Search publications of the members of the Royal Belgian institute of natural Sciences
-
Spinnen en zware metalen: 2. Contaminatie in enkele spinnensoorten van het Schelde-estuarium.
-
In situ observations of suspended particulate matter plumes at an offshore wind farm, southern North Sea
- Suspended particulate matter (SPM) plumes associated with the monopile foundations of the Belgian offshore wind farm (OWF) Belwind I were acoustically profiled by means of a Doppler current profiler (ADCP). Together with the analysis of a bottom lander dataset of optical and acoustic backscatter sensors (OBSs and ADPs respectively), the spatiotemporal SPM plume dynamics were inferred. The fieldwork comprised (1) near-bed measurements of hydrodynamics and SPM concentrations in the direct vicinity of the wind turbines, by means of a bottom lander over a spring–neap cycle in May 2010; this dataset represents a typically tidedriven situation because there was no significant meteorological forcing during the measurement period; (2) additional vessel-based measurements conducted in May 2013 to capture the SPM plumes inside and outside the OWF over part of a tidal cycle. Both in situ datasets revealed that the SPM plumes were generated at the turbine piles, consistent with aerial and space-borne imagery. The SPM plumes are well aligned with the tidal current direction in the wake of the monopiles, concentrations being estimated to reach up to 5 times that of the background concentration of about 3 mg/l. It is suggested that the epifaunal comunities colonizing the monopile surface and the protective rock collar at the base play a key role as source of the suspended matter recorded in the plumes. The organisms filter and trap fine SPM from the water column,resulting in predominant accumulation of SPM, including detritus and (pseudo-) faeces, at the base of the piles. When tidal currents exceed a certain velocity, fine particles in the nearbed fluff layer are re-suspended and transported downstream in the wake of the piles.
-
NEW FOSSIL HYAENODONTA (MAMMALIA, PLACENTALIA) FROM THE YPRESIAN AND LUTETIAN OF FRANCE AND THE EVOLUTION OF THE PROVIVERRINAE IN SOUTHERN EUROPE
- The proviverrines from the Ypresian (MP7–MP10) and Lutetian (MP11–MP14) are represented mainly by species recorded in the northern and central parts of Europe (Paris Basin, Belgian Basin, Germany, Switzerland). Here, we describe fossils from southern France: Saint-Papoul (MP8 + 9; Aude) and Aigues-Vives 2 (?MP13; Aude). One dentary with secant molars from Saint-Papoul represents a new genus and species, Preregidens langebadrae. This taxon is possibly present in Avenay (France), the MP8 + 9 reference locality. One of the three dentaries discovered in Aigues-Vives 2 belongs to the hypercarnivorous Oxyaenoides schlosseri, previously represented by only two isolated lower molars. This dentary appears to be the most derived of the proviverrines. This species is possibly present in Saint-Martin-de-Londres (France), a locality that is considered to be close to the MP13 reference level. The two other dentaries from Aigues-Vives 2 support the presence of Eurotherium theriodis and provide the first possible evidence of sexual dimorphism in a proviverrine species. A phylogenetic analysis of the proviverrines is performed to resolve the phylogenetic position of the three taxa. This identifies a close relationship between the new genus (Preregidens) and Oxyaenoides. The new fossils allow the age of Saint-Papoul and Aigues-Vives 2 to be refined: the first locality is considered to be close in age to Avenay (Ypresian; France), while the second one seems to be close to Egerkingen c (Lutetian; Switzerland), which is considered to be possibly close in age to the MP13 reference level. Finally, the presence of O. schlosseri and E. theriodis in the southern part of France is compatible with the hypothesis that the mammals involved in the first intra-Eocene turnover migrated northwards.
