2020 Salmon - Conservation Corridor
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Rhine
Salmon 2020
Internationale
Kommission zum
Schutz des Rheins
Commission
Internationale
pour la Protection
du Rhin
Internationale
Commissie ter
Bescherming
van de Rijn
Auf Perlen schäumenden Weines
Herzliebchen trag’ ich dich fort,
Fort zu den Ufern des Rheines,
Dort weiß ich den schönsten Ort.
Dort siehst eine Insel Du ragen
Im hellen Mondenschein,
Die Pfalz die tut sie tragen, Publisher:
Dort wandern wir dann zu zwei’n. International Commission
…
for the Protection of the Rhine (ICPR)
Es schwimmen herbei und lauschen
Die Salme, die leckern Gesell’n,… Postfach 20 02 53
D-56002 Koblenz
„Herzliebchen in der Pfalz”
Heinrich Heine (1824)
Tel.: +49-(0)261-94252-0
Fax: +49-(0)261-94252-52
E-mail: sekretariat@iksr.de
Internet: www.iksr.org
Editor:
Dr. Anne Schulte-Wülwer-Leidig
Scientific advice:
Dr. Jörg Schneider
and ICPR fisheries experts
Author:
Barbara Froehlich-Schmitt
Translation:
K. Wehner
Title photo:
LMZ,ASR, B. Stemmer, G. Feldhaus,
U. Haufe, S. Staas
Design and production:
AD DAS WERBETEAM GMBH
www.ad-werbeteam.de
ISBN: 3-935324-51-0
Photo: LMZ, H.P. Merten
Print run: 2.000
Copyright:
ICPR- 2004
The island Pfalz near Kaub in the Middle Rhine
Rhine & Salmon 2020
A Programme for Migratory Fish in the Rhine System
Summary 4
Map of projects 5
Introduction 6
Vision of wild salmon in the Rhine 6
Target biological diversity 7
The history of salmon fishery 8
Salmon life cycle 9
1. Secure nursery grounds 10
The demanding children of the salmon 10
Inventory of juvenile fish habitats 11
Future salmon populations 12
Habitat measures 13
2. Open migration routes 14
Rhine delta 15
Lower Rhine 15
Middle Rhine 16
Upper Rhine 17
High Rhine 17
3. Release juvenile fish 18
Table of salmon stocking exercise 19
Rhine delta 20
Lower Rhine 20
Middle Rhine 20
Upper Rhine 20
High Rhine 21
4. Success control 22
Monitoring stations 22
Diversity of migratory fish 23
Downstream migration 25
Returning from the ocean 26
Natural reproduction 27
Assessment and Conclusion 28
Bibliography 30
3
Summary
"Salmon 2000" and its successful actions in favour of migratory fish is
being continued in the 21st century. It is part of the new ICPR working
programme "Rhine 2020”. So visions can become true:
1st vision: 3rd vision:
Several thousands of Salmon stocking is
salmon in the Rhine self-sustaining
The list of suitable salmon habi- During the past five years, some
tats in the Rhine tributaries has 11 million juvenile salmon have
become considerably longer. been released into the Rhine
Therefore, the hope of the ICPR catchment. Partly, they are the
to achieve a larger salmon popu- descendants of adult returning
lation than what was calculated salmon.
only five years ago, seems to be
justified. Careful estimate: 7,000
to 21,000 salmon annually 4th vision:
migrating upstream. Wild salmon in the
Rhine in 2020
2nd vision: The return of salmon from the
Undisrupted salmon ocean and, above all, their natu-
migration as far ral reproduction prove the
as Basel success of this programme. Since
1990, evidence has been given
Since 2001, three new fish of more than 2400 adult salmon
passages have been opened in returning and migrating up-
the Rhine delta. Numerous weirs stream the Rhine system. More
have been changed or lowered than 300 of them used the new
in the tributaries to the Lower, fish passage at Iffezheim, 700 km
Middle, Upper and High Rhine. upstream the estuary.
On the Upper Rhine, the
Iffezheim fish passage was put Rhine salmon are not yet inde-
into service in 2000. In 2006, the pendant of human help and
second huge fish passage will stocking exercises. But they
open its gates at Gambsheim. already reproduce naturally in
several tributaries to the Lower,
Middle and Upper Rhine. This
raises hopes that stable wild
salmon populations may be
achieved in the Rhine system by
the year 2020.
4
Map of projects
IJssel
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ba
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Sa
e
sell
Sa
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Mo
5
Introduction
This brochure is published five
years after the International
Rhine Symposium in Rastatt and
the brochure "Has the Rhine
again become a Salmon carrying
River”. In 1999, conclusions
were: The Rhine Action Pro-
Photo: ASR Strasbourg
gramme and "Salmon 2000”
prove to be a great success and
have reached the target to en-
able migratory fish such as the
salmon to return to a restored Atlantic salmon (Salmo salar)
Rhine (ICPR reports 102 +103, 1999).
A vision of wild ments of the EU Water Frame-
salmon in the Rhine work Directive (WFD) into con-
AThe
vision of returned,
salmon has wild but it is crete terms. Its objective is to
still hiding. We want it to be We must now head for a new, achieve the good ecological sta-
abundant, as a source of joy! demanding target, which is the tus of all rivers or the maximum
Mrs Perrin-Gaillard / Deputee development of stable Rhine environmental potential in case
from Paris, Rhine Symposium 1999 of heavily modified water bodies.
salmon populations capable of
natural reproduction and mainte- Further pan-European regula-
nance of stock without any tions, such as the Flora-Fauna-
stocking exercise or other human Habitat (FFH) directive help pre-
help. The ICPR work programme serve and develop natural
Rhine 2020 puts the require- aquatic ecosystems.
EU water framework directive
focuses on biological indicators
defines the good ecological status
Photo: H. Stolzenburg
fixes 2015 as deadline for achieving the good status in
all European water bodies
Rhine Symposium in Rastatt, 1999
Targets Rhine 2020
Restore the habitat patch connectivity
Ecological patency of the R. Rhine from Lake Constance to the North Sea
as well as of the tributaries listed in the programme on migratory fish.
The great enthousiasm for IKSR (2001) p. 12
Salmon 2000 in Switzerland,
France, Germany, Luxemburg
and right up to the Netherlands
has made the programme to a
success story
Anne Schulte-Wülwer-Leidig (2000)
6
Photo: Wolfram Gonitz
Old bed of the Rhine
Ta rg e t : b i o l o g i c a l d i v e r s i t y a l o n g t h e R h i n e
So the programme Rhine 2020 e.g. sea trout, allice shad and
looks at the biological diversity of river lamprey but also great
the Rhine system. Apart from the crested grebe and kingfisher,
salmon, the target species within beaver and otter as well as water
this programme are the many nut and water fringe, because all
typical plants and animals which actions targeted at protecting
formerly or today colonize the and renaturing the Rhine river
Rhine Salmon 2020
river, its tributaries and alluvial ar- system enhance its natural
Actions
eas. Other migratory fish species biological diversity.
