Rhine River System Research Articles

The Rhine: backbone of Dutch-German economic interdependence 1919–1933

Abstract For a long time, it has been said that Rhine transport plays an important role in Dutch-German economic bonds. Nevertheless, these transport flows have never been the subject of statistical research. This essay aims to fill this gap for the period 1919–1933. To do so, it charts Dutch, German, Belgian and French freight traffic, both by Rhine barge and by train. This essay finds that Germany’s economic structure and international economic ties find a strong expression in the transport sector, with Germany’s economic heartland clearly being the Ruhr area. In fact, the Ruhr area can be identified as the production centre of a transnational economic region formed by the areas that encompass the Rhine river system. Although transport to and from Belgium and France was also concentrated on the (extended) Ruhr area, for both Germany as a whole and the Ruhr area in particular it was transport to and from the Netherlands – where the port of Rotterdam acted as the main distribution centre for this transnational Rhine economy – that was by a large margin the most important. Of all this transport, the vast majority was via Rhine shipping, truly making the Rhine the backbone of Dutch-German economic relations.

Preface

This international workshop on the restoration of fish populations was held as one of the outcomes of the European Life Project ‘Re-introduction of the Allis shad (Alosa alosa) to the River Rhine system’ and was co-organized by the State Agency for Nature, Environment and Consumer Protection of North-Rhine-Westphalia, Germany and the IUCN Specialist groups on ‘Freshwater Fish – Wetlands International’, ‘Re-introduction’, ‘Sturgeons’ and ‘Salmonids’. The key aim of this symposium was to synthesize contemporary knowledge and improve our understanding of the scientific and management needs based on the outcome of recent fish restoration projects while facilitating information exchange of original research results contributed by scientists and managers working in supporting disciplines. The industrial revolution in the late 18th and 19th centuries led to (i) heavy pollution of rivers, lakes and estuaries, (ii) extensive river fragmentation (which is still a growing problem), and (iii) large-scale habitat degradation, resulting into the loss of many populations of native fish species and their supporting habitats. In some countries, several commercially important inland fisheries ceased due to overfishing and severe environmental degradation. The link between poor water quality and fish health together with an increasing awareness by the respective authorities and the public at large of the importance of the natural integrity of the aquatic environment has led to a tightening of the environmental legislation. However improvements in water quality were not seen till the second half of the 20th century. The earliest fish restoration projects were inaugurated in the late 1960s, but soon it became apparent that any effort to restore fish populations is a complex, lengthy and financially costly undertaking. These early attempts to re-introduce and re-establish a species often failed due to an unawareness of the complex environmental and management issues involved (particularly as it pertains to habitat connectivity in rivers), leading to inadequate planning and a subsequent lack of the badly needed resources (financial and otherwise). There was a need for learning by experience. A considerable volume of information and expertise has been gathered over the past 50 years and the workshop provided ample opportunity for discussion by the over 100 experts from 22 different countries. One of the main aims was to facilitate extensive discussions on how to proceed in the future when formulating new project target objectives. As background information, 37 oral contributions and 19 posters were presented which covered a broad range of basic and applied research subjects dealing primarily with fish restoration. A limited number of critically pre-selected contributions to the workshop went through the peer review process and were subsequently prepared for publication. These are presented here in this special supplement volume of the journal. Although the workshop dealt primarily with Shad (Alosa species) and salmonids (Salmo salar), the experiences gained here have wider implications and it is for this reason that a number of authorities and NOGs participated and sponsored this event. We hope that a broader readership will profit from this exercise. We wish to acknowledge the efforts and dedication of numerous colleagues and institutional members who helped locally in organizing the conference. These were: Dr Heiner Klinger, Claudia Brinkmann, Heike El Gamal, Roland Paschmann (all LANUV NRW), Dr Wolfgang Gettmann, Dr Elmar Finke, Marion Wille, Beate Pelzer, Marc Messing (Aquazoo Löbbecke Museum Düsseldorf. Further we wish to thank the scientific committee in preparing and contributing to the science programme: Mark Bain (Cornell University, New York, USA); Jost Borcherding (University of Cologne, Ecological Research Station, Germany); Alain Crivelli (Station Biologique de la Tour du Valat, France); Jaakko Erkinaro (Finnish Game and Fisheries Research Institute, Finland); Jörn Gessner (IGB, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Germany); Detlev Ingendahl (State Agency for Nature, Environment and Consumer Protection in North Rhine Westphalia, Germany); Bror Jonsson (Norwegian Institute for Nature Research, Norway); Heiner Klinger (State Agency for Nature, Environment and Consumer Protection in North Rhine Westphalia, Germany); Arne Ludwig (IZW, Leibniz Institute of Zoo and Wildlife Research, IUCN Sturgeon Specialist Group, Germany); Gordon McGregor Reid (Director North of England Zoological Society, Chair IUCN Freshwater Fish Specialist Group, United Kingdom); Eric Rochard (CEMAGREF, Estuarine ecosystems and diadromous fish unit, France); Pritpal Singh Soorae (Program Officer IUCN Re-introduction Specialist Group, United Arab Emirates); Tom Worthington, University of Southampton, UK. Düsseldorf, September 10, 2011