-
A New Large Hyainailourine from the Bartonian of Europe and Its Bearings on the Evolution and Ecology of Massive Hyaenodonts (Mammalia)
- We describe a new large-sized species of hypercarnivorous hyainailourine–Kerberos langebadreae gen. & sp. nov.–from the Bartonian (MP16) locality of Montespieu (Tarn, France). These specimens consist of a skull, two hemimandibles and several hind limb elements (fibula, astragalus, calcaneum, metatarsals, and phalanges). Size estimates suggest K. langebadreae may have weighed up to 140 kg, revealing this species as the largest carnivorous mammal in Europe at that time. Besides its very large size, K. langebadreae possesses an interesting combination of primitive and derived features. The distinctive skull morphology of K. langebadreae reflects a powerful bite force. The postcranial elements, which are rarely associated with hyainailourine specimens, indicate an animal capable of a plantigrade stance and adapted for terrestrial locomotion. We performed the first phylogenetic analysis of hyainailourines to determine the systematic position of K. langebadreae and to understand the evolution of the group that includes other massive carnivores. The analysis demonstrates that Hemipsalodon, a North American taxon, is a hyainailourine and is closely related to European Paroxyaena. Based on this analysis we hypothesize the biogeographic history of the Hyainailourinae. The group appeared in Africa with a first migration to Europe during the Bartonian that likely included the ancestors of Kerberos, Paroxyaena and Hemipsalodon, which further dispersed into North America at this time. We propose that the hyainailourines dispersed into Europe also during the Priabonian. These migrants have no ecological equivalent in Europe during these intervals and likely did not conflict with the endemic hyaenodont proviverrines. The discovery of K. langebadreae
-
Uncertainty estimation for operational ocean forecast products—a multi-model ensemble for the North Sea and the Baltic Sea
- Multi-model ensembles for sea surface temperature (SST), sea surface salinity (SSS), sea surface currents (SSC), and water transports have been developed for the North Sea and the Baltic Sea using outputs from several operational ocean forecasting models provided by different institutes. The individual models differ in model code, resolution, boundary conditions, atmospheric forcing, and data assimilation. The ensembles are produced on a daily basis. Daily statistics are calculated for each parameter giving information about the spread of the forecasts with standard deviation, ensemble mean and median, and coefficient of variation. High forecast uncertainty, i.e., for SSS and SSC, was found in the Skagerrak, Kattegat (Transition Area between North Sea and Baltic Sea), and the Norwegian Channel. Based on the data collected, longer-term statistical analyses have been done, such as a comparison with satellite data for SST and evaluation of the deviation between forecasts in temporal and spatial scale. Regions of high forecast uncertainty for SSS and SSC have been detected in the Transition Area and the Norwegian Channel where a large spread between the models might evolve due to differences in simulating the frontal structures and their movements. A distinct seasonal pattern could be distinguished for SST with high uncertainty between the forecasts during summer. Forecasts with relatively high deviation from the multi-model ensemble (MME) products or the other individual forecasts were detected for each region and each parameter. The comparison with satellite data showed that the error of the MME products is lowest compared to those of the ensemble members.
-
Cerambycidae attracted to semiochemicals used as lures for Monochampus spp. in the Sonian Forest, Brussels-Capital Region, Belgium (Insecta: Coleoptera)
-
Influence of pesticides, soil temperature and moisture on entomopathogenic nematodes from southern Benin and control of underground termite nest populations
-
High-pressure freezing and freeze-substitution fixation reveal the ultrastructure of immature and mature spermatozoa of the plant-parasitic nematode Trichodorus similis (Nematoda;Triplonchida; Trichodoridae)
-
Rode lijst van de houtbewonende bladsprietkevers. Soorten van holle bomen meest bedreigd.
-
Degraer, S., Vigin, L., Brabant, R., (Eds), 2015. WinMon Activity Report 2013-2014. MARECO report 15/01. 45 pp.
- Wind monitoring Activity report 2013-2014.
-
Degraer, S., Vigin, L., Brabant, R., (Eds), 2015. WinMon Outreach 2005-2015. MARECO report 15/02. 35 pp.
- Windmills monitoring: outreach 2005-2015
-
Sawflies of Ethiopia (Hymenoptera: Argidae, Tenthredinidae)
-
Wave Glider Monitoring of Sediment Transport and Dredge Plumes in a Shallow Marine Sandbank Environment
- As human pressure on the marine environment increases, safeguarding healthy and productive seas increasingly necessitates integrated, time- and cost-effective environmental monitoring. Employment of a Wave Glider proved very useful for the study of sediment transport in a shallow sandbank area in the Belgian part of the North Sea. During 22 days, data on surface and water-column currents and turbidity were recorded along 39 loops around an aggregate-extraction site. Correlation with wave and tidal-amplitude data allowed the quantification of current- and wave-induced advection and resuspension, important background information to assess dredging impacts. Important anomalies in suspended particulate matter concentrations in the water column suggested dredging-induced overflow of sediments in the near field (i.e., dynamic plume), and settling of finer-grained material in the far field (i.e., passive plume). Capturing the latter is a successful outcome to this experiment, since the location of dispersion and settling of a passive plume is highly dependent on the ruling hydro-meteorological conditions and thus difficult to predict. Deposition of the observed sediment plumes may cause habitat changes in the long-term.