1. Restore habitats
swim in the wake of the salmon, 2. Activate floodplains
3. Improve river structure
4. Remove obstacles to free
Targets of the Flora-Fauna-Habitat (FFH) directive migration and develop a
Implement the Rio de Janeiro Convention on biological subnatural network of
diversity of 1992 habitats
Protect European natural heritage
Preserve endangered plant and animal species within a network of
strictly protected areas = NATURA 2000
Directive 92/43/EEC
Species protected according to the FFH directive,
e.g.:
Atlantic salmon (and other migratory fish)
river pearl mussel
yellow-bellied toad
beaver
otter
Otter
Photos: Manfred Delpho, www.delpho.de
Kingfisher Great crested grebe
7
Reproduction: Baldner, 1666
Salmon taken from Geßner
The Salmon
T h e h i s t o r y o f s a l m o n f i s h e r y. . . In Siberia, Russia and Scandinavia
the salmon is of great importance for
along the Rhine goes right back and the biggest salmon river in public nourishment; for us, it is rather
to Roman times, some 2000 Europe and salmon belonged to considered to be a delicacy (Rhine
salmon) and is sold fresh, smoked and
years ago. As late as the 18th staple food. But massive stocking
soused.
century, the R. Rhine was consid- exercises began as early as the Meyers Encyclopedia, vol. 10,
Leipzig and Vienna (1895)
ered to be the most important 19th century and an internation-
al salmon treaty was passed, tar-
Due to poor water quality in the
geted at “increasing the stock of
lower course of the Rhine, the In-
salmon in the Rhine area” (Reichs-
ternational Commission for the
amt 1886). Since mill weirs ob-
Protection of the Rhine (ICPR)
structed the access to numerous
was then founded. Following
spawning areas, fishermen
the fire of the Sandoz warehouse
demanded the construction of
near Basel and the resulting
“salmon ladders”.
great fish kills in 1986, the effica-
cy of the ICPR and its Rhine Ac-
The pollution of the Rhine with
tion Programme as well as the
domestic and industrial waste
projects for migratory fish
water started to be a problem in
”Salmon 2000” was enormous.
the 19th century and culminated
in the mid 20th century. Rhine
salmon died out in the 1950s.
Landmarks Rhine salmon + ICPR
1986 The disastrous chemical accident in Basel caused fish and invertebrate kills as far
downstream as the Lower Rhine
1987 The reply of the ICPR is the Rhine Action Programme or Salmon 2000
1990 The first salmon migrates from the sea into the Lower Rhine and further into the R. Sieg
1991 The ICPR drafts the Ecological Master Plan and a Programme for Migratory Fish
1994 First natural salmon reproduction in the R. Sieg system / Lower Rhine
1995 The first salmon reaches the Iffezheim barrage on the Upper Rhine
1997 First natural salmon reproduction in the Alsacian Ill river system
1999/2000 First salmon redds in the R. Ahr and Saynbach / Middle Rhine
2000 Iffezheim fish passage and monitoring station put into service
2000 Opening of the control station Buisdorf on the R. Sieg
2000 EU Water framework directive (WFD) comes into effect
2000 Rhine 2020 – Programme on the sustainable development of the R. Rhine adopted
by Rhine Ministers
8
Salmon life cycle
Sea
Growth period
Reproduction
Smolt
Parr
River
The life cycle
of Atlantic salmon...
starts in spring, when the larvae on their way upriver. They travel Eggs are fertilized by big salmon
are hatched from the chorion until they reach the confluence with hooked jaws keeping a jeal-
dug deep into the gravel bed of of their "home” tributary where ous eye on the procedure and, in
limpid brooks in Europe and they leave the main channel and some cases, by jacks. These are
North America. As long as the continue upriver. Most natural only 10 to 20 cm long, preco-
alevins feed on their yolk sack, obstacles, such as rapids and cious males dashing out of their
they avoid daylight and are large- smaller waterfalls do not obstruct hiding places and spreading their
ly immobile. Later they wriggle their migration. Thus they gain milt into the redd. In many cases,
up from the gravel bed and the upper reaches of the river half of the hatching breed de-
search for suitable habitats in the where they once hatched, a cool scends from a precocious father.
shallow parts of the river. They and limpid brook with a gravel Most salmon die after spawning.
feed on microscopic life in the bed. That is where they engage A salmon life cycle ends and after
stream and grow to spottet parr. in courtship in the fall of the year. four months in the river gravel
After 1 or 2 years they leave the While females dig several meter bed a new cycle starts the follow-
river as 12-20 cm long silvery wide redds into the gravel bed, ing spring.
smolts and gain the sea. In the males fight for the best places.
Atlantic Ocean they travel to the
feeding grounds around Green-
Different stages in the lives of salmon and sea trout
land, where they feed on crus-
taceans and smaller fish and Alevin Feeding off yolk sack (after hatching, before being able
grow rapidly. Multi sea winter to feed independently)
salmon having spent several win- Fry The first weeks after feeding off yolk sack
ters in the ocean may weigh Parr Juvenile fish, 1 to 3 years old with lateral parr marks
more than 10 kilos and grow to a Jacks Precocious parr
size of 80 to 100 cm. As they be- Smolt Juvenile fish between the age of 2 and 4 years,
come mature, they return over mostly migrates downstream in the spring
thousands of kilometres from the Grilse Small adult salmon returning to its natal river after 1 winter at sea,
which is often the case with salmon and, above all, sea trout
Atlantic Ocean back to the estu-
MSW "Multi-Sea-Winter", big returning adult salmon with more than
ary of their natal river and mi- 1 (often 2-3) winter(s) ocean residence
grate upstream. Kelt Fish that has spawned, dies in most cases
It is believed that it is above all
(HUMBORG 1990, LE CREN 1985, PEDROLI 1991)
the smell which guides salmon
9
Rhine 2020
1
Ecosystem improve-
ment
Secure nursery grounds by protecting and revitalizing in-
tact salmon spawning grounds,
juvenile habitats and suitable fish
habitats
in the main stream
in tributaries included in
the programme on migratory
fish
IKSR (2001) p. 13
Juvenile salmon require a great
habitat diversity. During the sum-
mer they live in the shallow
gravely parts of the river offering
Photo: ASR Strasbourg
Photo: Gerhard Feldhaus
much shelter, e.g. stones off the
river banks. In autumn, young
salmon colonize deeper areas
with less current. This is when
precocious males head down- Salmon redd
stream, awaiting the females re-
Salmon alevin feeding from yolk sack
turning from the ocean!
Photo: U. Haufe
C h i l d re n o f s a l m o n
a re d e m a n d i n g
Young salmon in the Steinchesbach/Bröl
Salmon only successfully repro-
duce in rivers with clean, cool
water rich in oxygen. They prefer
the so called hyporhitral, the low-
er salmonid region of mountain
rivers also called the grayling
zone after its key indicator
species, and the metarhitral, the
lower trout region. Natural, unal-
Foto: Frank Molls
tered rivers and brooks with high
flow velocity are most suitable,
since they are de-silted by natural
flow dynamics and floods create Typical juvenile salmon habitat
new gravel beds, scours and
shelters.
