Search publications of the members of the Royal Belgian institute of natural Sciences
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Seasonal habitat-based density models for a marine top predator, the harbor porpoise, in a dynamic environment
- Effective species conservation and management requires information on species distribution patterns, which is challenging for highly mobile and cryptic species that may be subject to multiple anthropogenic stressors across international boundaries. Understanding species– habitat relationships can improve the assessment of trends and distribution by explicitly allowing high- resolution data on habitats to inform abundance estimation and the identification of protected areas. In this study, we aggregated an unprecedented set of survey data of a marine top predator, the harbor porpoise (Phocoena phocoena), collected in the UK (SCANS II, Dogger Bank), Belgium, the Netherlands, Germany, and Denmark, to develop seasonal habitat- based density models for the central and southern North Sea. Visual survey data were collected over 9 yr (2005–2013) by means of dedicated line- transect surveys, taking into account the proportion of missed sightings. Generalized additive models of porpoise density were fitted to 156,630 km of on- effort survey data with 14,356 sightings of porpoise groups. Selected predictors included static and dynamic variables, such as depth, distance to shore and to sandeel (Ammodytes spp.) grounds, sea surface temperature (SST), proxies for fronts, and day length. Day length and the spatial distribution of daily SST proved to be good proxies for “season,” allowing predictions in both space and time. The density models captured seasonal distribution shifts of porpoises across international boundaries. By combining the large- scale international SCANS II survey with the more frequent, small- scale national surveys, it has been possible to provide seasonal maps that will be used to assist the EU Habitats and Marine Strategy Framework Directives in effectively assessing the conservation status of harbor porpoises. Moreover, our results can facilitate the identification of regions where human activities and disturbances are likely to impact the population and are especially relevant for marine spatial planning, which requires accurate fine- scale maps of species distribution to assess risks of increasing human activities at sea.
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Bacterial and eukaryotic biodiversity patterns in terrestrial and aquatic habitats in the Sør Rondane Mountains, Dronning Maud Land, East Antarctica
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How useful are volunteers for visual biodiversity surveys? An evaluation of skill level and group size during a conservation expedition
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Newly discovered populations of the Ethiopian endemic and endangered Afrixalus clarkei Largen, implications for conservation
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Editorial: The Year of the Monkey and of Global Understanding
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Invasive South American floating plants are a successful substrate for native Central African pleuston
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Aquatic resources in human diet in the Late Mesolithic in Northern France and Luxembourg: insights from carbon, nitrogen and sulphur isotope ratios
- We investigated the contribution of freshwater resources to the diet of seven Late Mesolithic hunter-gatherers (ca. 5300–7000 BC) from Northern France and Luxembourg using stable isotope ratios. In addition to the carbon and nitrogen stable isotope ratios (δ13C, δ15N), we explored the potential of the sulphur isotopic ratios (δ34S) to detect and quantify the proportion of protein derived from aquatic foodstuff. In only two sites, animal remains from an associated settlement were available and subsequently examined to decipher the isotopic differential between terrestrial and freshwater resources. The quantification of their relative contribution was simulated using a Bayesian mixing model. The measurements revealed a significant overlap in δ13C values between freshwater and terrestrial resources and a large range of δ15Nvalues for each food category. The δ34S values of the aquatic and terrestrial animals were clearly distinct at the settlement in the Seine valley, while the results on fish from Belgium demonstrated a possible overlap in δ34S values between freshwater and terrestrial resources. Local freshwater ecosystem likely contributed to ca. 30–40 % of the protein in the diet of the individuals found in the Seine settlement. Out of this context, the isotopic signature and thus contribution of the available aquatic foods was difficult to assess. Another potential source of dietary protein is wild boar. Depending on the local context, collagen δ34S values may contribute to better assessment of the relative contribution of freshwater and terrestrial resources.
