in oligotrophic settings.

We present ecological and isotopic (δ18O and δ13C) data on benthic foraminifera sampled from 4 deep-sea stations in a pockmark field from the deep-water Niger delta (Gulf of Guinea, Equatorial Atlantic Ocean). In addition, a series of sedimentological and (bio)geochemical data are shown to back up foraminiferal observations. All stations are located within 1.2 km of each other, so prevailing oceanographic conditions can be assumed to be similar at each site. Two of the sites (GMMC-01 and GMMC-02) are located in a pockmark (named "pockmark A") where current methane seepages were recorded by ROV observations. A third station (GMMC-03) is located in the topographic depression interpreted as a collapsed pockmark (named "pockmark B"). The fourth site (GMMC-04) is a reference station, without evidence of past or present seepages. Our observations show that degraded organic matter with low bio-availability is present at all stations with a preferential burial of organic compounds in topographic depressions (GMMC-03 station). Authigenic aragonite is abundant in surface sediments at stations GMMC-01 and -02. Its precipitation is likely related to high rates of methane oxidation during past seep events in episodically active pockmark A. In contrast, the absence of anaerobic methanotrophic Archaea (ANME) during the sampling period (November 2011) suggests that only moderate sulphide and methane oxidation take place close to the sediment–water interface. Compared to the reference site GMMC-04, living foraminifera at the collapsed and episodically active pockmarks show minor changes in terms of diversity, standing stocks and faunal composition. However, the δ13C signal of living and dead (but well-preserved) foraminiferal species (Ceratobulimina contraria, Melonis barleeanus, Uvigerina peregrina) is depleted in the episodically active pockmark A compared to the other stations. Overgrowth of authigenic carbonate on altered foraminifera generates an important shift to lower δ13C values. Dead faunas carry a complex time-averaged message, integrating taphonomic gains and losses related to the temporal variability of gas emission. They reveal major faunal differences that may be useful to detect gas hydrate seepages in different pockmark stages.

Ongoing global warming is affecting the polar regions at a faster pace than in many other lower latitude environments. Based on the idea that the changes at the sea surface leave a signal in the sedimentary record, we analysed the total hydrolysable amino acid (THAA) and enzymatically hydrolysable amino acid (EHAA) contents in sediments off the coast of the eastern Antarctic Peninsula during the decade following the collapse of sections A and B of the Larsen ice shelf to check their utility as biomarkers of this event. Two organic matter lability indexes (the EHAA-to-THAA ratio and the Dauwe degradation index) were also calculated to assess the quality of the organic matter in the sediment column. The THAA and EHAA concentrations in the upper 5 mm varied between ~1 and ~10 nmol mg−1 DW−1, corresponding to an oligotrophic environment, whereas the quality of the organic matter as indicated by the lability indexes was relatively high in the upper sediment column (<2 cm deep). The amino acid profiles and indexes in the sediment column were compared to the pigment profiles and indexes published in previous studies for the same stations. The results suggest that in the sediment column, pigments track more accurately than amino acids the pelagic organic matter supply to the seabed after the collapse of the Larsen ice shelf.

Sediment Profile Images (SPIs) are widely used for benthic ecological quality assessment under various environmental stressors. The processing of the information contained in SPIs is slow and its interpretation is largely operator dependent. We report here on a new software: SpiArcBase, which allows for a semi-automatic analysis of SPIs and facilitates the interpretation of observed features. SpiArcBase enhances the objectivity of the information extracted from SPIs, especially for the assessment of the apparent Redox Potential Discontinuity (aRPD). This new software also allows the user to create and manage a database containing original SPIs and corresponding derived pieces of information. Examples of the use of SpiArcBase for SPIs collected during a case study carried out within the Rhône River Prodelta are provided. Correlations between: (1) visually and automatically assessed aRPD and Benthic Habitat Quality Index (BHQ), and (2) automatically assessed aRPD and BHQ and surface sediment organic carbon support the use of this new software.