Foto: Bernd Stemmer
The grayling is the key indicator species of juvenile salmon habitats
10Inventor y of
juvenile habitats
Formerly, salmon migrated up
the main channel until they
reached the falls of the Rhine
near Schaffhausen. They used to
spawn in the southern Upper
Rhine as well as in the High
Foto: BFS Schneider
Rhine. Since the Upper Rhine has
been dammed, the Franco-Ger-
man old bed of the Rhine is the
only river section with consider- Salmon habitat in the R. Nister
able spawning habitats. Even
though there are barrages in the From the High Rhine the salmon ing salmon and sea trout. Today,
High Rhine, there are still two un- migrated into the right bank several additional river sections
obstructed sections suitable for tributary Wiese, into the left bank are considered to be suitable.
fish spawning in gravel beds. tributaries Birs and Ergolz and The sections concerned are parts
via the R. Aare into many pre- of the tributaries to the Lower
Most of the historically proven alpine tributaries, 1.200 km Rhine Wupper with its tributaries
salmon spawning habitats were upstream the Rhine estuary. Dhünn, Ruhr with Volme and
located in the Rhine tributaries Upper Rhine tributaries from the
and their tributaries from the up- Mapping of juvenile habitats Black Forest, such as Alb and trib-
lands to the pre-alpine regions. During the last 15 years, inten- utaries to the rivers Murg, Rench,
The Lower Rhine tributaries Ruhr, sive investigations were made in- Kinzig and Elz figuring in the
Wupper and Sieg from the Ber- to which rivers are apt for carry- programme.
gisches Land, the Sauerland and
Siegerland were already consid-
Section of Tributaries Surface in ha
ered to be salmon habitats. the Rhine Spawning area Juvenile habitat
There were many old salmon
rivers in the Middle Rhine region. Lower Rhine Ruhr + Volme etc. * 3,5
On the right banks of the Rhine, Wupper + Dhünn * 42,4
Sieg + Agger 20,1 150,0
the R. Saynbach, Lahn and Wis-
per drain the Westerwald and Middle Rhine Ahr 18,0 90,0
Taunus. On the left bank the R. Saynbach + Brexbach 2,3 7,0
Moselle: Sauer + Our 5,5 71,0
Ahr, Nette, Moselle and Nahe Moselle: left bank tributaries
draining from Eifel, Hunsrück Prüm, Kyll + X 12,7 14,8
and Vosges flow into the Rhine. Lahn: Mühlbach, Dill, Weil, Banfe 1,5+* 3,0+*
Lahn: Laasphebach 0,3 4,0
The R. Main and its former
Wisper 0,3 1,1
salmon tributaries from Oden-
wald and Spessart are right bank Upper Rhine Main + Hessian Kinzig, Rodach Kinzig 2,0+* Kinzig 8,4+*
tributaries to the Upper Rhine. Lauter 0,4 4,0
Ill: Bruche, Lièpvrette, Fecht,
Formerly, the R. Neckar used to Thur, Doller 2,5 70,0
be a salmon river, just as the Old bed of the Rhine 3,5 64,0
Black Forest rivers Alb, Murg, Alb, Murg, Rench, Kinzig in Baden 2,5 180,0
Elz + Dreisam * *
Rench, Kinzig and Elz. On the
left banks of the Rhine the salmon High Rhine Wiese 0,3 1,2
migrated from the Upper Rhine Birs 1,0 10,7
Ergolz 0,2 1,2
into the tributaries Lauter, Ill and
its tributaries from the Vosges, TOTAL 73,1 726,3
among them the R. Bruche.
* unknown at present
11
11
11Photo: Hajo Wetzlar
Old bed of the Rhine
F u t u re s a l m o n p o p u l a t i o n s
Unfortunately, many of the repro- 1 million of which survive to the grounds. It is estimated that be-
duction habitats capable of carry- stage of a smolt migrating down- tween 70 and 210 adult salmon
ing salmon are isolated in the riv- stream. 700.000 smolts may rear may return. In the tributaries to
er network. In the tributaries, hy- on 700 ha juvenile habitat.Once the lower R. Lahn there are 1.5
draulic engineering facilities of- a new stock of Rhine salmon will ha spawning grounds and 3 ha
ten interrupt subnatural river have developed, it may be ex- juvenile habitats. This means that
sections and a chain of barrages pected that 1-2% of salmon re- 30 to 90 salmon are expected to
cuts off their connection with the turn from the sea (ICPR 1994). return.
main channel. This particularly
Then the salmon population
applies to the R. Moselle, Main, In the R. Sauer and Our in Lux-
achievable on the medium
the Upper Rhine upstream of If- term will amount to 7.000 to emburg between 700 and 2,100
fezheim and the High Rhine. 21.000 adult salmon. salmon are expected to return to
The inventory of suitable spawn- This only represents a fraction of the 6 ha of spawning grounds
ing grounds and juvenile habi- the former population, but is and about 70 ha of juvenile habi-
tats serves as basis for a rough es- more than the estimate of 1999. tats.
timate of the carrying capacity Even though habitat improve- In the Alsacian tributaries to the
for future salmon populations. ment measures may on the long R. Ill some 50 ha of juvenile fish
A female salmon deposits at max- run increase this number, the habitats have been mapped. This
imum 10.000 eggs on 100 m2 of ICPR is perfectly aware of the fact means that between 500 and
gravel bed. About 1 %, that is that, due to hydraulic measures 1,500 returning salmon may be
100 salmon per 1.000 m2 juve- and water uses in the Rhine sys- expected.
nile habitat survive to migrate tem, the former size of salmon
downstream. If later on only 4 of stocks can never be restored. If migratory routes were not dis-
them return from the ocean to rupted, 600 to 1,800 adult
spawn, the stock of salmon sur- In the different tributary systems, salmon might return to the old
vives. Probably hardly half of the the surface of juvenile habi- bed of the Rhine with its 64 ha
adults returning from the ocean tats is the limiting factor as juvenile fish habitat.
reproduce successfully. long as it is not about 10 times
the surface of the spawning
1 hectare of juvenile habitat
may annually produce a pop- grounds. In the Northrhine-West-
ulation of 10 to 30 adult re- phalian R. Sieg system there are
turning salmon. 20 ha of spawning grounds as
According to the present state of opposed to some 100 ha juve-
knowledge, the Rhine system to- nile fish habitats. Therefore, the
day hosts 100 ha spawning potential adult salmon popula-
grounds and 700 ha juvenile tion does not amount to 2-
Photo: Hajo Wetzlar
habitats. On 100 ha spawning 6,000, but only to 1-3,000.
grounds in the Rhine system In the R. Saynbach watershed
some 10.000 female salmon may there are only 7 ha of juvenile
deposit 100 million eggs, about habitat for 2.3 ha spawning
Old bed of the Rhine
12Salmon habitat Dead wood, such as branch-
m e a s u re s es, bushes and trees may be
placed in a brook on purpose
The high ecological demands of to considerably increase struc-
salmon on their spawning and tural diversity. Often gravel
nursery grounds require particu- banks which salmon prefer for
lar measures for renaturing for- spawning form in the shadow
mer salmon carrying rivers. of the current.
Damming and river training have
often reduced flow velocity, silted
up gravel banks and, in many
cases rivers banks are artificial.
Within the ICPR Salmon 2000
Photo: Max Lauff
programme, many former juve-
nile salmon habitats have been
prepared: gravel banks have
been loosened and cleaned, river Renatured R. Sauer in Luxemburg
bank stabilizations have been re-
moved.
In the R. Sauer in Luxemburg, a
tributary to the R. Moselle, former
floodplains and a side channel to
the Sauer were renatured as a
part of ecological flood protec-
tion measures. Enlarging the riv-
er profile has restored the river
dynamics of the Sauer and
Photo: O. Niepagenkemper
helped develop natural river bed
and bank structures.
If channel bed sills and weirs no
longer having any function are
lowered, this will improve river Loosening gravel banks in the R. Sieg
patency and dynamics. Addition-
ally, there are different possibili-
ties of renaturing rivers or en-
hancing their dynamics, even
without any excavation:
River maintenance should be
reduced to a minimum and
river bank stabilizations should
not be maintained but re-
moved wherever possible.
Photo: Bernd Stemmer
River bank stripes should re-
main out of use in order to re-
duce the input of fertilizer and
pesticides.