Temporal progression in migratory status and sexual maturation in European silver eels during downstream migration

The onset of downstream migration of European eels is accompanied by a cessation of feeding and the start of sexual maturation which stresses the link between metabolism and sexual maturation, also suggesting an important role for exercise. Exercise has been tested with eels in swim tunnels and was found to stimulate the onset of sexual maturation. In this study, we have investigated the interplay between migration and maturation in the field during the downstream migration of female silver eels. Temporal changes in migratory status and sexual maturation among silver eels of the upstream Rhine River system over 3 months of the migration season (August, September and October) were determined in biometrical parameters, plasma 17β-estradiol and calcium levels, oocyte histology and gonadal fat levels. Furthermore, the ecological relevant parameters age as determined by otolithometry and health aspects indicated by haematocrit, haemoglobin and swim-bladder parasite load were measured. Silver eels were estimated to be 14 years old. A strong temporal progression in migratory stage was shown over the months of downstream migration. Catches probably represented a mix of reproductive migrants and feeding migrants of which the ratio increased over time. Furthermore, this study confirmed our hypothesis linking the migratory stage to early maturation as indicated by enlargement of the eyes, oocyte growth and fat deposition in the oocytes, exactly the same changes as found induced by exercise but not ruling out environmental influences. Migrants show extensive fat uptake by the oocytes, probably stimulated by the swimming exercise. In addition, at least 83% of the silver eels in this spawning run may have suffered from negative effects of swim-bladder parasites on their swimming performance.

Genetic structure of the vairone Telestes souffia in the eastern part of Lake Constance, central Europe

Examination of the genetic structure of the vairone Telestes souffia based on 10 nuclear markers (microsatellites) revealed little-to-moderate genetic differentiation between geographically adjacent populations in the eastern part of Lake Constance in central Europe. Results emphasize the critically endangered status of this freshwater fish in the upper Rhine River system.

Condition status and parasite infection of Neogobius kessleri and N. melanostomus (Gobiidae) in their native and non‐native area of distribution of the Danube River

AbstractThe success of introduced species is often facilitated by escape from the effects of natural predators and parasites. Introduced species can profit from this favourable situation, attaining higher population densities and greater individual sizes in novel areas. In this study, somatic condition and parasite infection were compared between native and non‐native populations of Neogobius kessleri Günther; introduced only within the interconnected Danube and Rhine River system, and N. melanostomus (Pallas); widely introduced throughout several river systems in Europe and North America. Higher values of Fulton's condition factor were observed in non‐native populations of both goby species. Neogobius melanostomus attained higher gonadosomatic index values in non‐native populations, indicating potential increased investment in reproduction in its new area. A lower splenosomatic index was observed in non‐native populations, especially in N. melanostomus. Parasite infracommunity richness and mean abundance were higher in N. kessleri in both native and non‐native populations, suggesting higher susceptibility of N. kessleri to these parasites. Non‐native populations of both hosts showed higher infra‐community richness as a result of acquiring parasites native to the new area, but lower parasite abundance. Differences in success of the introduction and establishment in new areas between the two fish species may be associated with a relatively low parasite infection rate and a higher gonadosomatic index in non‐native populations of N. melanostomus in comparison to N. kessleri.