-
Backscatter stability and influence of water column conditions: estimation by multibeam echosounder and repeated oceanographic measurements, Belgian part of the North Sea
- The European Union Marine Strategy Framework Directive requires Member States to monitor and assess the health status of their marine habitats. Belgium put forward that the spatial extent and distribution of the major habitats (sandy mud to mud, muddy sands to sands and coarse-grained sediments), as well as that of gravel beds may only fluctuate within a margin that is limited to the accuracy of the current sediment distribution maps. Due to their ability to provide simultaneous bathymetry and backscatter strength (BS), reflecting seabed nature, multibeam echosounder systems (MBES) provide a time- and costefficient solution to anticipate on this legal obligation. However, as there is no formal quality level scale for the BS and consequently no level of reliability of the final decibel values, evaluating the BS quantitative capabilities to monitor habitat changes remains challenging. In a monitoring context, it is absolutely necessary to investigate to what extent the mean MBES-measured BS variation -from one cruise to another- actually represents a significant change in seabed properties and not only a change in the conditions of the water column (e.g., variation in near-bed suspensions, biological effects, increased occurrence of micro bubbles in the sea surface due to wind) at the time of the measurement. In order to evaluate the relative accuracy and the repeatability of MBES BS and to examine the external sources of variance in acoustic signatures, repeated measurements combining MBES with an Acoustic Doppler current Profiler (ADP) have been performed during tidal cycles on reference areas in the Belgian part of the North Sea. Currents and BS in the water column and vertical profiling of oceanographic parameters have been investigated allowing studying the influence of water column conditions on the BS. Measurements were conducted using two MBES systems to evaluate repeatability between echosounders. Ultimate goal is to arrive at seabed mapping and analyses protocols to obtain harmonized data products from a collaborative seabed mapping community.
-
Influence of shells and shell debris on backscatter strength: investigation using modeling, sonar measurements and sampling on the Belgian Continental Shelf
- Acoustic interaction theory and observation highlight the strong relation between the acoustic signal responses and the physical and biological processes acting on the seafloor and in the water column. Several descriptors such as sediment texture, porosity and surface roughness are identified as the main factors affecting the acoustic reverberation and backscatter signals. Shells can influence if not dominate the scattering on the seafloor(Jackson et al., 1986; Stanic et al., 1989 and Zhang, 1996). Scattering from both inclusions and partially buried shells on the sea-floor is described by Stanton (2000), and scattering from shells as a potential mechanism explaining the scattering above 200 kHz is highlighted by Ivakin (2009). In order to improve the knowledge on this matter, several institutions with different expertise are cooperating to integrate mathematical modeling and experimental results to better quantify the influence of shells and shell debris on the acoustic signal and scattering of sonar images. Mathematical 3D models of shell objects in a sediment matrix will be used to simulate the influence of the shells on acoustic signal and scattering. The physical arrangements of shells and their spatio-temporal population trends are also considered in the modeling. The models will be supported by direct sonar measurements of seafloor areas on the Belgian Continental Shelf, combined with sampling, visual observations, classification and shape analysis of the shells and shell debris.
-
Irrigation and human niche construction. An example of socio-spatial organisation in the Zerqa Triangle, Jordan
-
Living in the Burdur Plain. A diachronic reconstrunction of human subsistence (6500 - 200 BC)
-
A narrow place can contain a thousand friends. Irrigation as a response to climate in the Zerqa triangle, Jordan
-
A proposal for a Devonian- Carboniferous boundary based on the Hangenberg extinction event, as suggested by the transition in the Namur-Dinant Basin (Southern Belgium).
-
The orbitally forced sequences of the Lower Tournaisian (Hastarian Substage) of Belgium: Climate reconstruction and time calibration.