Dead wood in the river
132 Open migration routes Weirs of hydroelectric power
plants obstruct upstream fish mi-
gration, turbines are problematic
for downstream travelling, even
though fish passages exist. Of-
ten, fish ladders were miscon-
structed and too little attraction
water made it difficult for fish to
find the entrance to the ladder
With a view to increasing the stock of salmon in our rivers obstructed by several weirs,
(PEDROLI 1991). Fish protection facil-
barrages, mills (...) so that salmon formerly migrating upstream no longer have any
access, the construction of salmon ladders (salmon ladders, fish ways, fish passages) is ities for downstream migration
urgently required. Such facilities will permit salmon to reach the overshot water of weirs bypassing by turbines are urgent-
which are too high to be lept over in order to reach the spawning grounds in the upper ly required.
regions of the rivers. The re-establishment of linear
Meyers Encyclopedia, vol. 6, Leipzig and Vienna (1894) river patency, that is of up- and
downstream fauna migration in
the Rhine and its side channels
has made variable progress and
Rhine 2020 is often still in the planning
Restoration of ecological patency with the help of bypass rivers or
auxiliary migration facilities (fish passages or the like). phase. However, many examples
of the main stream, e.g. at barrages prove that it is worth while the
of the tributaries figuring in the programme on migratory fish, if effort. More and more salmon
necessary by removing weirs which are no longer used spawn upstream places where
IKSR (2001) p. 13
obstacles have been removed.
More than a hundred years ago, obstacle for fish migration - lead- The ICPR demands to develop
many mill weirs already disrupted ing to a mortal infarctus. subnatural solutions when re-
fish migration routes. But from Today, one of the prerequisites moving obstacles in the river. Pre-
time to time the mills did not for reintroducing migratory fish is cise proposals have been made
work, weirs were neither too to open migration routes. Many to remove all weirs without wa-
high nor too sophisticated so reproduction habitats still exist ter rights and to build subnatural
that some fish managed to slip but are not accessible. Some of fish passages, such as block
through or to jump over. The first the "Salmon 2000" projects are ramps, bypassing the remaining
fish passages were built. Never- designed to put things right. In a weirs. Technical solutions such as
theless, less and less migratory first step, and parallel to the pro- Denil or vertical slot passages
fish reached the spawning ceedings for habitats, obstacles have also proved to be efficient
grounds in the Rhine tributaries. to migration have been inven- in places, where there is little
This was one of the main reasons toried and mapped. Within the room. Some fish passages should
for why Rhine salmon died out. inventory demanded by the Wa- be equipped with fish viewing
River training in the 19th and ter Framework Directive, new windows and monitoring sta-
20th century targeted at facilitat- weir registers are drawn up and tions.
ing navigation, at protecting will be presented in the begin-
from flooding and at producing ning of 2005.
hydroelectric power. The side ef-
fects of these measures on nature
were underestimated. Many fish
Photo: BFS, J. Schneider
are heavily injured on their way
downstream through rotating
turbines of hydroelectric power
plants. But, above all, river train-
ing proves to be a considerable
Salmon smolts after passing through
turbines
14Rhine delta
In the Netherlands, the Rhine
splits into the three branches IJs-
sel, Nederrijn / Lek and Waal.
Additionally, near the estuary, the Driel Amerongen
Meuse is connected to the Waal.
At the time being, fish can travel Photo:
Fish passage Driel, Tom Buijse
upstream from the ocean through Fish passage Amerongen, Cees Witvliet
Fish passage Hagestein, RIZA Lelystad
the Nieuwe Waterweg, pass by
IJssel
the port of Rotterdam, through sea
the R. Waal and into the Rhine
without coming across any ob-
Hagestein
stacle. But the other gates to the
Rhine, the sluices at the closure
embankments of Haringvliet and
IJsselsea are accessible to a lim- Amerongen IJssel
ited extent only. It is planned Hagestein Driel
Haringvliet Nieuwe
that, from 2008 on, the Haring- estuary Waterweg LEK
vliet sluices will be partly opened. Westervoort
WAAL
The extent of opening depends
on the discharge of the Rhine
GERMANY
and will be monitored until MAAS
Lith
Woudrichem
2012. After this period, a deci-
sion will be taken with respect to
the question whether the sluices
are to be opened more widely,
thus also admitting tidal influ-
ence (see: www.haringvlietsluizen.nl). BELGIUM
Three new fish passages have
been built bypassing the bar- 2001 the first of them, built at
rages in the Lek. By the end of the Driel barrage, was put into
Measures: service. Construction of the fish
Hydroelectric power plant passages Amerongen and
in bypass river
Hagestein was accomplished mid
Fish passage 2004, their functionality will be
Mechanical device protecting
e. g. rough ramp fish from entering the tested in 2005/6.
turbine, e. g. fine screen
(5-10 mm) or rotary screen
Bypass for downriver
Lower Rhine
migrating fish
• at the surface for Further weirs have been altered or
salmonid smolts lowered in the tributary systems of
• at the bottom for eel Hydroelectric
power plant
the Ruhr, Wupper and Sieg.
Pilot facilities protecting down-
stream fish migration are
planned for the turbines. They
Fish passage
are important not only for
Sufficient minimal flow e. g. bypass river salmon and sea trout smolts, but
for all river fish species. Further
details are given in the North-
rhine-Westphalian programme
on migratory fish (MUNLV 2003).
Grafik: Kernteam WFP NRW, Dr. Frank Moll
15Along the salmon to surmount the Lahn- Upper Rhine
Middle Rhine stein obstacle”.
Upstream the junction with the
In 2002, a weir in the R. Ahr in On the Upper Lahn in Hesse R. Kinzig, there are five barrages
Rhineland-Palatinate was trans- most obstacles are side weirs in the lower R. Main without any
formed subnaturally and, at the which fish with a good swim- suitable fish passages. These will
same time, the river bottom was ming capacity manage to cross be altered or reconstructed by
cleared from concrete. Two more and 16 of the 56 weirs are 2006. In the Hessian R. Kinzig it-
weirs have been changed and equipped with fishways. In the self many weirs have been re-
modifications are planned for an- R. Dill, a tributary to the Lahn, moved or equipped with fish-
other six. 12 of the 37 transversal struc- ways. At present, there are only
two obstacles left in the lower
Kinzig but several weirs subsist in
the Kinzig tributaries. In particu-
lar, hydroelectric power utiliza-
tion poses major problems (VSDF
2003, p. 63).
While there are no obstacles from
Photo: Georges Muller
the Rhine estuary through the R.
Waal until the Iffezheim barrage
some 700 km upstream, 10 bar-
rages obstruct the 164 km of the
Franco-German Upper Rhine be-
Blasting a weir in the loop of the R. Sauer in Luxemburg with aids from Rhineland-Palatinate tween Iffezheim and Basel.
France, Germany and the opera-
Along the R. Nahe downstream tures have been equipped with tors of the hydroelectric power
the mouth of the R. Glan there fish passages, so that patency is plant have jointly financed the
are six weirs without any func- granted along the 30 river km be- construction of a fish passage by-
tional fish passages. In the R. tween the estuary and Herborn. passing the lower most barrage
Glan, a tributary to the Nahe, the Until 2004, all of the 10 weirs on at Iffezheim which is operational
modification of weirs has begun. the R. Weil, a tributary to the since June 2000. Subsidised by
Lahn, were changed (RP Giessen). the EU Life programme, the ICPR
In the Saynbach-Brexbach river participated in financing the con-
system, where exemplary modifi- Since 2002 the lower Wisper is struction costs amounting to an
cations were carried out on six patent for migratory fish. overall 8 million Euros. Now
weirs between 1996 and 1999, salmon and other migratory fish
all weirs are supposed to be sur- Apart from the first one, the fish do not encounter any obstacles
mountable for fish by 2005 (Aktion ladders at the 10 weirs on the on their way from the North Sea
Blau in RP, see VDSF 2003 p. 48). lower R. Moselle are difficult to to the R. Ill in Alsace and the R.
cross for fish (ICPR 1999, report 103, p. Rench in Bade-Württemberg.