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Evidence of a Cooler Continental Climate in East China during the Warm Early Cenozoic
- The early Cenozoic was characterized by a very warm climate especially during the Early Eocene. To understand climatic changes in eastern Asia, we reconstructed the Early Eocene vegetation and climate based on palynological data of a borehole from Wutu coal mine, East China and evaluated the climatic differences between eastern Asia and Central Europe. The Wutu palynological assemblages indicated a warm temperate vegetation succession comprising mixed needle- and broad-leaved forests. Three periods of vegetation succession over time were recognized. The changes of palynomorph relative abundance indicated that period 1 was warm and humid, period 2 was relatively warmer and wetter, and period 3 was cooler and drier again. The climatic parameters estimated by the coexistence approach (CA) suggested that the Early Eocene climate in Wutu was warmer and wetter. Mean annual temperature (MAT) was approximately 16°C and mean annual precipitation (MAP) was 800–1400 mm. Comparison of the Early Eocene climatic parameters of Wutu with those of 39 other fossil floras of different age in East China, reveals that 1) the climate became gradually cooler during the last 65 million years, with MAT dropping by 9.3°C. This cooling trend coincided with the ocean temperature changes but with weaker amplitude; 2) the Early Eocene climate was cooler in East China than in Central Europe; 3) the cooling trend in East China (MAT dropped by 6.9°C) was gentler than in Central Europe (MAT dropped by 13°C) during the last 45 million years.
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Survey on the distribution of the Sweet potato weevil, Cylas species-complex in Ghana (Coleoptera: Brentidae)
- The Sweet potato weevils of the genus Cylas are the most destructive pests of sweet potato and are widely distributed in Africa. The aim of this study was to identify and document the species of Cylas occurring in sweet potato production zones in Ghana. A survey was conducted in 23 localities in 2015 from July to December in seven regions in Ghana in order to determine the identity of the pest. We collected nine thousand and two specimens from Central, Eastern, Greater-Accra, Northern, Volta, Upper-East, and the Upper-West regions. Two species were identified: Cylas brunneus Fabricius, 1797 and Cylas puncticollis Boheman, 1833. Cylas puncticollis occurred in all regions and represented 6,107 specimens (68%), while 2,895 of the specimens (32%) could be assigned to C. brunneus. The latter is restricted to the southern sector including Volta, Central, Eastern and Greater Accra Regions. When considering both species in the southern sector, the Volta Region accounted for 3,117 specimens (48%) followed by 1,447 (22%), 987 (15%), and 980 (15%), from the Central, Eastern, and Greater-Accra Regions, respectively. The dominant species in southern and northern sector was C. puncticollis.
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Early Neanderthal constructions deep in Bruniquel Cave in southwestern France
- Very little is known about Neanderthal cultures, particularly early ones. Other than lithic implements and exceptional bone tools, very few artefacts have been preserved. While those that do remain include red and black pigments3 and burial sites, these indications of modernity are extremely sparse and few have been precisely dated, thus greatly limiting our knowledge of these predecessors of modern humans. Here we report the dating of annular constructions made of broken stalagmites found deep in Bruniquel Cave in southwest France. The regular geometry of the stalagmite circles, the arrangement of broken stalagmites and several traces of fire demonstrate the anthropogenic origin of these constructions. Uranium-series dating of stalagmite regrowths on the structures and on burnt bone, combined with the dating of stalagmite tips in the structures, give a reliable and replicated age of 176.5 thousand years (±2.1 thousand years), making these edifices among the oldest known well-dated constructions made by humans. Their presence at 336 metres from the entrance of the cave indicates that humans from this period had already mastered the underground environment, which can be considered a major step in human modernity.
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Contribution à l'étude des Otiorhynchus Germar, 1822 de la Région de Bruxelles-Capitale et note sur l'espèce invasive O. crataegi Germar, 1824 (Coleoptera: Curculionidae)
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Detecting intruders: assessment of the anthropophilic ant fauna (Hymenoptera: Formicidae) in the city of Abidjan and along access roads in Banco National park (Côte d'Ivoire)
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A systematic review of geological evidence for Holocene earthquakes and tsunamis along the Nankai-Suruga Trough, Japan
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The HNS-MS Project (2015-2016)
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Revision of Bonn Agreement Counter Pollution Manual – Chapter 20 “Inventory of Assessment Tools (Computer Models)”
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Unifying European Biodiversity Informatics (BioUnify)
- In order to preserve the variety of life on Earth, we must understand it better. Biodiversity research is at a pivotal point with research projects generating data at an ever increasing rate. Structuring, aggregating, linking and processing these data in a meaningful way is a major challenge. The systematic application of information management and engineering technologies in the study of biodiversity (biodiversity informatics) help transform data to knowledge. However, concerted action is required to be taken by existing e-infrastructures to develop and adopt common standards, provisions for interoperability and avoid overlapping in functionality. This would result in the unification of the currently fragmented landscape that restricts European biodiversity research from reaching its full potential. The overarching goal of this COST Action is to coordinate existing research and capacity building efforts, through a bottom-up trans-disciplinary approach, by unifying biodiversity informatics communities across Europe in order to support the long-term vision of modelling biodiversity on earth. BioUnify will: 1. specify technical requirements, evaluate and improve models for efficient data and workflow storage, sharing and re-use, within and between different biodiversity communities; 2. mobilise taxonomic, ecological, genomic and biomonitoring data generated and curated by natural history collections, research networks and remote sensing sources in Europe; 3. leverage results of ongoing biodiversity informatics projects by identifying and developing functional synergies on individual, group and project level; 4. raise technical awareness and transfer skills between biodiversity researchers and information technologists; 5. formulate a viable roadmap for achieving the long-term goals for European biodiversity informatics, which ensures alignment with global activities and translates into efficient biodiversity policy.