Katamysis warpachowskyi Sars, 1877 (Crustacea, Mysida) invaded Lake Constance

The mysid Katamysis warpachowskyi Sars, 1877 originated in the Ponto-Caspian region and the associated river systems. The first evidence of its transgression of the limits of the watersheds of its natural Ponto-Caspian origin was found when three individuals were recorded in October 2009 in eastern Lake Constance (Austria). In March 2010, K. warpachowskyi comprised 10% of the mysid assemblage and was mainly found in rocky habitats. On both sampling dates, breeding females were present. Before this invasion, Limnomysis benedeni Czerniavsky, 1882, was the only mysid in Lake Constance and is also distributed in the Rhine river system. Since the two mysids coexist in Lake Constance, K. warpachowskyi will likely become established in the lake and further expand into the main part of the Rhine. K. warpachowskyi is known as a benthic organism and feeds on detritus and small algae; therefore, the impact on the lake ecosystem should be weaker than that of pelagic mysids.

Fluvial aggradation phases in the Upper Rhine Graben—new insights by quartz OSL dating

The Upper Rhine Graben (URG) is characterized by a thickness of up to 500 m of unconsolidated Quaternary sediments, providing excellent records of the Rhine river system and its responses to tectonic and climatic changes. The most complete Quaternary sequence of fluvial and limnic-fluvial deposits is found in the Heidelberg Basin, due to its long-term subsidence since the mid-Eocene. The aim of this study is to provide a chronological framework using optically stimulated luminescence (OSL) dating of aeolian and fluvial sands derived from the upper 33 m of a sediment core, which was drilled into the Heidelberg Basin infill close to the village of Viernheim, Germany. The OSL ages demonstrate that the dated fluvial sediments were deposited during the last glacial period (Weichselian) and that there were at least three aggradation periods during this episode. The coversands that cap the sequence were emplaced during the early Holocene.

Genetic and ecological impacts of heavy metal and flooding stress on the earthworm Lumbricus rubellus in floodplains of the Rhine river

In the highly polluted river Rhine system, earthworms face environmental stress resulting from flooding and elevated heavy metal concentrations in the floodplain soil. Previous field studies have revealed adaptation to flooding for the earthworm species Lumbricus rubellus as this species matures at a lower weight in floodplain sites with a high frequency of flooding compared to less frequently flooded sites. Also heavy metals have effects on L. rubellus and heavy metals are influencing the genetic composition of this species. In this study, it was tested whether flooding and heavy metals had an impact on the genetic composition of L. rubellus living in floodplains along the river Rhine system. Earthworms were sampled at three sites previously studied along the river to assess earthworm diversity, biomass, density, and individual weight, and developmental status of L. rubellus. The genetic variation by means of isozymes was studied for 175 individuals. The results showed lowest density of L. rubellus adult and sub-adult life-stages and lowest individual weight of these life-stages at the frequent inundated site. The genetic composition, however, showed no effects of flooding on the genetic composition, but effects of heavy metals could not be ruled out.

Population genetics of a cyclostome species pair, river lamprey (Lampetra fluviatilis L.) and brook lamprey (Lampetra planeri Bloch)

Horizontal agarose gel electrophoresis of 24 allozyme loci in four species of Central European lampreys (321 Lampetra planeri, 83 L. fluviatilis, 11 Eudontomyzon mariae and nine Petromyzon marinus) was used to study the ‘paired species’L. fluviatilis and L. planeri. The genetic differentiation of the anadromous river lamprey (L. fluviatilis) from the stationary brook lamprey (L. planeri) was within the range of ingroup differentiation of the latter, but L. fluviatilis exhibited much greater population cohesion over a more extended geographic range: GST = 0.0537 versus GST = 0.3398, Nem = 4.402 versus Nem = 0.4856, mean genetic among-stock distances D = 0.0047 versus D = 0.0257. L. planeri populations coexisting geographically with L. fluviatilis in the Rhine and Elbe river systems were genetically more cohesive than L. planeri stocks from the Danubian basin where L. fluviatilis is absent. Danubian L. planeri populations exhibit a lower degree of heterozygosity than brook lampreys from the Rhine river system, but comprise deeper genetic lineages (GST = 0.4629 versus GST = 0.2434), despite being sampled from a much more restricted area. Isolation-by-distance is observed for L. planeri from the Danubian but not from the Atlantic drainage basins. Transspecific gene flow between L. planeri from Atlantic drainage basins and the long-distant migrating L. fluviatilis is inferred, raising doubt on the validity of two separate biospecies. E. mariae and P. marinus are clearly differentiated from Lampetra spp. at several allozyme loci.