On the lower R. Lahn in Rhine- 21). At the time being, Rhineland- French and German Industrial
land Palatinate 8 of 11 weirs dis- Palatinate is working on a study Fisheries Boards and administra-
rupt fish migration, among them aimed at their alteration. In the tions jointly monitor fish migra-
the lowermost weir in Lahnstein, R. Sauer, a tributary to the tion at the Iffezheim monitoring
the salmon "gate to the R. Lahn” Moselle, 4 weirs have been re- station (see success control p. 24).
belonging to the German navi- moved at Rosport-Ralingen in
gation administration. In 2002, Luxemburg and one fish passage Gambsheim, the next upstream
headlines of the Rheinzeitung has been modified. 3 weirs on barrage, will also be equipped
read:"When the journey ends at the R. Our, a tributary to the R. with a jointly financed fish pas-
the weir ..." and "No way for Sauer, were altered. sage. Construction work of the
16Release rivers in the German and
French Upper Rhine area
Release period: 1993 - 2001
Patency of transversal
structures for samonids
patent
restricted patency
strongly restricted patency
hardly or not patent High Rhine
salmon river In the Swiss High Rhine, many
barrages obstruct the way to-
wards the last two freely flowing
stretches of the Rhine which
would be suitable for spawning.
In the High Rhine tributaries
Wiese, Birs and Ergolz, eight ob-
stacles have been altered since
the mapping of obstacles in
1996 by building bypass chan-
nels, ramps, etc. for fish migra-
tion.
In the French R. Ill and its tribu-
tary Bruche, several basin pas-
sages have already been built,
others are still due. In December
2000, a basin passage was put
Map: LFV BW into operation at the hydroelec-
tric power plant Erstein on the R.
baffled pass similar to that at If- Ill, some 30 km south of Stras-
fezheim began in spring 2004 bourg, opening the Ill tributaries
and the fish passage is scheduled Fecht, Thur and Doller for
to be operational in the begin- salmonids.
ning of 2006. Additionally, this
fish passage will include a large In the Baden-Württemberg tribu-
fish viewing room open to the taries Alb, Murg, Rench, Kinzig
public. and Elz many weirs have been
But there are more barrages in modified or equipped with fish
the Upper Rhine between Gambs- passages. But the turbines of
heim and Basel which, so far, dis- many small hydroelectric power
Energiedienst AG
rupt fish migration. The ICPR has plants cause considerable prob-
commissioned a feasibility study lems for downstream fish migra-
on the restoration of the Upper tion. Additionally, too little water
Rhine river patency, the results of is flowing through many of the Model of the fish passage at the
which will be presented in 2006. bypass rivers. Rheinfelden hydroelectric power plant
173 Release juvenile fish
The main ICPR target set out in the same still be hatched and re-
the “Ecological Master Plan for leased for some time to come.
the Rhine” was to reintroduce mi- Still, eggs are today partly collect-
gratory fish such as salmon and ed from adult salmon returning
sea trout (ICPR 1991). As for the sea from the ocean! The ICPR hopes
trout, replenishing of the stock that, as time passes by, a stock of
Photo: Adam Schmitt
still existing in the Rhine system Rhine salmon adapted to local
was to be based on natural re- conditions will develop and natu-
production and on the catch of rally reproduce in the Rhine sys-
mature adults. Since the salmon tem without any artificial sup-
Information board for fishermen along the
died out in Rhine system in the porting measures. This is one of Allier helping them to recognize salmon
fifties of the 20th century, a new the targets set out in “Rhine
stock of Rhine salmon had to be 2020”.
created. ly reduced. It is admitted that di-
Therefore, eggs were collected Today, salmon migrating several verse stocks of wild salmon and a
from other wild salmon stocks hundreds of kilometres upstream broad genetic variety could offer
and raised in fish hatcheries be- (almost 1000 km) are only found more room for a natural selection
fore the juvenile fish were re- in the French Loire/Allier-system. and the adaptation of new
leased into suitable habitats. But, for the last 30 years, even salmon populations to present
Having thus again started off the the Loire salmon has been artifi- habitats. After all, the former
salmon life cycle and achieved cially supported (PEDROLI 1991). stock of Rhine salmon did not
the aim set out in “Salmon 2000”, consist of one homogenous, but
that is downstream migration, re- In future, the number of stocks probably of several different pop-
turn of adult salmon from the of origin from which salmon ulations living in the different trib-
ocean and even natural repro- eggs destined for the Rhine sys- utaries. However, certain scien-
duction, juvenile salmon must all tem are imported will be marked- tists fear that, if different stocks
are cross-bred, in particular artifi-
cial reproduction may lead to a
Stocking in the Rhine Origin of salmon eggs loss of genetic fitness (Schneider and
region (1999-2003) importation Returning adults others 2004).
Germany / NRW Ireland, Sweden Yes! All stocking exercises implying mi-
D / Rhineland-Palatinate France, Sweden, gratory fish are documented in a
Denmark, Ireland, Spain,
central data base in NRW (LÖBF)
Scotland Yes!
which the ICPR may use since
D / Hesse France, Denmark, Sweden
2002. The table below gives an
Yes!
overview over the stocking exer-
D / Bavaria Ireland, France
cises of the past five years (Stocking
D / Bade-Württemberg Ireland, Sweden Yes!
exercises 1994-98, see ICPR 1999, report
Luxemburg France Yes!
(Moselle estuary) no. 103, p. 32).
France France, Sweden Yes!
Switzerland France
18Photo: ASR Strasbourg
Photo: Armin Nemitz
Children help releasing small salmon Releasing salmon alevins
Stocking juvenile salmon in the Rhine river system
1999-2003
Country River system Stocking exercise
Germany/ Ruhr ca. 5.4 million
Northrhine-Westphalia Wupper
Photo: ASR Strasbourg
Sieg
Lahn
D / Rhineland-Palatinate Sieg ca. 2.3 million
Ahr
Saynbach
Mosel / Kyll, Prüm
In most cases, salmon were re- Lahn / Mühlbach
leased as alevins or parr. So,
D / Hesse Lahn / Dill, Weil ca. 1 million
during the past 5 years,
Wisper
some 11 million salmon
Main / Kinzig
have been released into
the Rhine catchment. D / Bavaria Main ca. 0.2 million
D / Bade-Württemberg Alb ca. 0.3 million
According to fisheries experts,
Murg
this considerable stocking exer-
Rench
cise was necessary in order to
Kinzig / Erlenbach,
make up for the high natural
Gutach, Wolfach
mortality of young salmon (see
salmon population estimates p. 12). Luxemburg Sauer / Our ca. 0.2 million
France Old bed of the Rhine ca. 1.6 million
Ill
Switzerland Rhine ca. 0.3 million
D, L, F, CH entire Rhine ca. 11.3 million
19Rhine delta tween stocked salmon and wild
descendants. As soon as the
In the Dutch Rhine delta, there count of downstream migrating
smolts shows that natural repro-
Foto: Armin Nemitz
are no suitable salmon or sea
trout spawning grounds and duction leads to a sufficient num-
thus no stocking exercises. How- ber of descendants, stocking ex-
ever, big mature salmonids re- ercises can be stopped.