The origin and composition of sediment organic matter (SOM) were investigated together with its spatial distribution in the Arcachon Bay – a macrotidal lagoon that shelters the largest Zostera noltii meadow in Europe – using elemental and isotopic ratios. Subtidal and intertidal sediments and primary producers were both sampled in April 2009. Their elemental and isotopic compositions were assessed. Relative contributions of each source to SOM were estimated using a mixing model. The SOM composition tended to be homogeneous over the whole ecosystem and reflected the high diversity of primary producers in this system. On average, SOM was composed of 25% of decayed phanerogams, 19% of microphytobenthos, 20% of phytoplankton, 19% of river SPOM and 17% of macroalgae. There was no evidence of anthropogenic N-sources and SOM was mainly of autochthonous origin. None of the tested environmental parameters – salinity, current speed, emersion, granulometry and chlorophyll a – nor a combination of them explained the low spatial variability of SOM composition and characteristics. Resuspension, mixing and redistribution of the different particulate organic matters by wind-induced and tidal currents in combination with shallow depth probably explain the observed homogeneity at the whole bay scale.

Numerical structure and the organisation of food webs within macrozoobenthic communities has been assessed in the European waters (Svalbard, Barents Sea, Baltic Sea, North Sea, Atlantic Ocean and the Mediterranean Sea) to address the interactions between biodiversity and ecosystem functioning. Abundance and classical species diversity indices (S, H', J) of macrofaunal communities were related to principal attributes of food webs (relative trophic level and food chain length, FCL) that were determined from carbon and nitrogen stable isotope values. Structure of marine macrobenthos varies substantially at a geographical scale; total abundance ranges from 63 ind. m(-2) to 34,517 ind. m(-2), species richness varies from 3 to 166 and the Shannon-Weaver diversity index from 0.26 to 3.26 while Pielou's evenness index is below 0.73. The major source of energy for macrobenthic communities is suspended particulate organic matter, consisting of phytoplankton and detrital particles, sediment particulate organic matter, and microphytobenthos in varying proportions. These food sources support the presence of suspension- and deposit-feeding communities, which dominate numerically on the sea floor. Benthic food webs include usually four to five trophic levels (FCL varies from 3.08 to 4.86). Most species are assigned to the second trophic level (primary consumers), fewer species are grouped in the third trophic level (secondary consumers), and benthic top predators are the least numerous. Most species cluster primarily at the lowest trophic level that is consistent with the typical organization of pyramidal food webs. Food chain length increases with biodiversity, highlighting a positive effect of more complex community structure on food web organisation. In more diverse benthic communities, energy is transferred through more trophic levels while species-poor communities sustain a shorter food chain. (C) 2011 Elsevier Ltd. All rights reserved.

In March 2002, 3200km2 of the Larsen B ice shelf collapsed off the Eastern Antarctic Peninsula (EAP). In the austral summer of 2006, sea floor sediment was recovered beneath the extinct Larsen B ice shelf and in a region off the Northern Antarctic Peninsula (NAP), which has been free of ice shelves for more than 1000yr. To assess changes in the chemical composition of the sediment after ice shelf collapses, chlorophylls and pheophytins were measured in sediment cores at six stations. This is the first time that chlorophyll pigments have been analysed in sediment samples from regions under recently collapsed ice shelves. Five years after the ice shelf collapse, Chla and Chlc concentrations were similar in the interfacial sediment (upper 1cm) of NAP and EAP regions. However, in EAP Chla and Chlc concentrations decreased more rapidly with depth in the sediment column and were negligible below 2cm depth. The high Chla to Pheoa ratios indicated that sedimentary pigments found in EAP had undergone limited degradation suggesting that they were locally produced rather than laterally advected. Complementary information from excess 210Pb activity and diatom valve distributions provided further evidence that the pigment fluxes to the seabed in EAP took place only after the ice shelf collapse.