Provenance of basalt blocks from Roman sites in Vleuten-De Meern (the Netherlands) traced to the Tertiary Siebengebirge (Germany): a geoarchaeological quest using petrological and geochemical methods

AbstractUnshaped basalt blocks from archaeological sites along the border of the Roman Empire (limes) in the lower Rhine area near Vleuten-De Meern (Utrecht) have been studied petrographically, analysed by XRF for major and trace elements, and dated by the 40Ar/39Ar method. The blocks are from a revetment in the bank of a fossil branch of the Rhine and a contiguous ship De Meern 4, both built around 100 AD. All nineteen blocks are alkali olivine basalt (AOB) with xenoliths of peridotite derived from the upper mantle and quartz xenocrysts from the continental crust; eighteen blocks contain resorbed plagioclase xenocrysts as well. Abundances of major and trace elements show that those eighteen samples form a chemically coherent group. The outlier, different in chemistry and without plagioclase xenocrysts, is from the ship. A basalt block from ship De Meern 1 (148 AD) conforms compositionally to the defined group. AOB lumps from a limes watchtower (2nd-3rd century) form a chemically distinct group.Low SiO2 contents (<46 wt.%) and high abundances of Mg, Ti, Ni, and Sr indicate a within-plate origin, directly from primitive melts; proportions of selected trace elements point at a continental rift setting. In the archaeological context, the most likely source region for the blocks is the Cenozoic European Volcanic Province, upstream along the Rhine and its tributaries.The petrographic and analytical data of the blocks have been compared with 432 published analyses of German AOB. On petrographic grounds, the Eifel can be ruled out as a source area since typical Eifel basalt minerals, amphibole, biotite, K-feldspar and feldspatoids, are absent in the blocks. Applying seven geochemical criteria, based on abundances of major elements in the Roman blocks, twelve sites with matching AOB were found in the Siebengebirge, seven in the Vogelsberg, and one in the Westerwald.The ages of the blocks (26.3 - 28.5 Ma) are compatible with ages determined for AOB from the Siebengebirge (27.4 - 29.9 Ma), and preclude their provenance from the Vogelsberg (< 18 Ma). The matching Westerwald sample is from 60 km beyond the limes, a prohibitive distance from the perspective of Roman logistics.AOB quarries of optimal logistic position are located adjacent to the Rhine, between Bonn and Remagen, a zone with significant Roman settlements from the first century AD. Geochemical correlation indicates AOB bodies at Rolandsbogen and Godesburg (S of Bonn) as potential sources of the blocks from the 100 AD revetment and ships. Similarly, the Erpeler Ley (E of Remagen) is indicated as the likely source for the blocks from a 2nd-3rd century AD watchtower.As the Godesburg basalt is at 1.6 km from the Rhine today, it is not obvious how the blocks were transported from there. However, it may be that the adjacent, now sanded, branch of the old Rhine river system, was navigable for flat-bottomed vessels in Roman times.Our study demonstrates that substantial detailed information regarding ancient mining and trading activities can be retrieved from seemingly indistinctive basalt blocks.

Invasion phylogeography of the Ponto‐Caspian crustacean Limnomysis benedeni dispersing across Europe

ABSTRACTAim Limnomysis benedeni Czerniavsky, 1882 is a mysid crustacean native to the Ponto‐Caspian (Black and Caspian Sea) rivers and estuaries, and has recently spread across Europe through intentional and unintentional introductions. We explored the structuring of genetic variation in native and non‐native populations with an aim to trace the sources of the invasions, and to infer whether the spread has occurred through a single or multiple invasion waves.Location Native estuaries in the Ponto‐Caspian basin (Volga, Don, Dnieper, Dniester, Danube) and the recently colonized range along the Danube–Rhine river systems and Lithuania.Methods A fragment of the mitochondrial COI gene was sequenced to assess genetic affinities and diversity in native and recently established populations.Results The genetic diversity in the native regions is organized into several strongly diverged haplotype groups or lineages, partly allopatric, partly sympatric. All these lineages have also spread beyond the native range. Even the recent rapid dispersal across Europe along the Danube–Rhine system towards the North Sea basin involved several lineages from the Danube delta sector. The structuring of genetic diversity among invaded sites suggests multiple invasion events to the Danube–Rhine drainage. This contrasts with data from some other Ponto‐Caspian species, where a single haplotype seems to have occupied most invaded areas. There is no evidence that intentionally stocked reservoirs in the Baltic Sea basin would have contributed to further unintentional spread of L. benedeni.Main conclusions Limnomysis benedeni is spreading across Europe using the southern invasion corridor. The invasion most likely involved several waves from differentiated sources in the native Danube delta area.