Releasing salmon in the upper R. Sieg
turning from the North Sea are
monitored (see p. 27). Middle Rhine
ing exercises have been consider-
Lower Rhine From 2000 on, salmon of two ably reduced.
different origins were used for
Annually, about one million juve- stocking exercises in Rhineland- In Hesse, salmon are released in-
nile salmon are released into the Palatinate. Eggs collected from to the R. Dill and Weil, both trib-
Rhine tributaries from the low salmon of the French Loire-Allier utaries to the R. Lahn and into
mountain ranges in Northrhine- stock were hatched and raised to the R. Wisper, flowing into the
Westphalia. Most of them are parr in a fish hatchery before Rhine in the Rheingau. In future,
alevins hatched from eggs or few they were released into the Lahn only Swedish Ätran salmon will
weeks old fry. Apart from that, ju- affluent Mühlbach and into the be used for stocking exercises in
venile parr, yearlings and smolts R. Ahr. Young parr from the these rivers.
are released. It is expected that, Swedish rivers Lagan and Ätran Since 2001, salmon are released
from 2004 on, the first marked were released into the R. Sayn- into the upper R. Lahn near Laas-
adult salmon of the Swedish bach. Here too, eggs are collect- phe in Northrhine-Westphalia.
Ätran stock used since 2003 will ed from salmon returning from
return. That means that, in fu- the ocean and precocious males, In Luxemburg, salmon are re-
ture, the importation of salmon presumably descendants of natu- leased into the R. Sauer, a tribu-
eggs can be reduced in favour of ral reproduction, are used as tary to the Moselle and its tribu-
the “home production”. Some sperm donators. Since 2001, and tary, the Our. The first descen-
salmon manage to pass by moni- without any previous stocking dants of returning salmon were
toring and catching stations and exercises, the R. Nette flowing in- released in 2002. Their parent
celebrate veritable marriages in to the Rhine between the tribu- fish had been caught and eggs
nature. Others are let pass on taries Moselle and Ahr is colo- had been collected at the first
purpose in order to enhance nat- nized by “straying” salmon (see p. fish passage on the Moselle in
ural reproduction. It has been de- 26, 27). Since 1996 salmon are al- Koblenz (D) for hatching in a fish
cided that “with a view to deter- so released into the Eifel R. Prüm farm in Nassau.
mining the success of natural re- and Kyll flowing into the Moselle.
production” (MUNLV 2003, p. 21) In future, Rhineland-Palatinate
only young marked salmon will and Luxemburg will mainly use Upper Rhine
be released into certain brooks. eggs of salmon from the Swedish
This allows to distinguish be- R. Ätran for stocking exercises. Since 2001, salmon are reintro-
duced into the Hessian Kinzig, a
The number of sea trout has in- tributary to the R. Main as well as
creased in the estuaries of Rhine into the Kinzig tributaries. In
tributaries in Rhineland-Palati- 1994, and since 1998, young
nate, and even before the year salmon alevins are released into
2000 their eggs were collected the Francian R. Main and its trib-
for artificial reproduction and utary, the R. Rodach in Bavaria.
Photo: Bernd Stemmer
hatching. Due to a natural in-
crease in numbers and probable In Baden-Württemberg salmon
natural reproduction (e.g. R. are released into the Rhine tribu-
Saynbach, Nette) sea trout stock- taries from the Black Forest. Annu-
Collecting eggs from returning salmon
20ally, up to 90.000 young salmon
of Irish origin were released into
these rivers. An even more inten-
sive co-operation in salmon hatch-
ing is planned with France and
salmon of homogenous origins
are strived for in co-operation with
Switzerland. Thus, in future, all re-
turning salmon may be identified
by their origins in the Iffezheim
monitoring station and their eggs
Photo: Bernd Stemmer
may be collected without taking
any genetic risk. (LV BW 2002, SCHNEI-
DER u.a. 2004).
Salmon rearing in the Hasper dam
High Rhine
Since 1999, young salmon from
the Adour-Nive river system in
the southwest of France are re-
leased into the Swiss High
Rhine. They are no longer put
into the tributaries St. Albanteich,
Birs and Wiese, as was the case
in the past years, but released
near the confluence of these
rivers with the High Rhine.
Photo: ASR Strasbourg
Stocking salmon in the R. Fecht, a tributary to the Ill
In France, Rhine salmon are
stocked in the Old bed of the
Rhine and the R. Ill. The fry are
mostly of Allier origin, partly they
come from Brittany or they are
descendants of adults returning
to the Rhine and which, since
2000, were caught in the Rhine
at Iffezheim or in the R. Bruche
downstream the Avolsheim bar-
rage. Artificial fertilization pro-
duced more than 100,000 eyed
eggs. In future, stocking exercises
will be based on adults from the
Allier reproducing in fish farms
and on adults returning from the
ocean.
214 Success control
Monitoring the fish population m o n i t o r i n g s t a t i o n s for
by drawing up an inventory of migratory fish. The ICPR recom-
spawning grounds, fishery bio- mends to install such monitoring
logical inventories based on elec- stations near the estuary of each
tro-fishing and fyke nets, marking larger tributary.
tests and monitoring stations fig-
Photo: StVA Köln-Bonn
ure among the success control
measures within Salmon 2020.
So far, there are six permanent
Buisdorf monitoring station
From the very beginning on, the
salmon programme was accom-
panied by success control and re-
search. This helped to establish
and improve the effectiveness of
stocking and protection meas-
ures. In this connection, as well
Photo: ASR Strasbourg
as in case of stocking measures,
voluntary fisheries associations
and nature protection associa-
tions had a large part in the suc-
Iffezheim monitoring station
cess.
Future permanent monitoring stations
In its “Ecological Master Plan” the (six already exist)
ICPR demanded success control,
such as fishery biological invento- Rhine section Country River branch, Weir
tributary
ries and monitoring of new fish
passages in order to prove the Rhine delta NL IJssel Westervoort
Rhine ecosystem improvement Lek Hagestein
(ICPR 1991). Waal Woudrichem
Fish viewing window in the Lower Rhine D / NRW Dhünn Auermühle
Iffezheim monitoring station Sieg Buisdorf
Agger Troisdorf
Middle Rhine D / RP Moselle Koblenz barrage
L Lahn Lahnstein barrage
Sauer Rosport-Ralingen
Upper Rhine F/D main stream Iffezheim
F/D main stream Gambsheim
Photo: ASR Strasbourg
F Ill Straßburg
F Bruche Avolsheim
High Rhine CH – –
22Diversity of migratory fish
Which species return to the Rhine?
Atlantic salmon Houting
(Salmo salar) * (Coregonus
oxyrhynchus)*
Sea trout Common sturgeon
(Salmo trutta) (Acipenser sturio) † *
Photos: ASR Strasbourg, aus Vogel&Hofer, Stefan Staas, Bernd Stemmer
Allice shad Sea lamprey
(Alosa alosa) * (Petromyzon marinus) *
Thwaite shad River lamprey
(Alosa fallax) * (Lampetra fluviatilis) *
† Extinct in the Rhine individuals returning natural reproduction increasing stocks
* = FFH-species according to directive 92/43/EEC (see p. 6 this brochure)
Eel
(Anguilla anguilla):
Photo: Peter Rey
another migratory fish which however spawns in the sea and migrates
upstream rivers at the stage of a juvenile fish.