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Developing priority variables (“ecosystem Essential Ocean Variables” — eEOVs) for observing dynamics and change in Southern Ocean ecosystems
- Abstract Reliable statements about variability and change in marine ecosystems and their underlying causes are needed to report on their status and to guide management. Here we use the Framework on Ocean Observing (FOO) to begin developing ecosystem Essential Ocean Variables (eEOVs) for the Southern Ocean Observing System (SOOS). An eEOV is a defined biological or ecological quantity, which is derived from field observations, and which contributes significantly to assessments of Southern Ocean ecosystems. Here, assessments are concerned with estimating status and trends in ecosystem properties, attribution of trends to causes, and predicting future trajectories. eEOVs should be feasible to collect at appropriate spatial and temporal scales and are useful to the extent that they contribute to direct estimation of trends and/or attribution, and/or development of ecological (statistical or simulation) models to support assessments. In this paper we outline the rationale, including establishing a set of criteria, for selecting eEOVs for the \SOOS\ and develop a list of candidate eEOVs for further evaluation. Other than habitat variables, nine types of eEOVs for Southern Ocean taxa are identified within three classes: state (magnitude, genetic/species, size spectrum), predator–prey (diet, foraging range), and autecology (phenology, reproductive rate, individual growth rate, detritus). Most candidates for the suite of Southern Ocean taxa relate to state or diet. Candidate autecological eEOVs have not been developed other than for marine mammals and birds. We consider some of the spatial and temporal issues that will influence the adoption and use of eEOVs in an observing system in the Southern Ocean, noting that existing operations and platforms potentially provide coverage of the four main sectors of the region — the East and West Pacific, Atlantic and Indian. Lastly, we discuss the importance of simulation modelling in helping with the design of the observing system in the long term. Regional boundary: south of 30°S.
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Have we so far only seen the tip of the iceberg? Exploring species diversity and distribution of the giant amphipod Eurythenes
- Additional material of the iconic giant amphipod Eurythenes was investigated. Recently, the species E. gryllus has been separated into 12 distinct species-level lineages of which several have been described as distinct species, based on both morphology and genetics. This study revealed three additional species-level lineages from unique sampling localities, showing that with minimal sampling effort, species diversity within Eurythenes can still increase. One species-level lineage was found in the Indian Ocean and another one in the Pacific, which was subsequently identified as E. thurstoni. In addition to the three species already reported from the Southern Ocean (E. maldoror, E. gryllus s.s. and E. andhakarae), a supplementary bathyal species was found in the Weddell Sea. E. gryllus was confirmed to be amphitropical including newly sampled localities around the Kerguelen Islands and additional samples from the Svalbard Archipelago. Building on new and earlier data, geographic and bathymetric distributions of the different species that have been discovered so far are presented here and several factors are evaluated for their likelihood of having triggered past speciation events in this scavenger. Topographic and hydrographical features are discussed but rejected as sufficient reasons for the distributional patterns observed. Bathymetric segregation is interpreted with regard to what is known about the ecology of the species. The previously reported genetic break around 3000 m persists in this new data-set for all species but one. This study underlines the need of processing all individuals sampled, since two or more sympatric species are found in different proportions, and that conclusions regarding diversity and distribution may drastically change when increasing sampling intensity and coverage. Finally, I suggest here that only a mere fraction of all Eurythenes species has yet been discovered and that a more complete knowledge of the ecology of the species is of paramount importance for interpreting their evolution.
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Biomimetic and bio-inspired uses of mollusc shells
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Eerste advies bruinvisonderzoek