The confluence area of Rhine, Meuse, and Belgian rivers: Late Pliocene and Early Pleistocene fluvial history of the northern Lower Rhine Embayment

AbstractThe fluvial history of the northern Lower Rhine Embayment shows interplay of three main river systems: Rhine, Meuse and smaller rivers draining the central and northern part of Belgium.The Pliocene and Early Pleistocene (pre-)Rhine and Meuse river systems had their conjunction in the southern part of the Roer Valley Graben between Aachen and Jülich. Despite slight differences in the heavy-mineral assemblages the lithological composition of the Pliocene deposits of the three river systems shows close resemblance and therefore they cannot be mapped separately. However, due to a marked change of the petrographical composition the Upper Pliocene and Lower Pleistocene deposits of the Rhine are easily recognised and as a result Rhine and Meuse deposits can be mapped separately upstream of their confluence.The Lower Pleistocene deposits of Rhine, Meuse and the Belgian rivers show a clear interrelationship. They are bounded by two regional well-mapable unconformities and are preserved in from west to east changing lithostratigraphical sequences. Revision of the lithostratigraphical schemes in Germany and the Netherlands and the better defined lithostratigraphical position of Meuse deposits in Germany now strongly constrain the correlation of the various fluvial deposits. As a result existing reconstructions of the fluvial deposition and tectonic history of the southern Roer Valley Graben can be evaluated and re-adjusted.It is concluded that the main course of the Meuse was aligned through the so-called East Meuse valley during the larger part of the Early Pleistocene. Available pollen data do not conflict with this conclusion. At the same time the Rhine ceased to enter the southern part of the Roer Valley Graben. Instead, the Meuse accumulated here a series of deposits derived from the East-Meuse valley. Simultaneously, the Belgian rivers filled available accommodation space in the Roer Valley Graben of the southern Netherlands. The conclusions are based primarily on the revised lithostratigraphical framework. In general they simplify the picture of fluvial and tectonic behaviour of the area.

The Rhine - a major fluvial record

AbstractThis special issue contains the papers presented during the 2004 DEUQUA meeting. The papers provide an overview of recently carried out Quaternary geological studies on different aspects of the river Rhine system. The introductory paper follows the pathway of the Rhine downstream from its source in the Swiss Alps to the delta in the Netherlands. Along this route geological and geographical factors determine the regional subdivisions of the river: the Alps, the Upper Rhine Graben, the Rhenish Massif, and the Lower Rhine Embayment as part of the southern North Sea Basin. Each of these regions can be typified by a characteristic geological evolution.New evidence from heavy-mineral analyses provides an improved lithostratigraphy and insight in the Quaternary evolution of the Rhine in the Upper Rhine Graben. The Plio-Pleistocene transition is determined by a palaeomagnetic study. The same paper emphasis on the impact of climate change on the composition of the magneto-mineralogy. Pollen analytical results show a complex interrelationship of a number of Middle Pleistocene interglacial periods in the northern part the Upper Rhine Graben. In the same area geomorphological analysis demonstrates a clear influence of tectonics on the preservation of fluvial terrace accumulations. A detailed pollen analytical study on the Late Glacial and Holocene development of the Rhine in the northern Upper Rhine Graben discusses the relation between vegetation cover and river behaviour. Finally, two papers from the Lower Rhine Embayment discuss a revised provenance based lithostratigraphy and its implications for understanding the fluvial history.