Since 1992, migratory fish are and salmon were equipped with Many migratory fish, among
monitored in the Dutch Rhine radio transmitters. On their way them a growing number of rare
delta. At selected locations, test upstream, 34 of the 580 sea species such as thwaite shad
catches are carried out with nets trout passed by the estuary dam, and houting have been caught
and the by-catches of profession- 103 by the Nieuwe Waterweg in the Rhine delta and in the
al fishermen are evaluated. Be- and 70 by the sluices on the Har- IJsselsea (WINTER et al. 2003).
tween 1994 and 2003 727 adult ingvliet (BIJ DE VAATE et al. 2003). So
salmon and 1327 sea trout were far, 12 of these sea trout and one Along the Northrhine-West-
observed (HARTGERS & BUIJSE, WINTER salmon have been registered phalian Lower Rhine research in-
and others 2003). heading upstream the R. Sieg to- to which migratory fish are re-
Between 1996 and 2000 the wards the spawning grounds. turning is carried through in the
routes taken by migratory fish re- It has been proved that salmon tributary Lippe. A permanent mi-
turning from the North Sea and and sea trout smolts marked in gratory fish monitoring station
travelling through the Rhine Northrhine-Westphalia and has been built at the lowermost
delta were subjected to telemet- Baden-Württemberg have weir across the R. Sieg near Buis-
ric research. To this end, sea trout reached the North Sea. dorf entailing costs of some
23650,000 Euro. It was taken into
operation in the beginning of Counts at the Iffezheim barrage between 2000 and 20031
2000 and consists of a basket
trap, two rooms for keeping Long distance migratory fish
living fish as well as installations Eel (Anguilla anguilla)
2
1.257
to measure fish and collect their Thwaite shad (Alosa fallax) 3
1
eggs. Atlantic salmon (Salmo salar) 318
The station has proved to be per- Allice shad (Alosa alosa) 11
formant. Apart from migratory Sea trout (Salmo trutta trutta) 988
fish – 564 salmon, 205 sea trout Sea lamprey (Petromyzon marinus) 342
and downstream migrating river
Other fish species
lamprey – many other fish species
Grayling (Thymallus thymallus) 5
were registered until the end of
Brown trout (Salmo trutta fario) 109
2003, among them barbel, nase,
Brook trout (Salvellinus fontinalis) 5
chub and pike. The highest num-
Barbel (Barbus barbus) 23.994
ber of upriver migrating salmon
Perch (Perca fluviatilis) 21
Bream (Abramis brama) 12.109
Family of bream (small) (Abramis spec.) 4
83
Chub (Leuciscus cephalus) 624
Graskarp (Ctenopharyngodon idella) 4
Bullhead (Cottus gobio) 3
Gudgeon (Gobio gobio) 6
Photo: Peter Rey
White bream (Blicca bjoerkna) 135
Dace (Leuciscus leuciscus) 88
Pike (Esox lucius) 1
Upriver migrating barbel Crucian carp (Carassius carassius) 3
Carp (Cyprinus carpio) 10
was registered in October of
Ruffe (Gymnocephalus cernua) 8
every year. Grilse, that is early re-
Nase (Chondrostoma nasus) 7.366
turning salmon prevailed, meas-
Burbot (Lota lota) 1
uring between 70 and 75 cm
Asp (Aspius aspius) 6.894
and weighing about 3 kg after
Rainbow trout (Oncorhynchus mykiss, Salmo gairdneri) 18
one year ocean residence .
Roach (Rutilus rutilus) 1.611
Further permanent monitoring
Rudd (Scardinius erythrophthalmus) 6
Salmonids (small) (Salmonidae) 5
73
Tench (Tinca tinca) 10
Bleak (Alburnus alburnus) 2
317
Wels (Siluris glanis) 15
Photo: O. Niepagenkemper
Vimba (Vimba vimba) 4
Pikeperch (Stizostedion lucioperca) 20
White-eye bream (Abramis sapa) 402
Sum6: 34 species 56.862
1
Counting periods: 13.6. - 31.12.00, 1.1. - 31.12.01, 4.3. - 31.12.02, 1.1. - 31.12.03.
Jumping salmon at the Sieg weir near Buisdorf 2
Eel and bleak only partly counted.
3
Thwaite shad not identified with certainty, perhaps allice shad
4
Specimen belonging to the family of the bream below 30 cm length cannot be identified
stations have been installed near
with certainty (bream, white-eye bream, zope).
Troisdorf on the R. Agger and at 5
Salmonids below 25 cm length cannot be identified with certainty.
6
the Auermühle mill in the R. The sum of fish counted represents a minimum number of upstream migrating fish
using the passage.
Dhünn.
Between 2000 and 2002 the
French and the Germans have
24by turns counted the fish caught 519 sea trout have been caught 2. Do fish migrate into the High
in fyke-net in the monitoring sta- and marked in the monitoring Rhine tributaries Birs, Ergolz
tion of the fish passage Iffezheim station at the Moselle barrage in and Wiese for spawning? -
on the Upper Rhine (s. p. 17, 22). Koblenz before being released Yes, evident proof was given
This was done in close co-opera- further upstream. In April 2000, (ASR 2004).
tion between the Association the first two river lamprey were
Saumon-Rhin (ASR), the Conseil caught in the Hessian R. Wisper. Downstream migration
Supérieur de la Pêche, the Lan- They had presumably migrated According to estimates, the sur-
desfischereiverband Baden and upstream to spawn. River lam- vival rates from the release of
the Regierungspräsidium Karls- prey have also repeatedly been salmon alevins to the down-
ruhe. Until the end of 2001, the spotted in the R. Nette. stream migrating smolts vary be-
Bundesanstalt für Gewässer- tween 5 and 10 %. Therefore,
kunde and from 2002 on the From the Upper Rhine the “smolt production” is estimat-
ASR monitored upstream fish into the Black Forest ed on the basis of the sum of re-
migration with video cameras. and Alsace leased alevins.
Since 2000, far more than Sea lamprey, a surprisingly high
50.000 fish belonging to at least number of which migrate up- Lower Rhine
34 species have used this fish stream using the Iffezheim fish During the past years, up to
passage. Among them, more passage, have been equipped 100,000 salmon smolts annually
than 300 adult salmon, almost with radio transmitters before be- migrated downstream the
1,000 sea trout, more than 300 ing released into the R. Rench. Northrhine-Westphalian Rhine
sea lamprey, 11 allice shad and a Evidence has been given of one tributaries into which alevins are
new species in the Rhine, more individual which managed to released and travelled to the
than 400 white-eye bream. pass by the vertical slot pass at ocean. In 2003, some 15,000
the Memprechtshofen mill. smolts migrated downstream the
From the Rhine delta to Redds dug by sea lamprey have Sieg river system in Rhineland-
the Lower Rhine been spotted in the R. Murg as Palatinate.
In 1999, 81, respectively 47 sea well as in the Ill river system.
trout were caught in the R. Sieg Middle Rhine
system and in the Dhünn, a trib- From the Upper to the In 2003, approximately 8,000
utary to the Wupper. 5 of them High Rhine smolts were raised in the Sayn-
were marked individuals and In 2003, upon request of the bach river system, 500 of them
revealed their migration route: Swiss Bundesamt für Umwelt, descending from natural repro-
4 originated from the "Project Wald und Landschaft, the Associ- duction (see p. 27). The same year,
migratie zeeforel" in the Nether- ation Saumon-Rhin caught sea some 2000 smolts left the Sauer
lands which means that they had trout in the Iffezheim fish pas- river system in Luxemburg.
been marked in the Rhine estu- sage, marked them with radio
ary, the other one had been transmitters and released them Upper Rhine
marked in Denmark. Since 1999, into the Old bed of the Rhine up- According to estimates, annually
sea lamprey have repeatedly dug stream of Kembs (see map p. 17) 25 – 45,000 smolts migrate
redds in the R. Sieg and Dhünn. in order to find the answers to downstream from the French
two questions: Rhine catchment. Since 1992,
From the Middle Rhine 1. How do fish behave when electro-fishing methods have
into the tributaries encountering the barrages on been used to monitor the quality
By the end of 2003, three sea the High Rhine? - Some sea of release sites and of juvenile
lamprey had been registered trout used the fish passage to habitats in the Old bed of the
after depositing eggs in the R. by-pass the Rheinfelden hy- Rhine and the Ill river system. The
Saynbach. Since 1996, sea trout, droelectric power plant, some results are as encouraging as
some of which were transported even used the navigation those in the release rivers in
to the subnatural Lahn tributary locks of the Birsfelden and Baden, where growth of juvenile
Dörsbach, have been caught at Augst-Wyhlen power plants salmon has been stated to be
the Lahnstein weir. Since 1992, on their way upstream. very satisfactory.