River deltas are particularly important in the marine carbon cycle as they represent the transition between terrestrial and marine carbon: linked to major burial zones, they are reprocessing zones where large carbon fluxes can be mineralized. In order to estimate this mineralization, sediment oxygen uptake rates were measured in continental shelf sediments and river prodelta over different seasons near the outlet of the Rhône River in the Mediterranean Sea. On a selected set of 10 stations in the river prodelta and nearby continental shelf, in situ diffusive oxygen uptake (DOU) and laboratory total oxygen uptake (TOU) measurements were performed in early spring and summer 2007 and late spring and winter 2008. In and ex situ DOU did not show any significant differences except for shallowest organic rich stations. Sediment DOU rates show highest values concentrated close to the river mouth (approx. 20 mmol O2 m−2 d−1) and decrease offshore to values around 4.5 mmol O2 m−2 d−1 with lowest gradients in a south west direction linked to the preferential transport of the finest riverine material. Core incubation TOU showed the same spatial pattern with an averaged TOU/DOU ratio of 1.2±0.4. Temporal variations of sediment DOU over different sampling periods, spring summer and late fall, were limited and benthic mineralization rates presented a stable spatial pattern. A flood of the Rhône River occurred in June 2008 and delivered up to 30 cm of new soft muddy deposit. Immediately after this flood, sediment DOU rates close to the river mouth dropped from around 15–20 mmol O2 m−2 d−1 to values close to 10 mmol O2 m−2 d−1, in response to the deposition near the river outlet of low reactivity organic matter associated to fine material. Six months later, the oxygen distribution had relaxed back to its initial stage: the initial spatial distribution was found again underlining the active microbial degradation rates involved and the role of further deposits. These results highlight the immediate response of the sediment oxygen system to flood deposit and the rapid relaxation of this system towards its initial state (6 months or less) potentially linked to further deposits of reactive material.

Deposit-feeders are the dominant bioturbators of aquatic sediments, where they profoundly impact biogeochemical processes, but they are also vulnerable to both lethal and non-lethal predation by a large variety of predators. In this study, we performed a series of experiments to test the effects of predation avoidance on the feeding activity and sediment reworking intensity of the deposit-feeding bivalve Macoma balthica. Feeding activity at the sediment–water interface and sediment reworking intensity (vertical displacements of inert particle tracers) were monitored using image analysis techniques for treatments including and excluding the predatory shrimp, Crangon crangon. Detection of C. crangon by M. balthica resulted in an immediate retraction of the feeding siphon and a reduction in feeding activity. M. balthica also buried deeper into the sediment in the presence of C. crangon. This predator avoidance behaviour indirectly affected sediment reworking modes and rates, increasing the thickness of the bioturbated sediment layer as well as the non-local transport of sediment particles at depth. Conversely, feeding activity and sediment reworking processes remained unaffected when C. crangon was present, but isolated from the sediment, suggesting that predator perception in M. balthica is tactile (i.e. induced by direct encounter) rather than being chemosensory. Collectively, these results demonstrate that predatory avoidance behaviour by benthic infauna can significantly impact benthic bioturbation and the incorporation of organic matter into the benthic food web.

Latitudinal clines in species diversity in limnic and terrestrial habitats have been noted for well over a century and are consistent across many taxonomic groups. However, studies in marine systems over the past 2 to 3 decades have yielded equivocal results. We conducted initial analyses of the MarBEF (EU Network of Excellence for Marine Biodiversity and Ecosystem Function) database to test for trends in local and regional diversity over the latitudinal extent of European continental-shelf waters (36° to 81° N). Soft-sediment benthic macrofauna exhibit little evidence of a latitudinal cline in local (α-) diversity measures. Relationships with water depth were relatively strong and complex. Statistically significant latitudinal trends were small and positive, suggesting a modest increase in diversity with latitude once water-depth covariates were removed. These results are consistent regardless of whether subsets of the database were used, replicates were pooled, or component tax- onomical groups were evaluated separately. Local and regional diversity measures were significantly and positively correlated. Scientific cooperation through data-sharing is a powerful tool with which to address fundamental ecological and evolutionary questions relating to large-scale patterns and processes.