Characterisation and evolution of the River Rhine system

AbstractThe River Rhine and its tributaries represent one of the largest drainage systems in Europe. Its prominence among other fluvial systems is due to the location of its headwaters within the central Swiss Alps, which were repeatedly glaciated during the Quaternary, and the concurrence of major parts of the River Rhine course with the European Cenozoic Rift System. Sediments of the Rhine have thus recorded both changes in climate and tectonic activity as well as sea level change in the lower part of the river course.The River Rhine is composed of different subdivisions characterised by distinct geographical and geological settings. Vorder-and Hinterrhein in the headwaters are inner-alpine rivers frequently influenced in their course by tectonic lines and the blockage of valley floors by the deposits of mass movements. The Alpenrhein is located in a main Alpine valley that drains into a large foreland basin, the Bodensee (Lake Constance). The Hochrhein flows out of the lake following the Jura Mountains in a western direction. All these areas display a series of geological features such as moraine ridges and outwash plains, which directly reflect Quaternary glaciations of the Alps. The Oberrhein (Upper Rhine) Valley, as a graben structure, is part of the rifting system that started to develop during the middle Tertiary. The northern end of the graben is represented by the triple junction of the Mainz Basin, which is mainly characterised by the remains of marine transgressions that occurred during the initial rifting phase. The Rhine continues following the western branch of the tectonic system by passing through the Rhenish Massif. Uplift in this so-called Mittelrhein (Middle Rhine) area is well documented by a flight of late Tertiary to Quaternary river terraces. This region is also characterised by young volcanic activity as found, for example, in the Eifel volcanic field. The Niederheinische Bucht (Lower Rhine Embayment), especially the Roer Valley Rift System, represents the northern continuation of the rifting system. This area is characterised by differential uplift in the southern and subsidence in the northern part of the basin, which continues into the Netherlands. Here, the main stream of the River Rhine is separated into different branches developing an active delta at the coast of the North Sea. When the North Sea Basin was covered by ice during the Elsterian, Saalian and probably also the Weichselian glaciation and global sea level was low, the Rhine continued its course through the English Channel and flowed into the North Atlantic off Brittany.

Do eel parasites reflect the local crustacean community? A case study from the Rhine river system

In 2003, the parasite fauna of 197 European eels Anguilla anguilla, captured at three different locations (Laufenburg, Karlsruhe and Beneeden Leeuwen) in the River Rhine, was analysed. The eels harboured a total of 18 species, among them the protozoa (Myxidium giardi, Myxobolus kotlani and Trypanosoma granulosum), acanthocephalans (Acanthocephalus anguillae, Acanthocephalus lucii, Echinorhynchus truttae, Pomphorhynchus laevis), nematodes (Paraquimperia tenerrima, Pseudocapillaria tomentosa, Camallanus lacustris, Raphidascaris acus, Spinitectus inermis and Anguillicola crassus), cestodes (Bothriocephalus claviceps and Proteocephalus macrocephalus) and monogeneans (Pseudodactylogyrus sp.). The parasite fauna at the different locations is discussed with respect to the crustacean fauna present at these locations. The investigation shows that changes in the composition of the crustacean fauna, due to the anthropogenic breakdown of a biogeographic barrier, are reflected in the composition of the intestinal eel parasite fauna.

Continued massive invasion of Mysidae in the Rhine and Danube river systems, with first records of the order Mysidacea (Crustacea: Malacostraca: Peracarida) for Switzerland

Continued massive invasion of Mysidae in the Rhine and Danube river systems, with first records of the order Mysidacea (Crustacea: Malacostraca: Peracarida) for Switzerland

Trends in flood stages: Contrasting results from the Mississippi and Rhine River systems

An obstacle to testing human impacts on flooding is that anthropogenic and natural hydrologic changes occur simultaneously and are often indistinguishable. We attempted to isolate the impacts of overlapping mechanisms on flooding by analyzing 73-188 years of stage measurements from the Mississippi River system and the German Rhine. Although typically under-utilized in hydrologic analysis, stage data document the cumulative impacts of both upstream changes such and climate and land use as well as modifications of the river channel and floodplain. Analysis of trends in peak stages and flood frequencies shows contrasting results on the Mississippi and Rhine: increasing trends at most Mississippi stations, but no significant trends at most Rhine stations. On the Mississippi and its tributaries, statistically significant changes in peak stages and peak-stage frequencies were identified at 10 of 14 stations, with all but one exhibiting increased flooding. On the Rhine River, systematic change occurred at only 1 of 8 stations analyzed. On both river systems, channel and floodplain modifications dominated net hydrologic response, overwhelming the effects of climate change, land-use shifts, and dam construction. Specific-gage analysis, which isolates the impacts of instream river modifications, documented declining flow conveyance at all stations where flood levels and frequencies increased. Increased flooding at the Mississippi River sites appears to be driven by the history of aggressive channel engineering, in particular channel constriction to increase navigation depths. In contrast, navigation infrastructure on the Rhine has not substantially degraded the river's capacity to efficiently convey flood flows.

