Availability of phosphorus sources for blooms of phaeocystis pouchetii (haptophyceae) in the north sea: Impact of the river rhine

1987 ◽  
Vol 21 (3) ◽  
pp. 219-229 ◽  
Author(s):  
M.J.W. Veldhuis ◽  
L.A.H. Venekamp ◽  
T. Ietswaart
1997 ◽  
Vol 50 (1) ◽  
pp. 77-84
Author(s):  
R. W. Cooper

One of the definitions of Navigation that gets little attention in this Institute is ‘communication by canals and rivers’ (Oxford English Dictionary), and which our French friends call La Navigation. I have always found this subject fascinating, and have previously navigated the Rivers Mekong, Irrawaddy, Hooghly, Indus, Shatt-al-Arab, Savannah and Rhône. During the middle of 1995 I travelled by barge from the North Sea to the Black Sea via the River Rhine, the Rhein—Main—Donau—Kanal (RMDK) and the River Danube, a distance of approximately 4000 km. This voyage has only recently become possible with the opening of the connecting RMDK at the end of 1992, but has been made little use of because of the civil war in the former Yugoslavia.


2009 ◽  
Vol 57 (3/4) ◽  
pp. 253-269
Author(s):  
Gerald Gabriel ◽  
Dietrich Ellwanger ◽  
Christian Hoselmann ◽  
Michael Weidenfeller

Abstract. Since Late Pliocene / Early Pleistocene, the River Rhine, as one of the largest European rivers, has acted as the only drainage system that connected the Alps with Northern Europe, especially the North Sea. Along its course from the Alps to the English Channel the river passes several geomorphological and geological units, of which the Upper Rhine Graben acts as the major sediment trap. Whereas the potential of sediment preservation of the alpine foreland basins is low due to the high dynamics of the system, and the area of deposition close to the North Sea was significantly affected several times by Pleistocene sea level changes, the ongoing subsidence of the Upper Rhine Graben offers a unique potential for a continuous sediment accumulation and preservation.


2010 ◽  
Vol 17 (3) ◽  
pp. 291-293 ◽  
Author(s):  
J. BORCHERDING ◽  
M. HEYNEN ◽  
T. JÄGER-KLEINICKE ◽  
H. V. WINTER ◽  
R. ECKMANN

1991 ◽  
Vol 24 (10) ◽  
pp. 39-43 ◽  
Author(s):  
R. Spanhoff ◽  
J. M. de Kok

A proper management of coastal zones and adjacent estuaries with respect to man-made contaminants requires tools to describe and predict transports of suspended sediments. In a complicated area such as the outflow region of the river Rhine a coherent program of combined field studies and numerical modelling is required to arrive at such tools. Elements of an on-going program are described.


1975 ◽  
Vol 189 (1096) ◽  
pp. 359-374 ◽  

The concentrations of phosphorus and nitrogen compounds in the river Rhine have increased by a factor of about 7 since 1932; in recent years the rate of increase for P has been higher than for N. The concentration of reactive silicate, which is low in summer, has remained essentially constant. Because in the Southern Bight of the North Sea the contribution of nutrients from the deep oceanic reservoir is minor, these increases in riverborne nutrients have had a marked influence on nutrient values and nutrient ratios of the whole area, but especially so on the narrow strip of water along the Dutch Coast, which has an average salinity of 30%ₒ. These changes have caused silicon to be the first depleted nutrient element, limiting diatom blooms. It is shown that the spring bloom of Phaeocystis poucheti is occasionally able to consume all phosphorus, leaving some nitrogen. However, on the average the phosphorus and nitrogen left over by diatoms after all reactive silicate has been depleted is not consumed by other phytoplankton species. In the strip of 30%ₒ salinity water along the coast daily primary production may be up to 3500 mg carbon/m 2 , but yearly primary production is not very high. The vegetative season lasts only about 6 months, due to the influence of turbidity, and is characterized by a succession of periods with high and low productivity. This instability in the phytoplankton regime sometimes causes very high phytoplankton crops and at other times advection and diffusion of unused nutrient loads from the rivers to other parts of the North Sea.


Author(s):  
F. Preusser

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.


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