Macroecology provides a novel conceptual framework for analysis of the distribution and abundance of organisms at very large scales. Its rapid development in recent years has been driven primarily by Studies of terrestrial taxa; the vast potential of marine systems to contribute to the macroecological research effort remains largely Untapped. International collaborative, efforts Such as MarBEF have provided fresh impetus to the collation of regional databases of species Occurrences, Such as the newly available MacroBen database of the European soft sediment benthic fauna. Here, we provide a first macroecological summary of this unique database. We show that in common with almost. all previously analysed assemblages, the frequency distribution of regional Site Occupancies across species in the MacroBen database is strongly right-skewed. More unusually, this right skew remains under logarithmic transformation. There is little evidence for any major differences between higher taxa in this frequency distribution (based on the 8 animal classes for which we have Sufficient data). Indeed, considerable variation in occupancy persisted across the taxonomic hierarchy, such that most variation occurred between species within genera. There was a weak positive relationship between local population density and regional Occupancy across species, but this abundance-occupancy relationship varied considerably between higher taxa and between geographical areas. Our results highlight the potential of databases such as MacroBen to consolidate macroecological generalities and to test emerging theory.

We analyzed patterns of species diversity in a compiled data set covering the European coast (from Norway to Crete) that was made available in the framework of the MarBEF European Network of Excellence. The focus was on the distribution patterns of species diversity over large areas across Europe. The objectives of our analysis were two-fold. First, we attempted to separate the effects of species-area relationships from that of species accumulation. Second, we explored the relationship between species diversity and productivity, and compared this to the proposed explaining factors (depth, survey area and latitude). The following conclusions are drawn. (1) Within a given habitat (subtidal soft sediment), the distribution of marine macrofaunal species richness in different areas between 3 and 200 m in average depth throughout Europe is shown to follow general rules derived from observations and experiments mostly based on terrestrial communities; (2) soft-bottom macrofauna accumulate in the subtidal environment (tip to 200 in) following the Arrhenius plot model at a rate (approximate to 0.5) corresponding to about a 3-fold increase in the number of species when the sampling area increases by 1 order of magnitude; (3) the distribution of the intrinsic species richness (point species richness) between the selected data sets (subtidal soft sediment) is significantly correlated with the levels of organic flux reaching the sea bottom; and (4) the close relationship between depth and the fraction of surface primary production that reaches the sea bottom is proposed as an explanation for the previously described increase of species richness with depth.

This study examines whether or not biogeographical and/or managerial divisions across the European seas can be validated using soft-bottom macrobenthic community data. The faunal groups used were: all macrobenthos groups, polychaetes, molluscs, crustaceans, echinoderms, sipunculans and the last 5 groups combined. In order to test the discriminating power of these groups, 3 criteria were used: (1) proximity, which refers to the expected closer faunal resemblance of adjacent. areas relative to more distant ones; (2) randomness, which in the present context is a measure of the degree to which the inventories of the various sectors, provinces or regions may in each case be considered as a random sample of the inventory of the next largest province or region in a hierarchy of geographic scales; and (3) differentiation, which provides a measure of the uniqueness of the pattern. Results show that only polychaetes fulfill all 3 criteria and that the only marine biogeographic system supported by the analyses is the one proposed by Longhurst (1998). Energy fluxes and other interactions, between the planktonic and benthic domains, acting over evolutionary time scales, can be associated with the multivariate pattern derived from the macrobenthos datasets. Third-stage multidimensional scaling ordination reveals that polychaetes produce a unique pattern when all systems are under consideration. Average island distance from the nearest coast, number of islands and the island surface area were the geographic variables best correlated with the community patterns produced by polychaetes. Biogeographic patterns suggest a vicariance model dominating over the founder-dispersal model except for the semi-closed regional seas, where a model substantially modified from the second option could be supported.