A genetic map ofCottus gobio(Pisces, Teleostei) based on microsatellites can be linked to the physical map ofTetraodon nigroviridis

To initiate QTL studies in the nonmodel fish Cottus gobio we constructed a genetic map based on 171 microsatellite markers. The mapping panel consisted of F1 intercrosses between two divergent Cottus lineages from the River Rhine System. Basic local alignment search tool (BLAST) searches with the flanking sequences of the microsatellite markers yielded a significant (e < 10(-5)) hit with the Tetraodon nigroviridis genomic sequence for 45% of the Cottus loci. Remarkably, most of these hits were due to short highly conserved noncoding stretches. These have an average length of 40 bp and are on average 92% conserved. Comparison of the map locations between the two genomes revealed extensive conserved synteny, suggesting that the Tetraodon genomic sequence will serve as an excellent genomic reference for at least the Acanthopterygii, which include evolutionarily interesting fish groups such as guppies (Poecilia), cichlids (Tilapia) or Xiphophorus (Platy). The apparent high density of short conserved noncoding stretches in these fish genomes will highly facilitate the identification of genes that have been identified in QTL mapping strategies of evolutionary relevant traits.

Modeling of the Solid−Solution Partitioning of Heavy Metals and Arsenic in Embanked Flood Plain Soils of the Rivers Rhine and Meuse

The aim of this study is to predict the solid-solution partitioning of heavy metals in river flood plain soils. We compared mechanistic geochemical modeling with a statistical approach. To characterize the heavy metal contamination of embanked river flood plain soils in The Netherlands, we collected 194 soil samples at 133 sites distributed in the Dutch part of the Rhine and Meuse river systems. We measured the total amounts of As, Cd, Cr, Cu, Ni, Pb, and Zn in the soil samples and the metal fraction extractable by 2.5 mM CaCl2. We found a strong correlation between heavy metal contamination and organic matter content, which was almost identical for both river systems. Speciation calculations by a fully parametrized model showed the strengths and weaknesses of the mechanistic approach. Cu and Cd concentrations were predicted within one log scale, whereas modeling of Zn and Pb needs adjustment of some model parameters. The statistical fitting approach produced better results but is limited with regard to the understanding it provides. The log RMSE for this approach varied between 0.2 and 0.32 for the different metals. The careful modeling of speciation and adsorption processes is a useful tool for the investigation and understanding of metal availability in river flood plain soils.

Appearance and technological characteristics in wild and reared Eurasian perch, Perca fluviatilis (L.)

The purpose of this study was to characterize some quality descriptors of wild Eurasian perch, Perca fluviatilis, taking into account spatial and temporal variability and to situate quality in reared perch in comparison with wild perch variability. Two different natural systems (Léman Lake and the Rhine River) were selected to characterize perch quality variability during an entire biological cycle. Farmed perch quality was studied in relation to the rearing system (extensive, semi-extensive and intensive systems). Using the morphometric, technological and color descriptors, it was shown by Principal Components Analyses (PCA) that in the Rhine River, fish had compact body and caudal fin, large mouth and head and possessed a more reddish caudal fin, in comparison to fish from Léman Lake that are brighter. Seasonal variations were different according to the natural system. In the lacustrian system, fish presented low seasonal variations contrary to the Rhine River system for morphometric and color variables. The technological attributes showed the highest degree of seasonal variation, e.g. fillet yield was high in July. These technological variables were found as being the main discrimination way between fish from the different rearing systems. The intensive rearing system produced perch with higher hepatosomatic index ( I H) and perivisceral fat index ( I PF) compared with the extensive and semi-extensive rearing systems. Moreover, the more intensive rearing conditions were, the more fat deposits increased. It was also found that reared perch possessed wild-like quality characteristics, except for some technological variables (viscerosomatic index: I V and fillet yield: Y F). Furthermore, perch from the semi-extensive system had the most similar quality attributes with fish from the Rhine River. Thus, morphology and color (i.e. color of caudal fin) appeared to be pertinent quality descriptors for wild fish, whereas technological attributes were more adequate for the characterization of reared fish quality. This study also suggested some hypothesis about the direct or indirect relationships between abiotic factors, such as chemical water characteristics, transparency, temperature and quality attributes.