25R e t u r n f ro m t h e salmon even migrate upstream tion, only few returning salmon
ocean the R. Lippe, even though juve- succeed in travelling through the
nile fish have never been re- navigation locks. Since 1992, 46
In the Rhine delta, the Dutch leased into this river. Salmon also returning salmon have been
have detected adult salmon since started colonising the R. Ruhr be- caught in the Koblenz fish pas-
1994, by the end of 2003 their fore stocking exercises started in sage on the Moselle and have
number had grown to more this river. been released further upstream.
than 700. In the R. Lahn they are caught at
During 1996 to 2003, evidence the foot of the Lahnstein weir
In 1990, decennia after the old was given of some 250 salmon and brought to the IG Lahn fish
stock of Rhine salmon had died migrating upstream the tributar- hatchery where they are used for
out, the first salmon migrated up- ies to the Middle Rhine in artificial reproduction.
stream and unerringly swam Rhineland Palatinate and Hesse,
from the ocean through the most of them were found in the Since 1995, evidence has been
Lower Rhine and into the Sieg Saynbach river system (101). given of some 379 salmon re-
where stocking exercises had Since 2001, they even stray into turning to the Upper Rhine. After
started as early as 1990. Since the R. Nette to spawn, even the Iffezheim fish passage was
then, there is evidence that by though juvenile salmon have put into operation in 2000,
2003, more than 1000 salmon never been released into this salmon have also been identified
have migrated upstream the river. On the other hand, the in the R. Rench in Baden and in
Lower Rhine and its tributaries. weirs in the rivers Lahn and the Alsacian Ill river system.
Since 1998, individual adult Moselle disrupt upstream migra-
Return of salmon to the Rhine (see p. 19)
Section of River branches Stocking Stocking Return Returning First
the Rhine or tributaries exercise exercise1 start salmon2 larvae3
start (until 2003 in million) (until 2003 Individuals)
Rhine delta Waal, Lek, IJssel (NL) – – 1994 727 –
Lower Rhine Lippe (NRW) – – 1998 5 –
Ruhr (NRW) 2003 0,02 2002 4 –
Wupper (NRW) 1993 2,10 1998 92 2002
Sieg (NRW + RP) 1988 9,90 1990 991 1994
Middle Rhine Ahr (RP) 1995 0,82 1999 34 2000
Nette (RP) – – 2000 >4 2001
Saynbach (RP) 1994 0,75 1996 138 2000
Moselle/Sauer, Prüm, Kyll 1992 0,50 1995 46
(L, RP) –
Lahn/Mühlb., Dill, Weil 1994 0,90 1997 36 2000
(RP, He, NRW)
Wisper (He) 1999 0,18 2002 4 2003
Upper Rhine Main/Kinzig, Main + 1994 1,20 – – –
Rodach (He, Bay)
Alb, Murg, Rench, 1994 0,34 2000 4 –
Kinzig (BW)
Old bed of Rhine, Ill/Bruche 1991 2,80 1995 367 1997
etc. (F)
High Rhine Rhine + Ergolz, Birs, 1995 0,60 – – –
Wiese etc. (CH)
Sum ca.20 2450
millon.
1
Juvenile salmon, above all alevins, about 3-5 cm length, able to feed until some weeks old.
2
Salmon returning from the North Sea, about 50-100 cm length, 2 to 5 years old.
3
Salmon larvae of naturally reproducing returning salmon.
26All in all 2450 returning salmon
Photo: ASR Strasbourg
have been identified beyond any
doubt. The accurate number of re-
turning salmon might be ten times
as high. That means, that perhaps Salmon alevin
20,000 salmon have migrated into
the Rhine river system since 1990. to the Wupper on the Lower downstream to the ocean! Since
With an estimated release of 20 Rhine. In the Sieg system, 9 were 2001, some 10 to 20 % of the
million juvenile salmon since detected in the winter 1999/2000. annually downstream migrating
1988, and a maximum down- In the R. Naafbach, a tributary to smolts in the Saynbach river sys-
stream migration of 2 million the Agger in the Sieg system, a tem are descendants of naturally
smolts, salmon would, according large number of naturally repro- reproducing adult salmon.
to this estimate, have reached duced salmon alevins was It is highly probable that, in
the expected return rate of 1 caught and genetically tested in 2003, the first naturally repro-
per cent (see p. 12, 25). 2001, after their parents had duced salmon have migrated
been observed depositing eggs upriver from the ocean in or-
Natural reproduction some months earlier. Since 1999, der to spawn in the Saynbach
It is really true: salmon do repro- natural reproduction has been where they have participated
duce naturally in the Rhine sys- observed every year in the Sieg in digging more than 20 redds.
tem! In 1994, the first salmon lar- river system in Rhineland-Palati- It seems as if, for the first
vae were detected in natural redds nate. time, the life cycle of a new
dug into the Northrhine-West- A research project carried out by Rhine salmon population has
phalian Bröl, a tributary to the R. the Northrhine-Westphalian min- been concluded.
Sieg on the Lower Rhine. istry of environment looks into In the winter of 1999/2000, nat-
Then adult salmon chose to dig the question what rivers must be ural salmon reproduction was
their redds into more and more like for salmon to spawn natural- proved in the Mühlbach, a tribu-
brooks. These natural nursery ly. A pilot study carried out on tary to the Rhine. However, the
grounds are called Bruche, the R. Bröl, a tributary to the parent fish had been caught in
Dhünn, Naafbach, Wisper, Ahr, Sieg, is aimed at producing guide- the Ahr and transported to the
Nette, Saynbach, Brexbach, Elb- lines for Cleaning up salmon Mühlbach to which salmon have
bach, Sieg, Nister and Wisser- spawning rivers. no natural access.
bach (see table p. 26) . Since 2002, salmon are returning
In the winter 1998/99, 12 redds In the winter of 1999/2000, a to the smallest release river, the
dug by big salmonids were iden- redd was detected in the R. Ahr Hessian Wisper, and natural re-
tified in the R. Dhünn, a tributary on the Middle Rhine. A genetic production has been proved.
test carried out on an alevin taken
from this redd revealed it to be a On the Upper Rhine, natural
salmon. In the Mühlgraben near salmon and sea trout reproduc-
Photo: ASR Strasbourg
Heimersheim on the Ahr three tion has been observed in the Al-
naturally reproduced salmon parr sacian Ill river system since 1997,
were identified. and since 2000 migratory fish
In the R. Nette, a tributary to the have unobstructed access to this
Evidence of salmon hatch by combining
drift net and electro fishing Rhine located between Ahr and river system by using the Iffez-
Moselle, straying salmon have heim fish passage. In 2000, 21
been observed since 2001, and redds of large salmonids were
they reproduce naturally. detected in the Ill tributary
Bruche. In 2001, 37 were detect-
Photo: BFS, Jörg Schneider
In 2000, salmon stocking was
stopped in the Brexbach, a tribu- ed in the Bruche and 7 in the Altorf
tary to the Saynbach. Neverthe- side channel, in each of the years
less, annually 100 to 500 natural- 2002 and 2003 more than 200
ly reproduced smolts migrate salmon redds were counted.
Salmon spawning ground
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