The pan-European MacroBen database was used to compare the AZTI Marine Biotic Index (AMBI) and the Benthic Quality Index (BQI ES ), 2 biotic indices which rely on 2 distinct assessments of species sensitivity/tolerance (i.e.AMBI EG and BQI E[S 50 ] 0.05 ) and which up to now have only been compared on restricted data sets.A total of 12 409 stations were selected from the database.This subset (indicator database) was later divided into 4 marine and 1 estuarine subareas.We computed E(S 50 ) 0.05 in 643 taxa, which accounted for 91.8% of the total abundances in the whole marine indicator database.AMBI EG and E(S 50 ) 0.05 correlated poorly.Marked heterogeneities in E(S 50 ) 0.05 between the marine and estuarine North Sea and between the 4 marine subareas suggest that sensitivity/tolerance levels vary among geographical areas.High values of AMBI were always associated with low values of BQI ES , which underlines the coherence of these 2 indices in identifying stations with a bad ecological status (ES).Conversely, low values of AMBI were sometimes associated with low values of BQI ES resulting in the attribution of a good ES by AMBI and a bad ES by BQI ES .This was caused by the dominance of species classified as sensitive by AMBI and tolerant by BQI ES .Some of these species are known to be sensitive to natural disturbance, which highlights the tendency of BQI ES to automatically classify dominant species as tolerant.Both indices thus present weaknesses in their way of assessing sensitivity/tolerance levels (i.e.existence of a single sensitivity/tolerance list for AMBI and the tight relationship between dominance and tolerance for BQI ES ).Future studies should focus on the (1) clarification of the sensitivity/tolerance levels of the species identified as problematic, and (2) assessment of the relationships between AMBI EG and E(S 50 ) 0.05 within and between combinations of geographical areas and habitats.

Local species diversity may be determined by processes operating locally, such as disturbance, predation and competition, or by regional processes, such as environmental structuring or history. Classical theory focusing on competition predicts that the species combining to form communities will be less similar to each other than they would be if they were assembled at. random from a regional species pool, Theory focusing on environmental structuring predicts that species will be more similar to each other than expected by chance. A randomisation test that determines the extent to which local species lists represent random selections from a regional list, based on the average relatedness between species, was applied to data held in the MacroBen database. Little or no evidence was found for species lists of whole faunas at any scale being random subsets of species lists at larger scales. Species tend to be more closely related to each other than would be expected if they were assembled at random. Thus marine soft-sediment macrofauna are not locally assembled at random from regional species pools and it is likely that regional processes determine the assembly of communities. Focusing on the most abundant class within the macrofauna, a different pattern emerges, in that there is a much stronger tendency for local polychaete composition to be a random subset from regional pools at all scales. Thus it is not possible to determine whether local polychaete diversity is independent of both local and regional processes, or determined by a combination of both acting antagonistically.

We describe an integrated database on European macrobenthic fauna, developed within the framework of the European Network of Excellence MarBEF, and the data and data integration exercise that provided its content. A total of 44 datasets including 465354 distribution records from soft-bottom macrobenthic species were uploaded into the relational MacroBen database, corresponding to 22897 sampled stations from all European seas, and 7203 valid taxa. All taxonomic names were linked to the European Register of Marine Species, which was used as the taxonomic reference to standardise spelling and harmonise synonymy. An interface was created, allowing the user to explore, subselect, export and analyse the data by calculating different indices. Although the sampling techniques and intended use of the datasets varied tremendously, the integrated database proved to be robust, and an important tool for studying and understanding large-scale long-term distributions and abundances of marine benthic life. Crucial in the process was the willingness and the positive data-sharing attitude of the different data contributors. Development of a data policy that is highly aware of sensitivities and ownership issues of data providers was essential in the creation of this goodwill.